How Can Wiring Be Hidden for Channel Letters on Glass Walls? Methods, Power Routing, and Installation Checks

Channel letters with concealed wiring installed on a modern commercial glass wall

A glass wall can make illuminated channel letters look lighter, cleaner, and more architectural than the same letters mounted on masonry. It can also expose every part of the installation that would normally disappear inside a solid wall. A loose cable, oversized power supply, visible connector, or poorly placed wireway may be noticeable from both sides of the glass. Reflections can make a small wiring issue look twice as obvious.

Channel letter wiring on glass walls is normally hidden by routing low-voltage cables through an existing frame or mullion, placing them inside a slim wireway or structural raceway, concealing them behind an opaque backer panel, or carrying them through a purpose-built support connected to an accessible remote power supply. The correct method depends on the glass construction, letter type, viewing angles, cable length, mounting load, and service requirements.

The cleanest result is rarely created by “finding somewhere to put the wire” after the letters arrive. It begins with a coordinated elevation, mounting drawing, cable route, power-supply location, and service plan before manufacturing starts.

Imagine a reception logo approved from the front: polished stainless-steel letters, balanced spacing, and even illumination. Installation day arrives, and the team discovers a black cable must cross 600 mm of clear glass to reach the ceiling. The letters are correct, but the finished wall is not. That small oversight explains why wiring should be treated as part of the visual design, not as an installation detail left until the end.

Why Is Wiring Hard to Hide on Glass?

Rear wiring and mounting details visible through glass behind illuminated channel letters

Glass removes the wall cavity normally used to conceal cables, connectors, mounting studs, and power leads. Every component may remain visible from the front, rear, side, or through reflections. A clean installation therefore depends on the glass type, frame layout, viewing angles, letter construction, cable route, and power-supply position being confirmed before the channel letters are manufactured.

What Makes Glass Different?

On drywall, concrete, brick, or a metal façade, a small hole behind each letter usually allows the low-voltage lead to enter the building. The cable connections and power equipment remain inside the wall or above the ceiling. Glass offers no comparable space directly behind the letters.

The problem becomes more difficult because transparent surfaces expose details that would be ignored on an opaque wall:

  • Cable jackets and printed cable markings
  • Wire connectors and splices
  • LED leads leaving each letter
  • Mounting studs, nuts, washers, and spacers
  • Adhesive pads and trapped air bubbles
  • Shadows created by cables behind the glass
  • Power supplies or junction boxes near the sign
  • Uneven wire lengths between separate letters

Tempered glass also limits last-minute changes. Holes normally need to be planned before tempering because an installed tempered panel cannot be drilled like acrylic, plywood, or ordinary metal. Laminated, insulated, coated, curved, and fire-rated glass can introduce additional restrictions.

A storefront team may approve an attractive front elevation while overlooking the rear of the sign. Once installed, every connector may be visible from inside the shop. The same installation can therefore look clean from the street and unfinished from the sales floor.

The following information should be confirmed before choosing a wiring method:

Glass informationWhy it matters
Glass typeDetermines whether drilling, clamping, bonding, or through-fixing may be considered
Panel thicknessAffects hardware selection but does not alone confirm load capacity
Tempered or laminated statusChanges how holes and edge loads must be handled
Coating or filmMay affect adhesive bonding and visual appearance
Panel sizeInfluences movement, vibration, and available support points
Frame profileDetermines whether a concealed cable route may exist
Existing or not yet producedDetermines whether holes and hidden inserts can still be planned
Rear-side visibilityDetermines how much mounting hardware must be concealed

A useful rule is simple: glass should not be treated as a wall with a clear finish. It should be treated as both the mounting surface and part of the visible sign.

Which Views Must Stay Clean?

A channel letter set on glass can be viewed from more directions than the elevation drawing normally shows. Wiring that disappears from one angle may become obvious from another.

For a storefront installation, the main views often include:

  • Street-facing front view
  • Interior rear view
  • Side view along the shopfront
  • View from an adjacent entrance
  • View from below when the sign is mounted above eye level
  • Reflections from neighboring glass panels
  • Night view when dark cables become more noticeable against illuminated letters

A reception logo may have even stricter requirements. People may sit behind the glass partition for several hours, making the rear wiring as important as the front appearance. A visible 100 mm cable transition may appear minor on a drawing but become the first detail noticed from a nearby meeting table.

Viewing distance also changes what can be accepted. A slim black cable placed beside a black mullion may be nearly invisible from 5 metres away. The same cable may look untidy from 500 mm away. Rear-facing connectors, cable ties, and adhesive edges become especially noticeable in close-range office installations.

A practical site survey should classify every view:

View levelTypical conditionRequired finish
PrimaryMain storefront or reception approachWiring should be fully concealed where possible
SecondarySide angle or normal interior circulationSmall controlled transitions may be acceptable
Close rear viewDesk, meeting room, corridor, or shop interiorRear plates, connectors, and cable routes need a finished appearance
RestrictedCeiling void, cabinet interior, locked service zoneFunctional wiring may remain visible if safely enclosed
Reflection-sensitiveOpposite glass, mirrors, polished metalHidden parts may reappear through reflection

Site photographs should be taken from all primary and close rear views. A short video walking past the intended sign location often reveals sightlines that a straight photograph misses.

The final approval should identify exactly where a visible cable is permitted. “Hide the wires as much as possible” is too vague for production. A better instruction would be: “No visible wiring from the front or rear; a maximum 30 mm color-matched transition is acceptable beside the upper-left mullion.”

Does Letter Type Change Wiring?

The channel letter construction determines how many wires leave each character, where the cables can exit, and whether another background surface is required.

Front-lit channel letters normally contain LED modules inside a metal return with an acrylic face. Each letter needs at least one low-voltage connection. Large or complex letters may use more than one circuit to control voltage drop and maintain even brightness.

Halo-lit letters introduce another requirement. The light needs an opaque or semi-opaque surface behind the letter to create a visible glow. Clear glass alone does not reflect a strong, controlled halo in the same way as a painted wall. A frosted panel, painted metal backer, opaque acrylic panel, or applied film may therefore be needed. The same background can hide wires and mounting hardware.

Front-and-halo-lit letters may contain separate front and rear LED groups. The electrical load, number of leads, letter depth, and power-supply capacity can therefore be higher than for a single-lighting system.

A simplified comparison is shown below:

Letter typeTypical wiring difficulty on clear glassMain concern
Front-litMediumIndividual leads and rear mounting hardware
Halo-litHigh without a backerGlass provides limited halo reflection and exposes rear LEDs
Front and halo-litHighMore wiring, greater depth, and separate lighting zones
Side-litHighRear and side details remain visually exposed
Letters on an opaque backerLow to mediumWiring can be concealed behind the panel
Raceway-mounted lettersMediumWiring is easier to manage, but the raceway remains visible

Letter size also matters. A small logo may have many narrow characters packed close together. The total LED load may be modest, but the number of separate leads can create clutter. A large wordmark may use fewer characters but require longer cable runs and several power circuits.

Wire exits should therefore be positioned individually. Using the same center-back exit for every letter may force unnecessary exposed cable. A letter beside a vertical mullion may need a side-oriented exit, while a central character may route directly into a horizontal wireway.

Do Frames Limit Cable Routes?

Aluminum mullions, top headers, bottom channels, and nearby ceiling cavities often provide the best opportunity to hide wiring. However, a visible frame does not automatically contain a usable cable path.

A mullion may contain:

  • Internal reinforcement
  • Drainage passages
  • Pressure plates
  • Fasteners
  • Gaskets
  • Thermal breaks
  • Fire-stopping materials
  • Factory-installed wiring
  • Barriers between horizontal and vertical sections

A cable route that looks continuous from outside may be blocked internally. Drilling into the wrong section may damage a glazing seal, interfere with drainage, or affect the curtain-wall warranty.

Before production, the local installer or glazing contractor should confirm:

  1. Which frame sections are hollow and accessible
  2. Whether the cavity connects to the ceiling, floor, or adjacent wall
  3. Where cable entry and exit holes are permitted
  4. Whether a protective conduit or grommet is needed
  5. Whether the frame contains drainage or structural components
  6. How the cable will be pulled and serviced later
  7. Whether the frame can support any sign load

Frame location also affects the logo position. Consider a 2,400 mm-wide wordmark centered on a 3,000 mm glass panel. When the only usable cable path is the right mullion, leads from the left-side letters may need to travel more than 2 metres before entering the concealed route. That distance can increase cable quantity, voltage drop, and installation time.

Several solutions may be considered:

  • Add a slim horizontal wireway behind the letters
  • Divide the sign into left and right electrical groups
  • Move the power supplies closer to the sign
  • Use a 24 V LED system when technically appropriate
  • Add an opaque backer band aligned with the frame
  • Adjust the logo position slightly to shorten the exposed route

The cleanest visual layout is not always the easiest electrical layout. A small position adjustment of 50–100 mm may produce a much shorter and less visible cable route without materially changing the branding.

Can Wiring Be Fully Invisible?

A permanently illuminated channel letter sign needs a power path. In most commercial projects, complete electrical invisibility is achieved by concealing conventional wiring rather than eliminating it.

Battery-powered letters are rarely suitable for permanent storefront or office use. A sign operating 10–14 hours per day would require regular charging or battery replacement. Battery compartments also need access, adding bulk behind the letters. Brightness can become unstable as the battery discharges.

Transparent conductors and wireless power systems exist in specialized applications, but they should not be assumed to work with standard fabricated channel letters. Load capacity, operating distance, component compatibility, certification, service life, and replacement availability all require separate verification.

A more realistic target is to make every electrical transition deliberate and short:

  • The lead exits close to a mullion, wireway, or backer
  • No cable crosses the center of a clear panel
  • Connectors remain inside an enclosure
  • Power supplies remain outside normal viewing areas
  • Cable jackets match nearby metalwork where a short section remains visible
  • Circuits are labeled and reachable for maintenance
  • Rear-facing hardware receives the same finish standard as the front

The difference between “hidden” and “unplanned” is often measured in a few centimetres. A 20–30 mm cable transition beside a dark frame may disappear during normal use. A 300 mm diagonal wire across clear glass will remain visible even when a transparent cable jacket is used.

The project team should agree on a visibility standard before production:

Visibility targetPractical meaning
Fully concealedNo cable, connector, or power component visible from approved viewing positions
Architecturally concealedWiring is hidden inside frames, backers, wireways, or raceways
Controlled transitionOnly a short, straight, color-matched cable section remains visible
Front-clean onlyWiring may be visible from the rear; suitable only where the rear cannot be seen
Service-firstEnclosures remain visible but provide fast access and reliable maintenance

For most glass-wall projects, an architecturally concealed solution provides the best balance. It delivers a clean appearance without depending on unproven wireless products or permanently sealing service components behind the glass.

Iduoduo’s engineering process treats letter structure, LED layout, power capacity, circuit grouping, wire exits, mounting holes, backboards, raceways, and installation interfaces as connected production decisions rather than separate site adjustments.

Which Concealment Methods Work?

Channel letters mounted on a slim wireway that conceals wiring on a glass storefront

Channel letter wiring can be concealed through an existing mullion, a slim wireway, a structural raceway, an opaque backer panel, or a custom hollow support. The right method depends on cable distance, letter weight, glass construction, rear visibility, power-supply access, and installation restrictions. A clean solution must hide conductors without trapping serviceable electrical parts behind permanent glass.

A concealment method should be selected only after answering five questions:

  • Where does each letter lead leave the sign?
  • How far is the nearest usable frame or service area?
  • What supports the weight of the letters?
  • Where will the power supplies and connectors remain accessible?
  • Which parts of the installation can be seen from the rear and sides?

The following comparison provides a practical starting point. The measurements are common planning ranges rather than fixed manufacturing standards.

MethodTypical visible depthStructural roleUsual power-supply positionRear appearanceBest suited to
Frame or mullion routingNo added visible enclosureUsually noneCeiling, cabinet, or nearby service areaVery clean when access is confirmedFramed glass storefronts
Slim wirewayAbout 25–75 mmMainly cable managementUsually remoteClean when aligned with the architectureInterior glass partitions and reception walls
Structural racewayAbout 75–150 mm or project-specificCan carry letters and wiringInside or remoteMore visible but orderlyProjects requiring faster installation
Opaque backer panelPanel-dependentCan support letters when engineeredBehind panel or remoteWiring can be almost fully concealedHalo-lit logos and two-sided viewing areas
Hollow rods or custom supportsProject-specificYes, when structurally designedCeiling, floor, or adjacent structureMinimal when carefully placedHigh-end architectural installations
Exposed color-matched transitionCable diameter onlyNoneRemoteVisible at close rangeShort unavoidable connections beside a frame

No option is automatically superior. A narrow wireway may look cleaner than a raceway, yet a raceway may reduce glass attachments, shorten installation time, and make future repairs easier. A backer panel may hide everything, but it also removes part of the transparency that made the glass wall attractive.

Can Wires Run Through Frames?

Existing aluminum mullions, head tracks, base channels, and adjacent metal framing often provide the least visible route. A cable can leave the letters, enter a short wireway or concealed opening, travel through the frame, and reach a ceiling cavity or nearby service enclosure.

Frame routing works particularly well when:

  • The logo sits close to a vertical mullion.
  • The frame has an accessible hollow section.
  • The cavity continues to the ceiling, floor, or adjoining wall.
  • Cable entry points are permitted by the glazing contractor.
  • The power supply can remain within a reasonable cable distance.
  • The frame is dark enough to hide a short matching cable transition.

Consider a 1,800 mm-wide illuminated logo positioned 150 mm from a black aluminum mullion. A 30–50 mm cable transition may be hidden beside the frame with little visual impact. Move the same logo to the center of a 3,000 mm clear panel, and the nearest concealed route may require more than 1,000 mm of horizontal travel. At that point, adding a slim wireway may produce a cleaner and more reliable result.

The inside of a frame must be inspected rather than assumed. Common obstructions include reinforcement, pressure plates, fasteners, thermal breaks, gaskets, drainage channels, fire-stopping, and barriers between horizontal and vertical sections.

Before approving frame routing, the local installer should verify:

Site checkRequired answer
Is the frame hollow?Confirm the exact usable cavity, not only the external profile
Is the cavity continuous?Check whether the horizontal and vertical sections connect internally
Are drainage paths present?Keep cables and sealants away from required water channels
Can a cable be pulled through?Confirm entry, exit, bend radius, and pulling access
Is conduit required?Follow the electrician’s and local code requirements
Can the frame carry sign weight?Do not assume a cable route is also a structural support
Can the cable be serviced?Avoid routes that become inaccessible after trim installation

A useful installation test is to pass a pull line through the proposed route before the letters enter production. That small site check can prevent a finished sign from arriving with wire exits designed for a frame cavity that cannot actually be used.

The production drawing should show the exact entry point and the required lead length. “Route through nearby frame” is too vague. A better instruction is: “All low-voltage leads enter the upper-right mullion at 2,250 mm above finished floor; provide 1,200 mm labeled leads from the right end of the wireway.”

When Is a Wireway Better?

A wireway is often the best compromise when individual cables cannot enter the wall or frame directly, but the project still needs a light, architectural appearance.

A wireway is normally a narrow enclosure used to collect and protect low-voltage leads. It may run behind the letters, beneath the wordmark, above the logo, or along an existing architectural line. The enclosure can be painted to match the mullion, letter returns, ceiling trim, wall finish, or brand color.

Terminology varies between sign markets. Some fabricators use “wireway” for a slim cable enclosure and “raceway” for a larger structural cabinet. The approved drawing should therefore show dimensions and internal contents rather than relying on the name alone.

A wireway is usually suitable when:

  • Letter weight is supported separately.
  • Power supplies will be installed remotely.
  • Only low-voltage conductors and connectors need concealment.
  • The logo is relatively close to a frame or service point.
  • Rear appearance needs to remain tidy.
  • A full structural raceway would look too heavy.

A common arrangement places a 40–60 mm-high horizontal wireway behind the lower or central part of the letters. Each character lead enters the enclosure immediately. A single grouped cable then exits at one end and enters the nearest mullion.

The height and depth should be based on the real contents:

  • Number of letter leads
  • Conductor size
  • Connector dimensions
  • Cable bend radius
  • Strain relief
  • Circuit labels
  • Separation requirements
  • Removable cover clearance
  • Installation tolerance

A wireway drawn at only 15–20 mm deep may look elegant in a rendering but leave no practical room for several connectors. Installers may then push joints outside the enclosure or compress wires against sharp edges.

A workable specification should answer four practical questions:

  1. Can every connector fit without stacking excessive pressure on the cover?
  2. Can a technician reopen the enclosure after installation?
  3. Can one circuit be disconnected without cutting neighboring wires?
  4. Is the exit positioned close enough to the mullion to avoid a long exposed transition?

The finish also matters. A wireway matched to black anodized framing may visually merge with the storefront. A white enclosure crossing dark glass may become more noticeable than the letters. For brushed stainless-steel letters, matching the wireway to the frame often looks cleaner than matching it to the letter face.

A removable cover should normally face a serviceable direction. Placing the cover tightly against the glass may make the enclosure impossible to reopen without removing the sign.

When Is a Raceway Needed?

A raceway becomes useful when a single fabricated structure must support the channel letters, collect the wiring, reduce site connections, and possibly contain approved power components.

Compared with individually mounted letters, a raceway can reduce installation work because the letters arrive attached to one aligned assembly. Much of the low-voltage wiring can be completed, labeled, and tested before shipment. The local installer then fixes the raceway to an approved support and completes fewer final electrical connections.

A raceway is worth considering when:

  • The glass cannot accept multiple individual letter fixings.
  • Surrounding mullions can support one engineered assembly.
  • Installation time on site is limited.
  • The logo contains many small characters and separate wire leads.
  • A chain-store program needs repeatable installation.
  • Local access behind the glass is poor.
  • A clean rear surface is more important than complete transparency.

Suppose a wordmark contains 14 separate illuminated letters. Individual installation could require 14 positioning steps, numerous fixings, and multiple cable connections. A preassembled raceway may reduce the site work to several structural attachment points and one or two labeled electrical feeds. Actual fixing quantities still depend on weight, span, support conditions, and engineering review.

The main drawback is visual mass. A raceway may look like a large horizontal box when viewed through clear glass. Several design choices can reduce the impact:

  • Match its finish to the storefront framing.
  • Align its height with a nearby door header or transom.
  • Keep the raceway within the overall logo width.
  • Avoid extending far beyond the first and last letters.
  • Use a darker recess behind the letters to reduce perceived depth.
  • Position it where the logo naturally forms a strong horizontal line.
  • Use a shaped or stepped profile rather than an oversized rectangular cabinet.

Power supplies may be placed inside only when the raceway provides enough room, ventilation, separation, access, and compliance with the project requirements. A smaller raceway with remote power supplies may look better than enlarging the enclosure solely to hold electrical equipment.

Service access should be tested during design. A removable panel is of little value when the glass, ceiling, or neighboring letters prevent it from opening. Confirm the access direction, screw positions, tool clearance, and replacement space around every power supply.

A simple planning comparison helps determine whether the added depth is justified:

Project conditionIndividual or wireway mountingRaceway mounting
3–5 large lettersOften practicalMay look unnecessarily heavy
10–20 small lettersMany separate leads and fixing pointsOften reduces installation work
Rear view is highly visibleHardware may be difficult to finish cleanlyOne controlled rear structure
Transparency must remain dominantUsually betterMay cover too much glass
Installation window is shortMore site workMore work completed in the factory
Power supply must stay remoteEasy to arrangeRaceway can remain relatively slim
Power supply must be near lettersSeparate enclosure may be neededPossible inside an accessible raceway

Iduoduo treats the raceway, backboard, mounting holes, wire exits, power system, and installation method as connected project specifications. Those details are recorded with the final drawings for production and repeat orders.

Can a Backer Panel Hide More?

An opaque or semi-opaque backer panel can hide nearly all wiring, connectors, studs, and rear construction. It also creates a stable visual background when changing views through the glass make the logo difficult to read.

Common backer materials include:

  • Painted aluminum sheet
  • Aluminum composite panel
  • Opaque acrylic
  • Frosted acrylic
  • Printed architectural panel
  • Powder-coated metal frame with an infill panel
  • Applied film combined with a concealed support system

A backer panel is particularly useful for halo-lit letters. Halo illumination needs a surface to receive the rear light. Clear glass alone usually produces a weak and uncontrolled glow. A white, light-gray, frosted, or brand-colored backer can improve halo definition while concealing the electrical system.

Backer design can follow several forms:

Backer styleVisual resultWiring capacityCommon use
Full rectangular panelStrong background, least transparencyHighReception walls and retail interiors
Narrow horizontal bandRetains more glassMedium to highLong wordmarks
Logo-shaped panelIntegrated appearanceMediumCompact logos and feature walls
Frosted translucent panelSofter visual separationMediumOffices and hospitality interiors
Double-panel constructionFinished from both sidesHighGlass partitions visible from front and rear

Panel size should not be based only on the logo outline. Space is also needed for cable bends, connectors, fasteners, panel edge returns, and service openings. A panel extending 50–100 mm beyond the sign may provide enough room for concealed wiring, but actual margins depend on letter depth and construction.

The rear view deserves the same care as the front. A front-facing aluminum panel with exposed nuts and cable bundles behind it solves only half the problem. Where both sides are visible, a second finishing panel or boxed backer may be needed. Removable rear access can allow maintenance without disturbing the letters.

Important checks include:

  • Panel weight and deflection
  • Supporting frame capacity
  • Thermal expansion
  • Edge finish
  • Reflection on the glass
  • Mounting clearance
  • Power-supply ventilation
  • Removable service areas
  • Rear-side finish
  • Relationship between panel color and halo brightness

A backer can also improve logo contrast during daylight. Dark letters installed directly on glass may disappear against dark interior areas, while light letters may lose definition against bright outdoor views. A controlled background keeps the brand readable regardless of activity behind the glass.

The trade-off is clear: better concealment and readability in exchange for less transparency. A small full-size mock-up or printed elevation on the glass helps determine whether the panel feels intentional or overly dominant.

Are Wireless Systems Practical?

A commercial channel letter set still requires a dependable power path. Products promoted as “wireless” usually conceal the conductors rather than operate without electrical connections.

Battery-powered letters are rarely practical for permanent storefront or workplace use. A basic operating estimate shows why.

Suppose a small logo requires 48 W and operates for 12 hours per day:

48 W × 12 hours = 576 Wh per day

After allowing for conversion losses and usable battery capacity, the required battery would be considerably larger than a small concealed pack. Daily charging or frequent battery replacement would also create a maintenance burden. A larger sign drawing 150 W would require:

150 W × 12 hours = 1,800 Wh per day

Such energy demand makes conventional mains-powered supplies and concealed low-voltage wiring far more practical.

Specialized conductive films, transparent busbars, magnetic contacts, or inductive systems may suit limited display products. They are not interchangeable with standard channel letter construction. Before considering one, verify:

  • Supported voltage and current
  • Maximum transmission distance
  • Visible conductor pattern
  • Heat generation
  • Compatibility with the glass coating
  • Product certification
  • Replacement-part availability
  • Dimming or control compatibility
  • Expected operating life
  • Access after installation

A proven 12 V or 24 V cable hidden in a frame is usually easier to install, test, repair, and replace than an uncommon power-transfer system. The better goal is not “no wire”; it is “no visually distracting wire.”

When a short exposed transition cannot be avoided, improve the result by controlling every detail:

  • Keep the transition as short as possible.
  • Route it parallel to a mullion or panel edge.
  • Avoid diagonal cable runs.
  • Match the jacket color to the nearby structure.
  • Remove visible cable printing where the approved wire specification allows.
  • Place connectors inside an enclosure rather than on the glass.
  • Use grommets where the cable passes through metal.
  • Secure the cable so it does not sag or move during cleaning.
  • Record the accepted visible length on the drawing.

A straight 20–30 mm black transition beside a black mullion may be barely noticeable from normal viewing distance. A 250 mm loop across clear glass will remain obvious regardless of cable color.

The final choice should prioritize reliability, access, and visual control in that order. An installation that looks completely wire-free on opening day but requires glass removal for the first power-supply replacement is not a well-hidden system. It is an inaccessible one.

Iduoduo’s documented engineering process includes power matching, line grouping, wire-exit planning, raceway or backboard preparation, mounting interfaces, and installation coordination. Low-voltage planning also covers 12 V or 24 V matching, polarity, conductor length, voltage drop, connectors, circuit identification, and service position.

How Should Power Be Routed?

Channel letter power cables routed through a mullion to an accessible ceiling power supply

Power should follow a planned path from the building supply to an accessible power supply, then through labeled low-voltage circuits to the channel letters. On glass walls, mains-voltage equipment should normally remain in a ceiling, cabinet, raceway, or approved service enclosure. Only the shortest practical low-voltage transition should approach the visible glass area.

A workable power plan should show the complete route:

Building circuit → switch or control → power supply → low-voltage circuit groups → concealed wireway or frame → individual letters

Leaving any part of the route undefined often creates exposed cables, overloaded power supplies, uneven brightness, or electrical equipment that cannot be reached after installation.

Where Should Power Supplies Go?

The best power-supply location is not always the position closest to the letters. It should provide a reasonable cable distance while remaining dry, ventilated, identifiable, and accessible for testing or replacement.

Common locations include:

  • An accessible ceiling space above the glass
  • A nearby electrical or communications cabinet
  • Removable millwork beside the glass wall
  • An accessible section of a structural raceway
  • A service box hidden behind an opaque backer
  • A utility space on the opposite side of an adjoining wall
  • A removable header above the glass partition

A power supply should not be sealed permanently between glass panels, buried behind fixed decorative finishes, or placed where replacing it requires removal of the entire sign.

A practical location needs to satisfy all of the following:

CheckWhat should be confirmed
AccessA technician can reach and remove the unit with ordinary tools
VentilationHeat can escape according to the power-supply instructions
Moisture protectionThe location matches the indoor or outdoor rating
Cable distanceThe low-voltage run is short enough to control voltage drop
Mains connectionA local electrician can complete the approved input connection
IdentificationEach unit and output circuit can be labeled
Replacement spaceA replacement unit can pass through the access opening
Control accessDimmers, RGB controllers, receivers, and switches remain reachable
NoiseThe unit is not placed where electrical noise or vibration may disturb an office
AppearanceNo power equipment is visible through the glass from normal positions

A common mistake is placing the power supply directly behind the middle of the logo because the distance appears shortest. On a transparent wall, the unit, cables, and mounting plate may then be visible from both sides. Moving it into a ceiling or cabinet usually improves appearance, even when the low-voltage leads become slightly longer.

Distance still has limits. A remote unit located 15 metres from a 12 V sign may require larger conductors, more circuits, or a different electrical layout. Moving equipment farther away without recalculating the circuit can lead to dim letters or color differences.

Power supplies should also be grouped logically. For example, a long wordmark may use one unit for the left section and another for the right section. A front-and-halo-lit sign may use separate supplies or circuit groups for the two lighting functions. Separate grouping simplifies dimming, testing, and fault diagnosis.

A useful power-supply schedule can look like the following:

Supply IDLighting areaLED loadRated capacityOutputInstallation location
PS-01Letters A–F72 W100 W24 V DCUpper ceiling access
PS-02Letters G–L68 W100 W24 V DCUpper ceiling access
PS-03Halo lighting45 W60 W24 V DCRemovable cabinet
CTRL-01Dimming controlCompatible with 24 V systemRemovable cabinet

The ratings above are only an example. The actual supply must match the LED type, load, destination-market requirements, installation environment, and control equipment.

Iduoduo configures illuminated signs according to LED load, 12 V or 24 V operation, wiring length, voltage drop, control requirements, installation conditions, and destination-market input voltage. Project records may include power-supply model, rated wattage, quantity, circuit grouping, wire type, wiring diagram, and test results.

How Are Letter Leads Grouped?

Every illuminated letter needs a connection, but every lead should not travel independently to the power supply. A ten-letter logo with two leads per character can quickly create twenty loose conductors behind the glass.

A cleaner system divides the sign into planned circuit groups. Leads from nearby letters enter a wireway, raceway, backer panel, mullion, or junction enclosure. The grouped circuit then continues toward the power supply.

Circuit groups can be based on:

  • Physical position
  • Connected wattage
  • Power-supply capacity
  • Cable length
  • Front or halo illumination
  • Dimming zone
  • RGB or RGBW control channel
  • Service area
  • Sign section or shipping section

For a 2,400 mm-wide wordmark, a practical layout might divide the letters into left, center, and right groups. Each group receives a dedicated two-conductor feed. The arrangement avoids carrying the total current through one long cable and makes it easier to locate a fault.

The following example shows how a 12-letter sign may be divided:

CircuitLettersEstimated loadRoutePower source
A1–442 WLeft end to left mullionPS-01
B5–846 WCenter wireway to left mullionPS-01
C9–1244 WRight end to right mullionPS-02
DRear halo58 WBacker cavity to right mullionPS-03

Circuit labels should appear in four places:

  • On the production drawing
  • On the cable near the letter group
  • At the power-supply output
  • On the installation or wiring instructions

Simple labels such as A+, A−, B+, and B− help prevent reversed polarity and incorrect grouping. For multi-store projects, labels should also include the store or project number.

Daisy-chaining every letter in one long series-like route should generally be avoided unless the LED system is specifically designed for that arrangement. Although the modules may still be electrically connected in parallel, carrying the feed through a long sequence of small links can create unequal conductor lengths, more connection points, and harder troubleshooting.

A better pattern uses balanced branches:

Power supply → distribution point → separate branches to letter groups

Balanced does not mean every branch must be identical. It means the loads and cable lengths have been considered rather than connected in the order most convenient during installation.

Connector position matters as much as circuit grouping. Connections should remain:

  • Inside a wireway, raceway, backer, or approved enclosure
  • Protected from sharp metal edges
  • Accessible where future testing may be needed
  • Rated for the circuit current and environment
  • Secured against pulling or vibration
  • Separated from visible glass areas
  • Clearly marked for polarity

Connectors should not hang behind individual letters where they remain visible through the glass. Uncontrolled splices also make later fault diagnosis much slower.

Lead length should be specified on the drawing. A cable that is 100 mm too short may force an exposed site splice. A cable that is 2 metres too long may be coiled inside a narrow wireway, filling the service space and making circuit identification difficult.

The project team should provide route measurements instead of asking the factory to “leave long wires.” Useful measurements include:

  • Letter exit to wireway
  • Wireway length
  • Wireway to mullion
  • Mullion to ceiling
  • Ceiling entry to power supply
  • Power supply to control equipment
  • Required service loop at each accessible point

A modest service loop near an accessible connection can help installation and maintenance. Large loose coils behind the glass do not.

Does Voltage Drop Affect Routing?

Voltage drop has a direct effect on brightness, color stability, and circuit reliability. It is especially important for low-voltage channel letters because even a small loss can represent a meaningful percentage of a 12 V or 24 V system.

Voltage drop is determined by:

  • Circuit current
  • One-way cable length
  • Return cable length
  • Conductor size
  • Conductor material
  • Connector resistance
  • Number of splices
  • Operating temperature
  • Quality of the terminals

The basic relationship is:

Voltage drop = Current × Total circuit resistance

Total circuit resistance includes both the outgoing and return conductors. A route described as “10 metres from the power supply” normally has approximately 20 metres of conductor path in a two-wire circuit.

The effect becomes easier to understand with a simple comparison. Assume a 120 W sign and the same cable resistance for both systems:

SystemApproximate currentExample voltage lossPercentage loss
12 V, 120 W10 A1.0 V8.3%
24 V, 120 W5 A0.5 V2.1%

The values are illustrative, but the principle is important. At the same wattage, a 24 V system draws roughly half the current of a 12 V system. Lower current reduces voltage loss in the same conductor. The percentage effect is also smaller because the operating voltage is higher.

A 24 V system is not automatically better for every sign. The LED modules, controllers, dimmers, power supplies, and wiring must all be designed for the same voltage. Mixing 12 V and 24 V parts can damage equipment.

Signs of excessive voltage drop include:

  • Letters at the far end appear dimmer
  • White LEDs develop a slight color difference
  • RGB or RGBW colors become inconsistent
  • Brightness changes when more letters are connected
  • The power supply output is correct, but voltage at the letters is low
  • Connectors or undersized cables become warm
  • One branch flickers during startup or dimming

A voltage-drop problem should not be corrected by turning up an adjustable power supply without checking component limits. Increasing output voltage may overdrive letters close to the supply while only partly correcting the distant group.

Better solutions include:

  • Shortening the low-voltage route
  • Moving the power supply closer
  • Dividing one large group into two or more branches
  • Increasing conductor size
  • Reducing the number of unnecessary connectors
  • Feeding a long sign from both ends where the electrical design permits
  • Using a compatible 24 V LED system
  • Installing separate supplies for distant sign sections
  • Checking every connection for resistance

The power-supply capacity also needs an operating margin. A common planning practice is to keep the connected load below roughly 80% of the rated output, provided the component manufacturer and local requirements support that approach.

For example:

Calculated LED load: 96 W
Planning factor: 80% maximum loading
Minimum supply rating: 96 W ÷ 0.80 = 120 W

A 120 W supply would therefore be a reasonable starting point. A smaller 100 W unit would operate too close to its full rating under that planning method.

The load should be calculated from actual approved LEDs rather than estimated only from letter size. Two 600 mm-high letters can have different wattages because of stroke width, module spacing, illumination type, and internal geometry.

A useful calculation sheet should record:

Electrical itemRequired information
LED modelRated voltage and wattage per module or metre
Module quantityCount for every letter or sign section
Calculated loadTotal connected wattage
Supply capacityRated output wattage and current
Load percentageCalculated load divided by rated capacity
Cable routeComplete one-way distance
ConductorSize, type, insulation, and rating
Estimated dropCalculated under expected operating load
Measured voltageAt supply and farthest letter
Control loadDimmers and controllers included where applicable

Final conductor sizing and acceptable voltage drop should be confirmed against the LED supplier’s requirements, the power-supply instructions, and the applicable local electrical rules.

Which Parts Need Service Access?

A hidden electrical system still needs a repair path. Power supplies, dimmers, controllers, receivers, connectors, and distribution points may eventually require inspection or replacement.

A project can look clean on opening day and become expensive to maintain when the first power supply fails. Service planning should therefore begin before the letters are produced.

Parts that normally need access include:

  • Power supplies
  • AC input terminals
  • Low-voltage output terminals
  • Dimmers
  • RGB and RGBW controllers
  • Wireless control receivers
  • Distribution blocks
  • Fuses where specified
  • Main cable connectors
  • Raceway covers
  • Backer-panel access covers
  • Junction enclosures
  • Removable letter backs or faces where applicable

Accessibility should be checked physically, not only shown as a small rectangle on a drawing.

Ask the following questions:

  • Can the access panel open fully?
  • Is there room for a screwdriver or driver?
  • Can the power supply pass through the opening?
  • Can its label be read without removing other parts?
  • Can voltage be measured while the circuit is operating?
  • Can one output branch be disconnected independently?
  • Are terminal screws facing the service side?
  • Does a ceiling grid block removal?
  • Does the glass prevent a raceway cover from sliding away?
  • Can the area be reached without special glazing removal?
  • Is a ladder or lift required, and is there room to position it?

A common error is installing the power supply inside a narrow raceway with a removable cover facing the glass. Once the raceway is mounted close to the panel, the cover cannot be removed. The power supply is technically inside a “serviceable enclosure” but cannot actually be serviced.

The access direction should be drawn in section:

ComponentPreferred accessImportant check
Ceiling-mounted supplyFrom removable ceiling tileReplacement unit fits through opening
Raceway supplyFront, top, or bottom removable coverGlass does not block cover movement
Backer-panel supplyRemovable rear or side panelRear viewing area remains finished
Cabinet supplyThrough cabinet doorVentilation remains open
ControllerNear supply or accessible control pointPairing and reset controls can be reached
Distribution connectorInside removable wirewayIndividual circuit can be tested

Service labels should remain permanent and readable. A simple circuit directory can reduce diagnostic time:

PS-01: Letters A–F
PS-02: Letters G–L
PS-03: Halo lighting
CTRL-01: Dimming
Circuit A: Left word section
Circuit B: Center word section
Circuit C: Right word section

During fault diagnosis, the installer should not need to guess which supply controls which letters.

A glass installation should also allow limited product removal. When one letter needs attention, removing it should not require dismantling the entire backer or disconnecting every circuit. Numbered letters, templates, labeled leads, and accessible connectors make localized repair possible.

Iduoduo’s installation documentation emphasizes retaining access to power supplies, controllers, removable panels, raceway covers, wiring routes, drainage points, and fastening inspections after installation.

Do Local Codes Change the Plan?

Local electrical and building requirements can change the power-supply model, input connection, cable type, enclosure, grounding, disconnect method, and installer responsibilities.

The sign factory can prepare a compatible low-voltage system, but the building-side connection must be reviewed at the destination.

Items that may vary by country, state, city, landlord, or project include:

  • Building input voltage
  • 50 Hz or 60 Hz frequency
  • Plug or hardwired connection
  • Power-supply certification
  • Complete-sign certification
  • Cable insulation requirements
  • Conduit requirements
  • Junction-box type
  • Grounding or bonding
  • Disconnect location
  • Circuit protection
  • Fire-rated wall or ceiling penetrations
  • Separation between mains and low-voltage conductors
  • Emergency power restrictions
  • Shopping-center electrical rules
  • Permit and inspection requirements

Iduoduo can configure power supplies for 110–240 V input markets and prepare 12 V or 24 V low-voltage sign systems. However, a certified power supply does not automatically make the complete sign certified for every jurisdiction. Building circuits, breakers, grounding, mains wiring, permits, and final inspection remain local responsibilities.

The division of work should be written clearly:

Work itemFactory roleLocal project role
LED selectionMatch sign construction and lighting requirementReview any site-specific restrictions
Power-supply selectionMatch load, output voltage, environment, and requested certificationConfirm acceptance by local authority
Low-voltage wire exitsProduce according to approved drawingRoute and connect on site
Wiring diagramProvide circuit and polarity informationVerify against site conditions
Building circuitNot supplied unless specifically agreedLicensed electrician provides and confirms
AC hardwiringProduct interface may be preparedQualified local electrician completes
Grounding and bondingProduct parts prepared where applicableLocal electrician completes and verifies
Glass or frame penetrationShown on mounting drawingsGlazier and installer approve and perform
Permit and inspectionTechnical information may be suppliedLocal project team obtains approval
Final commissioningFactory tests the product before shipmentLocal team verifies installed system

The site should also confirm how the sign will be controlled. Possible arrangements include:

  • Dedicated wall switch
  • Time clock
  • Photocell
  • Building-management system
  • Dimmable driver
  • Remote dimmer
  • RGB or RGBW controller
  • App-based control
  • Central control for several signs

Control compatibility must be checked before production. A standard non-dimmable power supply should not be connected to a phase-cut dimmer unless the equipment specifically supports it. RGB and RGBW systems require compatible controllers, amplifiers where needed, correct cable grouping, and a reachable location for pairing or reset.

Glass frames should not be used automatically as electrical conduits. The glazier and electrician need to confirm whether a cavity can accept cable, whether drainage paths remain open, and whether additional protection is required.

A useful pre-production electrical checklist includes:

  • Destination country and installation address
  • Building input voltage and frequency
  • Plug or hardwired connection
  • Indoor or outdoor location
  • 12 V or 24 V LED system
  • Total LED load
  • Power-supply number and capacity
  • Required certification or documentation
  • Power-supply mounting position
  • Complete low-voltage route length
  • Wireway, raceway, backer, or mullion route
  • Circuit grouping
  • Conductor requirements
  • Dimming or color control
  • Switching method
  • Service-access direction
  • Local electrician contact
  • Glazing or frame restrictions
  • Approval drawing version

Before shipment, the complete sign should be checked for correct voltage, polarity, circuit grouping, power-supply stability, connector condition, illumination, flicker, color consistency, and abnormal heat. Iduoduo records electrical data where required and performs a 100% lighting check followed by 72-hour pre-shipment testing on illuminated products, including observation of wiring, supplies, controllers, flicker, temperature, and early failure.

What Should Be Confirmed Before Production?

Clean channel letter mounting on glass with concealed fixings and accurately aligned letters

Production should not begin until the glass construction, finished sign size, viewing directions, mounting method, cable route, power location, service access, electrical requirements, and approved drawing version all agree. For glass-wall channel letters, a visually correct rendering is not enough. The factory needs measurable site information that can be converted into wire exits, mounting holes, circuit groups, lead lengths, backer dimensions, and installation parts.

Most installation problems do not begin on the production floor. They begin with one missing site measurement or an assumption such as:

  • “The mullion should be hollow.”
  • “The electrician can find somewhere for the power supply.”
  • “The rear wiring will not be noticeable.”
  • “The glass can probably be drilled.”
  • “Long wires can be shortened during installation.”
  • “The logo position can be adjusted on site.”

Each statement leaves an unresolved decision for the installer. On clear glass, even a small change can affect the entire arrangement. Moving a logo 80 mm may change its relationship with a mullion. Changing the power location may add several metres of low-voltage cable. Adding a backer may change the letter standoff, halo effect, weight, and attachment method.

A practical production release should confirm five groups of information:

Confirmation groupMain items
Site conditionsGlass type, panel dimensions, frames, ceiling, floor, nearby walls and access
Sign appearanceLogo size, position, color, lighting method, front view, rear view and side view
MountingSupport structure, attachment points, backer or raceway, hole positions and template
ElectricalInput voltage, LED voltage, power supplies, controls, wire exits, cable route and service access
Production controlApproved drawings, material schedule, finish schedule, BOM, revision number and approval date

A useful rule is that every item affecting production should appear in an approved drawing or specification. Important decisions should not remain only in email messages, marked-up screenshots, or separate chat conversations.

Which Site Photos Are Needed?

A single front-facing photo rarely provides enough information for channel letters on glass. The sign may look correct in the photograph while the ceiling access, rear viewing area, glass joints, mullion depth, and power route remain unknown.

For a straightforward installation, collect at least 8–12 clear site photographs. A more complex storefront or glass partition may need 15–25 images plus a short walkthrough video.

The photograph set should cover:

  1. The complete glass elevation
  2. A straight front view of the proposed sign area
  3. A rear view from inside the space
  4. A left-angle view
  5. A right-angle view
  6. A view looking upward toward the ceiling
  7. A view looking downward toward the floor channel
  8. Close views of vertical mullions
  9. Close views of horizontal frames or transoms
  10. The nearest electrical access point
  11. Any cabinet, ceiling hatch, wall cavity, or service space
  12. Nearby doors, handles, sprinklers, sensors, cameras, lights, or air outlets

The photographs should show more than the exact logo area. A wider image helps reveal architectural lines that may influence the mounting or cable route. For example, a vertical mullion 600 mm outside the proposed logo area may provide the only practical route to the ceiling.

A close photograph should include a ruler or tape measure wherever possible. Useful measured views include:

  • Visible mullion width
  • Frame depth
  • Distance from glass edge to mullion centerline
  • Ceiling height
  • Floor-to-logo height
  • Distance to the nearest access panel
  • Distance to the proposed power-supply position
  • Size of any removable ceiling tile
  • Clearance behind an opaque panel or cabinet

Photographs should be taken square to the surface rather than from an extreme angle. Perspective distortion can make a 2,000 mm glass panel appear much wider or narrower than its real size.

A good photograph file name also saves time. Instead of sending files called IMG_4671 and IMG_4672, use names such as:

  • Front-overall
  • Rear-overall
  • Left-mullion
  • Right-mullion
  • Ceiling-access
  • Power-location
  • Glass-label
  • Proposed-logo-position

For projects where the rear side remains visible, photograph the rear area at normal eye level. The view from a meeting table, reception desk, corridor, or retail counter may be more important than a photograph taken while standing directly behind the letters.

Lighting conditions also matter. Take photographs during normal daytime use and, where possible, after dark. Dark cable jackets may disappear against a night background but become obvious in daylight. Reflections may reveal hardware that is difficult to see in a direct photograph.

A short video should begin several metres away, approach the sign location, move past both sides, show the rear, then continue upward to the proposed cable and power route. A 30–60 second video often reveals:

  • Which views are most noticeable
  • Whether the glass belongs to a door or fixed panel
  • How people move around the sign
  • Whether ceiling access is practical
  • Whether the frame connects continuously to the ceiling
  • Whether a backer would block an important sightline

The site photograph package should also include one marked image. The proposed sign outline can be drawn over the photo with:

  • Overall width
  • Overall height
  • Centerline
  • Distance from finished floor
  • Distance to nearby frames
  • Intended cable exit direction
  • Proposed power-supply area

The factory should not scale the sign from a photograph alone. At least one verified horizontal measurement and one verified vertical measurement are needed. For better accuracy, provide the actual glass panel width, glass panel height, mullion spacing, and finished-floor reference.

The following checklist can be sent to the site surveyor:

Photo or measurementMinimum information required
Full elevationEntire glass panel and surrounding construction
Front viewProposed sign position with a known dimension
Rear viewHardware and wiring visibility from inside
Side viewsLetter depth and possible exposed cables
Mullion close-upWidth, depth, joint, cover and access
Ceiling viewHeader, ceiling void and access panel
Floor viewBase channel and any floor service route
Power areaOutlet, junction point, switch or cabinet
ObstructionsDoors, lighting, sensors, sprinklers and furniture
Glass identificationLabel, drawing, specification or fabricator information

When site access is limited, ask the local installer to make a quick dimension sketch. A rough sketch with accurate measurements is more useful than an attractive photograph with no scale.

What Glass Details Matter?

“Glass wall” is not a complete material specification. Tempered glass, laminated glass, insulated glass, coated glass, curved glass, fire-rated glass, and framed glass partitions have different limitations.

Before production, confirm:

  • Glass type
  • Glass thickness
  • Panel width and height
  • Whether the panel is tempered
  • Whether the panel is laminated
  • Whether it is a single or insulated unit
  • Whether coatings or films are present
  • Whether the glass is clear, tinted, frosted, or printed
  • Whether the panel already exists
  • Whether holes were prepared before tempering
  • Whether the glass edge is exposed
  • Whether the frame is structural or decorative
  • Whether the glazier permits bonding, clamping, or drilling
  • Whether the glass carries a manufacturer’s warranty

Glass thickness alone does not confirm whether a sign can be attached. A 12 mm panel may still be unsuitable for a proposed fixing because of edge conditions, unsupported span, existing holes, coating, glass type, or load direction.

The most useful information comes from the glass fabricator, glazier, façade drawing, or partition-system specification. A verbal statement such as “It is strong commercial glass” is not sufficient for selecting hardware.

The project should establish whether the glass has already been produced.

For new glass that has not yet been tempered, the project may still coordinate:

  • Factory-made holes
  • Hole diameters and center positions
  • Edge distances
  • Concealed support plates
  • Frosted films
  • Opaque printing
  • Wire-entry openings
  • Through-bolt locations
  • Alignment with structural framing

For existing tempered glass, the practical options may be limited to:

  • Existing frame attachment
  • Raceway attachment to surrounding structure
  • Backer panel supported independently of the glass
  • Approved adhesive systems
  • Approved clamps
  • Ceiling- or floor-supported frames
  • Existing factory-made holes

No drilling instruction should be issued until the glass fabricator or qualified local professional confirms it. Finished tempered glass should not be treated like acrylic or sheet metal.

Where through-glass hardware is already planned, record:

  • Hole diameter
  • Hole center coordinates
  • Distance from each hole to the nearest edge
  • Hardware diameter
  • Sleeve or bushing dimensions
  • Washer and gasket arrangement
  • Maximum tightening method
  • Required installation tolerance
  • Glass fabricator’s approval

A small difference between the drawing and finished glass can make through-fixing impossible. For example, a sign plate with rigid studs may not fit when two holes differ by only a few millimetres. Slotted mounting plates, controlled tolerances, or adjustable brackets may be needed.

Glass coatings and films also need attention. A surface may include:

  • Low-emissivity coating
  • Privacy film
  • Decorative film
  • Security film
  • Anti-glare treatment
  • Printed ceramic pattern
  • Tint
  • Protective coating

An adhesive approved for untreated glass may not be approved for a coated or filmed surface. Bond strength may depend on whether the adhesive contacts the glass or only the film. A clear adhesive can also remain visible as a darker or glossier area.

The frame system should be recorded separately from the glass. Relevant details include:

Frame detailReason for confirmation
MaterialAffects drilling, corrosion, finish matching and grounding review
Visible face widthDetermines how well a cable transition can be hidden
Internal cavityMay provide a concealed cable route
ReinforcementMay block cable pulling or require different drilling tools
Drainage systemMust remain open and undamaged
Thermal breakMay divide the cavity internally
Removable coverMay create service access
Connection to ceilingDetermines whether wiring can continue upward
Structural capacityDetermines whether the frame can support the sign assembly

When the proposed concealment method depends on a frame cavity, ask the site team to confirm access physically. Removing one cover or passing a pull line through the route is better than assuming the cavity is continuous.

Rear visibility should also be classified before selecting the mounting method:

Rear conditionRecommended planning level
Rear completely concealedFunctional rear construction may be acceptable
Rear visible from 3–5 mCables and hardware should be orderly and color matched
Rear visible from 1–3 mUse finished covers, enclosed wiring and controlled fasteners
Rear visible within 1 mConsider a double-finished backer or boxed enclosure
Rear is a primary public viewTreat both sides as finished elevations

The glass information should be written into the project record rather than left as a site assumption. Iduoduo’s production preparation process uses storefront photographs, measurements, architectural information, installation requirements, shop drawings, sections, mounting drawings, and approved production versions to convert site conditions into manufacturable sign specifications.

Where Is Power Available?

“Power nearby” does not answer the electrical questions needed for production. The power location must be measured, identified, and connected to a defined cable route.

Confirm the following building-side information:

  • Country and installation city
  • Nominal input voltage
  • Frequency
  • Dedicated circuit or shared circuit
  • Plug-in or hardwired connection
  • Circuit switch location
  • Breaker availability
  • Control method
  • Dimming requirement
  • Daily operating schedule
  • Indoor or outdoor power-supply location
  • Distance from the power supply to the sign
  • Access for installation and replacement
  • Local electrician’s responsibility

A useful site drawing should mark three different points:

  1. Building power point
  2. Power-supply location
  3. Low-voltage entry point to the sign

Those points are often not in the same place.

For example, the building junction may be above the ceiling, while the power supply is placed inside an accessible cabinet, and the low-voltage wires enter the sign through a right-side mullion. Showing only the building junction leaves the remaining route unresolved.

Measure the complete route in sections:

Route sectionExample measurement
Power supply to ceiling entry1.2 m
Ceiling entry to mullion2.8 m
Down through mullion1.6 m
Mullion to wireway0.15 m
Wireway to farthest letter group1.9 m
Service allowance0.3 m
Total one-way route7.95 m

The electrical calculation must account for both outgoing and return conductors. A 7.95 m one-way route creates roughly 15.9 m of conductor path in a basic two-wire circuit.

The factory also needs to know whether the sign will use:

  • 12 V DC
  • 24 V DC
  • Single-color lighting
  • Tunable white
  • Dimming
  • RGB
  • RGBW
  • Separate front and halo circuits
  • One switching zone or several zones

The control method affects the number of wires and the required access. A simple single-color sign may use two conductors per circuit. RGB or RGBW lighting may require controllers, additional conductors, signal paths, amplifiers, or separate power distribution.

For each power supply, record:

  • Identification number
  • Input rating
  • Output voltage
  • Rated wattage
  • Assigned letters
  • Calculated LED load
  • Planned loading percentage
  • Installation location
  • Access direction
  • Certification requirement
  • Environmental rating
  • Control relationship

A typical schedule might read:

IDSign sectionCalculated loadSupply ratingOutputLocation
PS-01Left letters64 W100 W24 V DCCeiling access A
PS-02Right letters71 W100 W24 V DCCeiling access A
PS-03Rear halo48 W60 W24 V DCSide cabinet
CTRL-01DimmingCompatible systemSide cabinet

Those figures are examples, not fixed requirements. The final ratings depend on the approved LED system and electrical design.

Service access should be checked with actual dimensions. Record:

  • Access opening width and height
  • Clearance around the power supply
  • Cover-removal direction
  • Tool clearance
  • Ventilation openings
  • Replacement path
  • Distance from a ladder or service floor
  • Whether furniture or ceiling systems block access

An access opening may look adequate on a drawing while still being too small for the selected power supply. The replacement unit must fit through the opening without removing glass, millwork, or nearby letters.

Also confirm what happens after installation. A facilities technician should be able to identify the circuits without guessing. Labels can follow a simple format:

  • PS-01: Letters A–E
  • PS-02: Letters F–J
  • CIR-A: Left word section
  • CIR-B: Right word section
  • CTRL-01: Dimming
  • SITE-03: Main reception logo

For multiple stores, add the location or store number. The same label should appear on the drawing, wire, supply, and packing list.

Before production release, ask the local electrician to confirm:

  • Input voltage and frequency
  • Hardwire or plug connection
  • Acceptable power-supply certification
  • Cable type
  • Conduit needs
  • Junction enclosure
  • grounding or bonding requirements
  • Switching and dimming compatibility
  • Disconnect requirements
  • Local inspection responsibility

A certified component does not automatically approve the entire installed sign in every jurisdiction. Local regulated work remains the responsibility of the qualified local team.

Which Drawings Need Approval?

A rendering shows how the sign may look. It does not fully define how the sign will be manufactured, wired, attached, installed, or serviced.

For channel letters on glass, the approval set should normally include at least five drawings:

  1. Front elevation
  2. Side section
  3. Rear elevation
  4. Mounting drawing
  5. Electrical drawing

Complex projects may also need:

  • Backer-panel fabrication drawing
  • Raceway drawing
  • Wireway drawing
  • Glass-hole drawing
  • Full-size installation template
  • Power-supply schedule
  • Finish schedule
  • Bill of materials
  • Packing layout
  • Site-interface drawing

The front elevation should show:

  • Overall sign width and height
  • Individual letter heights
  • Logo proportions
  • Spacing between characters
  • Sign centerline
  • Position relative to glass edges and mullions
  • Distance above finished floor
  • Face colors
  • Return colors
  • Lighting method
  • Visible backer or raceway dimensions

The drawing should use dimensions, not only a visual scale. Statements such as “center on glass” can create disagreement when the glass panel, storefront opening, and interior sightline have different centers.

The side section should show:

  • Glass thickness
  • Frame or panel position
  • Letter depth
  • Standoff distance
  • Backer thickness
  • Raceway or wireway depth
  • Mounting hardware
  • Wire-exit point
  • Halo-lighting gap
  • Service cover
  • Clearances around the sign

For halo-lit letters, the section is especially important. The visual result depends on the distance between the rear LEDs and the receiving surface. Clear glass may require a frosted or opaque surface to create a usable halo. The drawing should show the actual receiving surface rather than displaying a halo effect against empty space.

The rear elevation should show what will remain visible through the glass:

  • Rear plates
  • Mounting studs
  • Backer edges
  • Raceway covers
  • Wireway
  • Cable transitions
  • Connectors
  • Fasteners
  • Frame entries
  • Access covers

Many installation problems remain hidden in the front elevation. A rear drawing forces the project team to decide whether each cable and fixing will be concealed, enclosed, color matched, or accepted as visible.

The mounting drawing should include:

  • Mounting method
  • Number and location of attachment points
  • Support structure
  • Hardware type
  • Hole diameters
  • Hole coordinates
  • Backer or raceway connection
  • Template reference
  • Installation sequence
  • Site-supplied parts
  • Factory-supplied parts
  • Glazier or engineer approval items

The electrical drawing should show:

  • LED operating voltage
  • Power-supply IDs
  • Power-supply ratings
  • Circuit groups
  • Letter-to-circuit assignment
  • Polarity
  • Wire exits
  • Cable entry points
  • Wireway or frame route
  • Connector locations
  • Control equipment
  • Dimming or color zones
  • Service access

A production-ready drawing set should answer practical installation questions without relying on guesswork:

  • Which letter is installed first?
  • Where does each wire leave the letter?
  • Which cable enters which mullion?
  • Which supply serves each sign section?
  • Which cover must remain removable?
  • Who drills the frame?
  • Who provides the building circuit?
  • Which hardware is packed with the sign?
  • Which parts are installed by the glazier?
  • Which dimensions require site verification?

Approval should also follow version control. Each drawing should include:

  • Project name
  • Location
  • Drawing number
  • Revision number
  • Revision date
  • Prepared by
  • Approved by
  • Approval date
  • Production status

A useful status system is:

StatusMeaning
ConceptAppearance only; not for quotation or production
QuotationSufficient for pricing assumptions
Site reviewAwaiting local dimensions or engineering checks
ApprovalSent for review; not yet released
ApprovedVisual and technical details accepted
ProductionFrozen version released to manufacturing
As builtFinal installed arrangement recorded

When a revision changes size, letter depth, wiring, mounting, color, backer, or power supply, the old version should be withdrawn. Production should not rely on one approved elevation and a newer unapproved electrical sketch.

Iduoduo’s documented workflow transfers approved design and sample results into final shop drawings, sections, electrical drawings, mounting drawings, BOMs, finish schedules, QC checklists, packaging requirements, and a frozen production version.

How Is the Final Layout Verified?

Final verification should test the sign against the real site before materials are cut. The goal is to find conflicts while they are still inexpensive to correct.

Verification should happen at three levels:

  • Visual verification
  • Dimensional verification
  • Installation verification

Visual verification checks whether the sign looks correct on the glass. A scaled rendering can be placed over a straight site photograph. The overlay should show:

  • Actual glass boundaries
  • Mullion centerlines
  • Doors and handles
  • Ceiling lines
  • Nearby signs
  • Furniture or display fixtures
  • Proposed logo
  • Backer or raceway
  • Cable entry
  • Primary viewing position

The overlay should not stretch the logo or photograph to make the composition fit. Use known dimensions to maintain scale.

For important projects, produce a full-size paper template or plot. Position it on the glass at the intended height. A full-size check can reveal problems that remain unnoticed on a computer screen:

  • Letters appear too small from the entrance
  • A logo clashes with a mullion
  • The sign blocks a sightline
  • A wireway crosses a glass joint
  • A door handle overlaps the logo
  • The sign sits too close to a ceiling
  • Rear hardware falls directly at eye level
  • A power route is longer than expected

A practical template check should confirm:

CheckSuggested verification
Overall positionMeasure from floor and both glass edges
LevelUse a laser or spirit level
Character spacingCompare with approved artwork
Frame conflictMark all mullion centerlines
Door movementOpen doors through their full travel
Viewing heightCheck from standing and seated positions
Cable entryMark the exact frame or panel entry
Service accessOpen the intended ceiling or cabinet access
Rear viewInspect from the nearest occupied position

Dimensional verification should compare site measurements against the drawing. Record the measured value, drawing value, and allowable difference.

DimensionDrawingSite measurementDifferenceAction
Glass width3,000 mm2,994 mm−6 mmRecenter layout
Floor to sign center1,650 mm1,650 mm0 mmAccept
Right mullion width50 mm47 mm−3 mmRevise cable entry
Ceiling access opening600 × 600 mm580 × 580 mm−20 mmConfirm supply removal
Sign to mullion180 mm165 mm−15 mmShorten transition

The acceptable difference depends on the feature. A 5 mm difference in overall glass width may be manageable. A 5 mm difference in pre-drilled glass-hole position may not be.

Installation verification should trace the sign from letter to building circuit.

Follow every circuit physically on the drawing:

  1. The cable exits the letter.
  2. It enters the wireway, backer, or raceway.
  3. The grouped circuit reaches the mullion.
  4. It passes through the confirmed frame route.
  5. It enters the ceiling or cabinet.
  6. It reaches the correct power supply.
  7. The supply reaches the building circuit.
  8. The control system switches or dims the intended zone.
  9. Every serviceable part can still be accessed.

Any step described with words such as “somewhere,” “nearby,” “as required,” or “installer to decide” deserves another review. Some site decisions are unavoidable, but the production interface should be precise.

A final pre-production meeting is useful for glass-wall projects involving several parties. Participants may include:

  • Sign company
  • Brand or design representative
  • Local installer
  • Electrician
  • Glazier
  • Interior contractor
  • Factory engineer
  • Project manager

The meeting can be completed in 20–40 minutes when the drawings are ready. Review the following in order:

  • Final dimensions
  • Glass restrictions
  • Viewing directions
  • Mounting support
  • Wire exits
  • Cable route
  • Power supplies
  • Service access
  • Local responsibilities
  • Drawing revision
  • Production date
  • Installation date

The production release should record clear responsibilities:

ItemFactoryLocal team
Channel letter fabricationProduce to approved drawingsVerify delivery condition
LED and internal wiringInstall and testComplete site connections
Wire exitsPlace to drawingRoute into site enclosure
Power suppliesSupply as specifiedMount and connect where agreed
Installation templatePrepare and packPosition and use on site
Glass drillingProvide coordinated locationsGlazier approves and performs
Frame drillingShow intended pointsInstaller confirms and performs
Structural supportPrepare sign-side interfaceEngineer or contractor verifies building side
Building circuitProvide electrical requirementsElectrician supplies and connects
Permit and inspectionProvide available product informationLocal party obtains approvals

Before production begins, the approved package should include:

  • Final vector logo
  • Confirmed overall dimensions
  • Glass and frame information
  • Site photographs
  • Marked elevation
  • Front, rear, and side drawings
  • Mounting drawing
  • Electrical drawing
  • Power-supply schedule
  • Wire-exit schedule
  • Material and finish schedule
  • Approved color references
  • Backer, wireway, or raceway details
  • Installation template
  • Required certifications
  • Local responsibility list
  • Packaging and labeling instructions
  • Final revision number
  • Written production approval

For higher-risk projects, a sample or first article may be justified. Sample approval can confirm:

  • Metal finish
  • Acrylic color
  • Letter depth
  • LED color temperature
  • Brightness
  • Halo distance
  • Cable exit
  • Backer appearance
  • Rear finish
  • Mounting hardware
  • Packaging method

A sample should have a defined purpose. Approving only the face color does not automatically approve the wiring, brightness, rear finish, or installation method. The approval record should state exactly what the sample validates.

Iduoduo supports material samples, color samples, lighting samples, full-size sections, complete prototypes, pre-production samples, golden samples, first-article checks, first-store validation, and pilot production. Approved results are transferred into drawings, BOMs, process standards, mounting specifications, QC requirements, packaging instructions, and the final production version.

Production can begin when the site information and manufacturing documents tell the same story. The logo size should match the measured glass. The wire exits should match the confirmed frame route. The power supplies should fit through the service opening. The mounting parts should match the approved support. The drawing revision used by the factory should be the same revision held by the installer.

That alignment is what prevents a finished channel letter set from arriving at the site with nowhere to hide its wires.

What Should Be Confirmed Before Production?

Engineer reviewing channel letter drawings, wiring routes, mounting details, and glass wall measurements before production

Production should begin only after the visual design, glass conditions, mounting structure, electrical route, power-supply location, service access, and approved drawing version all match. A good rendering cannot replace measured site information. On glass, one incorrect assumption may leave a visible cable across the panel, place a power supply where no technician can reach it, or create mounting holes that do not match the finished glass.

For a conventional wall, installers can sometimes adjust a wire position behind the surface. Glass offers almost no room for correction. A cable exit moved by 50 mm may become visible. A raceway made 20 mm too deep may look heavy from inside the store. A power supply selected before the final cable length is known may produce voltage drop at the farthest letter.

Before releasing a glass-wall channel letter set, the production package should confirm six connected areas:

AreaInformation required before production
Sign appearanceFinal logo, dimensions, spacing, colors, finishes, lighting type and viewing directions
Glass constructionGlass type, thickness, panel size, coatings, frame system and drilling restrictions
MountingSupport method, fixing points, hardware, backer, raceway, wireway and installation template
ElectricalLED voltage, total load, circuit groups, wire exits, lead lengths, power supplies and controls
Site interfaceCable route, power location, service opening, ceiling access and local installation responsibilities
Production controlFinal drawings, BOM, finish schedule, sample standard, revision number and written approval

A production file should answer measurable questions. “Hide the wires near the frame” is not measurable. “All letter leads enter a 50 × 35 mm wireway and leave through the upper-right mullion, 2,250 mm above finished floor” gives the factory and installer the same instruction.

Which Site Photos Are Needed?

A complete site-photo package should show the sign area, the glass system, every important viewing direction, the proposed cable path, the power location, and all nearby obstructions. For a simple reception sign, 10–15 photographs may be enough. A storefront with several glass panels, doors, mullions, and ceiling conditions may require 20–30 photographs and a short walkthrough video.

One front photograph cannot answer the questions production needs. It may show the available width but hide the glass edge, rear view, ceiling access, frame depth, nearby door, or electrical cabinet.

The photo package should include the following views:

PhotoWhat must be visible
Full front elevationEntire glass panel, surrounding walls, frames, floor and ceiling
Marked sign areaProposed logo outline, centerline and mounting height
Rear elevationView from inside the room or store
Left-angle viewGlass depth, frame position and side visibility
Right-angle viewOpposite side, adjacent panels and cable-entry options
Upward viewHeader, ceiling grid, transom and possible service route
Downward viewBase channel, floor junctions and furniture conflicts
Mullion close-upsVisible width, joints, removable caps and sealant lines
Glass-edge close-upsPanel joints, exposed edges, clamps or fittings
Power locationOutlet, junction box, cabinet, ceiling access or electrical closet
Service accessOpening dimensions and available working space
Obstruction viewsDoors, handles, lights, sensors, sprinklers, cameras and air vents

Every important photo should include a known dimension. A tape measure placed across a mullion or beside the proposed logo area provides more value than a photograph with no scale.

Useful measurements include:

  • Glass panel width and height
  • Distance between mullion centerlines
  • Visible mullion face width
  • Frame depth
  • Distance from finished floor to sign centerline
  • Distance from sign edge to nearest frame
  • Ceiling height
  • Ceiling-access opening size
  • Distance from the sign to the proposed power supply
  • Available clearance behind a backer or cabinet
  • Door swing and handle projection
  • Distance from the nearest occupied viewing position

A straight photograph should be taken as square to the glass as possible. Strong perspective distortion makes a centered sign appear off-center and makes reliable overlay work difficult.

File names should identify the view. A useful naming system looks like:

  • 01-front-overall
  • 02-front-marked-position
  • 03-rear-overall
  • 04-left-mullion
  • 05-right-mullion
  • 06-top-header
  • 07-ceiling-access
  • 08-power-location
  • 09-glass-label
  • 10-door-clearance

Rear photographs are especially important. A logo may be approved from the street while exposed studs, cable loops, connector blocks, and an unfinished backer remain visible from inside. For a glass meeting room, the rear view may be seen from less than one metre away for several hours each day.

Viewing distance should be recorded with each important position:

Viewing distanceDetails likely to remain visible
Under 1 mCable printing, fasteners, adhesive edges, connector shapes and small gaps
1–3 mCable transitions, uneven wire routes, backer edges and mounting plates
3–5 mRaceway size, major hardware, cable loops and alignment errors
Over 5 mOverall sign position, backer proportions and large visible routes

A short site video should follow a fixed route:

  1. Begin 5–10 metres from the sign area.
  2. Walk toward the glass at normal eye level.
  3. Pass the sign from left to right.
  4. Show the rear side.
  5. Look upward toward the ceiling route.
  6. Open any cabinet, ceiling tile, or service panel.
  7. Show the proposed building power point.
  8. Return to the front and show nearby doors in motion.

A 45–90 second video often reveals conditions missed by still images. Common discoveries include a sliding door beside the logo, a ceiling bulkhead blocking cable access, furniture preventing maintenance, or a rear sightline that requires a double-finished backer.

At least one marked photograph should show:

  • Final proposed sign width
  • Final proposed sign height
  • Centerline
  • Distance from finished floor
  • Distance to left and right frames
  • Location of the wireway, raceway, or backer
  • Planned cable-entry point
  • Planned power-supply area
  • Primary front and rear viewing positions

The factory should never calculate sign size from a photograph alone. At least two verified site dimensions are required to scale an image reliably. Four dimensions are better: panel width, panel height, floor-to-centerline height, and distance to the nearest mullion.

When several identical locations are involved, each site still needs verification. A chain-store drawing may appear standardized, but local differences often include:

  • Different mullion spacing
  • Different ceiling height
  • Different glass films
  • Different power location
  • Different door position
  • Different landlord restrictions
  • Different rear visibility
  • Different installation access

A practical multi-site survey sheet can use one row per location:

StoreGlass widthSign widthNearest cable routePower locationRear visible?Site exception
Store 013,200 mm1,850 mmRight mullionCeilingYesDouble-finished backer
Store 022,950 mm1,700 mmLeft mullionSide cabinetNoShorter lead route
Store 033,450 mm1,850 mmNo usable mullionHeader racewayYesRaceway required

A five-minute survey check may prevent several hours of site rework. Missing photographs commonly lead to wrong wire exits, insufficient lead lengths, inaccessible power supplies, and mounting systems that conflict with the glass frame.

What Glass Details Matter?

The term “glass wall” does not define the mounting surface well enough for production. The project file should identify the glass type, thickness, panel construction, surface treatment, frame system, installation status, allowed penetrations, and approval authority.

The following glass details should be documented:

  • Tempered, laminated, insulated, annealed, curved, coated, or fire-rated
  • Single panel or multi-layer unit
  • Overall thickness
  • Individual layer thickness where laminated
  • Panel width and height
  • Clear, tinted, frosted, printed, or filmed surface
  • Existing factory-made holes
  • Distance from holes to panel edges
  • Exposed or framed glass edges
  • Manufacturer or fabricator
  • Already installed or still in fabrication
  • Warranty restrictions
  • Permitted adhesive, clamp, or fixing method
  • Maximum approved load where available

Glass thickness alone does not prove suitability. Two 12 mm panels can behave differently because one may be laminated, one tempered, one supported on four sides, and one held only at the top and bottom.

A glass-information table should be completed before mounting hardware is finalized:

ItemRequired entry
Glass systemTempered / laminated / insulated / other
Nominal thickness___ mm
Panel size___ × ___ mm
Surface finishClear / tinted / frosted / coated / film
Frame systemBrand or profile where available
Existing holesQuantity, diameter and coordinates
New holes allowedYes / no / pending approval
Adhesive allowedYes / no / test required
Clamp allowedYes / no / engineering required
Rear face visibleFully / partly / not visible
Approval sourceGlazier / architect / engineer / landlord

The production team should know whether the glass already exists.

When glass has not been fabricated, several features may still be coordinated:

  • Factory-made holes before tempering
  • Approved hole diameters
  • Hole centerlines
  • Edge distances
  • Printed opaque bands
  • Frosted areas
  • Concealed fixing plates
  • Wire-entry openings
  • Alignment with mullions
  • Structural backing around the sign area

When tempered glass is already installed, on-site drilling is generally not treated as a normal adjustment. Practical options may narrow to:

  • Existing holes
  • Frame-mounted raceways
  • Backer panels fixed to surrounding structure
  • Approved clamps
  • Approved adhesive systems
  • Ceiling-supported frames
  • Floor-supported frames
  • Independent structures beside the glass

Any proposed drilling should be confirmed by the glass fabricator, glazier, or qualified local professional before production.

For pre-planned through-glass holes, the drawing should show:

Hole informationWhy it is needed
DiameterMatches sleeve, bolt and protective bushing
X coordinateControls horizontal position
Y coordinateControls mounting height
Edge distanceHelps the glass specialist review the location
Hardware diameterPrevents an oversized metal part contacting glass
Gasket or sleeveSeparates metal from the glass surface
Installation toleranceAccounts for manufacturing and site variation
Tightening requirementReduces uncontrolled point pressure

Rigid stud patterns create little tolerance. A difference of 3–5 mm between the sign bracket and finished holes may stop installation. Adjustable mounting plates, slots, floating brackets, or oversized protective sleeves may be needed where the glass specialist approves them.

Surface films and coatings also affect the decision. A clear privacy film may look like bare glass in a photograph but can change adhesive performance. A bonding system attached to the film is only as strong as the film-to-glass bond.

The file should identify:

  • Film type
  • Film manufacturer
  • Installation date
  • Film position: front or rear face
  • Whether the sign bonds to glass or film
  • Whether a cut-out area is allowed
  • Whether removal will damage the film
  • Whether the adhesive creates a visible patch

Adhesive visibility is often underestimated. Through clear glass, even a transparent tape may reveal:

  • Air bubbles
  • Dust
  • Uneven pressure marks
  • Gloss differences
  • Yellowing over time
  • Darker patches behind metal plates
  • Irregular adhesive edges

For close-view installations, a full-size adhesive test panel is more reliable than a small sample. The test should use the actual glass finish, actual adhesive, actual metal or acrylic part, and expected curing time.

The frame system needs a separate record. A usable-looking mullion may contain internal parts that block wiring or prevent drilling.

Confirm the following frame information:

Frame conditionRequired check
Hollow cavityVerify by opening a cap or using a confirmed profile drawing
Continuous routeConfirm whether horizontal and vertical cavities connect
Drainage channelsKeep cable, foam and sealant clear
ReinforcementCheck for steel or internal fasteners
Thermal breakDetermine whether the cavity is divided
Removable coverConfirm removal direction and future access
Ceiling connectionCheck whether the route enters a usable void
Structural roleConfirm whether the frame may support the sign
Surface finishRecord color and sheen for matching
Drilling permissionObtain approval from the responsible trade

A cable route and a structural support are not the same thing. A mullion may accept a small low-voltage cable but may not be approved to carry the sign weight. Separate decisions are needed for electrical routing and load support.

Rear visibility should be classified early:

Rear-view conditionRecommended finish level
Completely hiddenFunctional rear wiring may remain inside an enclosure
Seen beyond 5 mMajor cable routes and raceways should be orderly
Seen from 2–5 mHardware, cables and covers should be color matched
Seen from 1–2 mUse enclosed connections and finished rear panels
Seen within 1 mConsider a double-skin backer or finished cabinet
Public-facing rear elevationTreat both sides as primary sign faces

A glass-partition sign visible from two offices often needs a boxed backer rather than a single flat panel. The front panel supports the letters and hides wiring; the rear panel conceals fasteners and provides removable access.

The Iduoduo engineering process converts storefront photographs, measurements, glass and wall information, installation requirements, shop drawings, sections, electrical plans, and mounting details into a controlled production version.

Where Is Power Available?

“Power is above the ceiling” is not enough. The file should identify the building supply point, selected power-supply location, low-voltage entry point, complete cable distance, switching method, service access, and local electrician’s responsibilities.

Three electrical points should be marked separately:

  1. Building mains supply
  2. LED power-supply location
  3. Low-voltage cable entry into the sign

Those points may be several metres apart.

For example:

Building junction box → 1.5 m mains cable → accessible cabinet → LED power supply → 6.8 m low-voltage cable → right mullion → 1.2 m wireway → channel letters

The project file should record:

  • Destination country and installation city
  • Building input voltage
  • Frequency
  • Dedicated or shared circuit
  • Plug-in or hardwired connection
  • Circuit breaker or protection arrangement
  • Switching method
  • Daily operating hours
  • Dimming requirement
  • RGB or RGBW control requirement
  • Indoor or outdoor location
  • Power-supply location
  • Distance from supply to letters
  • Cable route through frame, ceiling, cabinet, or raceway
  • Access-opening dimensions
  • Required certification or project documentation
  • Name of the local electrician or responsible contractor

Cable distance should be measured by route, not by a straight line across the drawing.

A practical route schedule may look like:

Route sectionLength
Supply to ceiling entry1.4 m
Ceiling route to right mullion3.2 m
Vertical route inside mullion1.8 m
Mullion to wireway0.2 m
Wireway to farthest group2.1 m
Service allowance0.3 m
Total one-way length9.0 m
Approximate two-conductor path18.0 m

An electrical calculation should use the complete outgoing and return conductor path. A one-way distance of 9 m does not mean only 9 m of conductor resistance.

Each power supply should receive an identification number and schedule:

IDSign sectionLED voltageCalculated loadSupply ratingLocationAccess
PS-01Left letters24 V68 W100 WCeiling bay ATile below
PS-02Right letters24 V73 W100 WCeiling bay ATile below
PS-03Halo circuit24 V46 W60 WSide cabinetFront door
CTRL-01Dimming control24 V compatibleSide cabinetFront door

The table should use actual approved LED loads before production. Letter width alone cannot predict power accurately. Stroke width, LED spacing, letter depth, lighting type, and internal geometry affect the module quantity.

When a planning limit of 80% load is used, the calculation should be shown:

Calculated load: 80 W
Maximum planned loading: 80%
Required rating: 80 W ÷ 0.80 = 100 W

The final loading limit must follow the selected power-supply instructions and project requirements.

The file should also state whether front and halo lighting operate together or separately.

Common control arrangements include:

  • One switch for all lighting
  • Separate front and halo switches
  • Fixed single-color lighting
  • Dimmable white lighting
  • Tunable white control
  • RGB controller
  • RGBW controller
  • Building-management-system control
  • Timer
  • Photocell
  • App or remote control

Separate zones require separate conductors, controls, labels, and commissioning checks. A front-and-halo-lit logo may need two output groups even when both use the same voltage.

Service access requires real dimensions. A small access symbol on a drawing does not prove a power supply can be removed.

Confirm:

  • Opening width and height
  • Power-supply dimensions
  • Connector clearance
  • Screwdriver clearance
  • Cover-removal direction
  • Ventilation space
  • Cable-bend space
  • Replacement path
  • Ladder or lift access
  • Furniture or ceiling obstructions
  • Ability to read the product label
  • Ability to measure voltage while energized

A useful clearance check compares part size with access size:

ItemSize
Power supply280 × 70 × 40 mm
Access opening300 × 100 mm
Connector projection25 mm
Required removal width305 mm
ResultOpening too small; revise before production

An enclosure may be technically removable while still being impractical. For example, a raceway cover facing the glass cannot open after the raceway is installed 10 mm from the panel.

Every circuit should be labeled at both ends:

  • PS-01 / CIR-A / LEFT
  • PS-01 / CIR-B / CENTER
  • PS-02 / CIR-C / RIGHT
  • PS-03 / HALO
  • CTRL-01 / DIMMER

For multi-store projects, add the store number:

  • ST012-PS01-CIR-A
  • ST012-PS02-HALO

The same code should appear on:

  • Electrical drawing
  • Cable label
  • Power-supply output
  • Installation guide
  • Packing list
  • Test record

Before production release, the local electrician should confirm:

Electrical itemConfirmation needed
Input voltage and frequencyMatches selected power supply
Hardwire or plug connectionAgreed before packing
Cable typeAccepted for the site and route
ConduitRequired or not required
Junction boxLocation and enclosure type
Grounding or bondingBuilding-side responsibility
DisconnectLocation and requirement
DimmingCompatible control and driver
CertificationRequired component or sign documentation
Final connectionLicensed local party identified

The factory may prepare the sign-side electrical system, but the building circuit, local hardwiring, permits, and final inspection belong to qualified local trades. Iduoduo’s documented engineering work includes LED and power matching, wiring, wire-exit planning, mounting preparation, electrical drawings, version control, and final production approval.

Which Drawings Need Approval?

A glass-wall channel letter project normally needs more than one artwork proof. The approved package should explain appearance, construction, mounting, wiring, service access, and the interface between factory-supplied parts and site work.

At minimum, approve:

  1. Front elevation
  2. Rear elevation
  3. Side section
  4. Mounting drawing
  5. Electrical drawing
  6. Raceway, wireway, or backer drawing where used
  7. Power-supply schedule
  8. Finish schedule
  9. Installation template
  10. Final production release

The front elevation should include:

  • Overall width and height
  • Individual letter heights
  • Logo proportions
  • Character spacing
  • Sign centerline
  • Position relative to mullions
  • Distance above finished floor
  • Face color
  • Return color
  • Trim color where applicable
  • Lighting method
  • Backer or raceway outline
  • Main dimensions in millimetres and inches where useful

“Centered on glass” should be replaced with dimensions. A glass panel, storefront opening, door group, and interior room may all have different visual centers.

The rear elevation should show:

  • Rear plates
  • Mounting studs
  • Nuts and washers
  • Backer edges
  • Raceway or wireway
  • Cable transitions
  • Frame entry
  • Connector positions
  • Service covers
  • Visible labels
  • Rear finish

Rear elevations expose unresolved details hidden by the front drawing. A project requiring a clean rear side should not proceed without one.

The side section should show:

Section itemRequired dimension
Glass thickness___ mm
Letter depth___ mm
Standoff from glass or backer___ mm
Backer thickness___ mm
Raceway depth___ mm
Wireway depth___ mm
Halo gap___ mm
Mounting hardware length___ mm
Access-cover clearance___ mm
Cable exit position___ mm

For halo-lit letters, the section should identify the surface receiving the halo. Clear space behind the letters does not create the same controlled glow as an opaque or frosted background.

The mounting drawing should define:

  • Number of fixing points
  • Hole coordinates
  • Fixing diameter
  • Bracket or rail position
  • Raceway attachment
  • Backer support
  • Approved load-bearing structure
  • Factory-supplied hardware
  • Site-supplied hardware
  • Template reference
  • Installation order
  • Required glazier or engineer approval
  • Adjustable tolerance where needed

A mounting drawing should answer, “What carries the weight?” A wireway may hide cables but may not carry the letters. A mullion may accept cables but may not be approved as a structural fixing.

The electrical drawing should show:

  • LED operating voltage
  • Total wattage
  • Power-supply IDs
  • Circuit groups
  • Letters assigned to each circuit
  • Polarity
  • Cable type
  • Lead lengths
  • Wire-exit positions
  • Connector positions
  • Frame-entry points
  • Controller or dimmer
  • Service access
  • Building connection boundary

A separate wire-exit schedule is useful for irregular logos:

PartExit positionLead lengthCircuitRoute
Letter AUpper right rear450 mmCIR-AInto wireway
Letter BCenter rear300 mmCIR-AInto wireway
Logo symbolLower left rear700 mmCIR-BTo left mullion
Halo backUpper center900 mmHALOTo header

A finish schedule should record measurable standards:

  • Face acrylic code
  • Return material
  • Metal grade
  • Paint reference
  • Pantone, RAL, CMYK, or approved sample
  • Gloss level
  • Brushed direction
  • Plating finish
  • LED color temperature
  • Backer color
  • Raceway color
  • Visible cable color

Color names such as “gold,” “warm white,” or “black” are too broad for repeatable production. Use a reference code or approved physical sample.

Drawing status should be controlled:

StatusMeaning
ConceptAppearance review only
QuotationPricing assumptions shown
Site verificationAwaiting measurements or local confirmation
For approvalTechnical package submitted
ApprovedAccepted but not yet frozen
Production releaseFinal version sent to manufacturing
As builtInstalled arrangement recorded

Every drawing should show:

  • Project name
  • Site location
  • Drawing number
  • Revision number
  • Revision date
  • Prepared by
  • Checked by
  • Approved by
  • Approval date
  • Production status

When a revision changes sign size, wiring, mounting, power supply, backer, raceway, or finish, the previous file should be removed from production use.

A revision log can prevent confusion:

RevisionDateChangeEffect
R0July 10Initial conceptNot for production
R1July 12Sign width reduced to 1,800 mmLetter scale changed
R2July 14Cable route moved to right mullionWire exits revised
R3July 16Added double-finished backerMounting and packing revised
R4July 18Final approvalProduction release

Approval should not be scattered between emails and chat messages. One final approval package should contain all active information.

The Iduoduo process transfers approved visual, structural, electrical, installation, material, and sample results into final drawings, BOMs, process standards, mounting specifications, QC checklists, packaging requirements, and a frozen production version.

How Is the Final Layout Verified?

Final verification should test the approved sign against actual site dimensions before metal, acrylic, or glass parts are cut. Verification should cover appearance, dimensions, mounting, wiring, access, installation sequence, and maintenance.

A reliable review uses four levels:

  1. Scaled site overlay
  2. Full-size template
  3. Route trace
  4. Responsibility check

A scaled overlay places the final logo drawing on a straight site photograph. The overlay should include:

  • Actual glass boundaries
  • Mullion centerlines
  • Doors and handles
  • Ceiling line
  • Floor line
  • Nearby lighting
  • Sign outline
  • Backer or raceway
  • Cable entry
  • Main viewing positions

The photograph should be scaled from verified dimensions. Stretching the image to make the logo fit can hide a site conflict.

A full-size paper template is valuable for high-visibility locations. Fix the template temporarily to the glass and verify:

  • Overall scale
  • Mounting height
  • Character spacing
  • Alignment with frames
  • Door clearance
  • Sightline from inside
  • Cable entry
  • Backer size
  • Raceway size
  • Rear visibility

A full-size template often reveals that a logo accepted on screen feels too small, too high, too close to a mullion, or too dominant on the glass.

Site and drawing dimensions should be compared in a verification table:

DimensionApproved drawingSite checkDifferenceDecision
Glass width3,000 mm2,994 mm−6 mmRecenter
Glass height2,600 mm2,600 mm0 mmAccept
Sign center height1,650 mm1,645 mm−5 mmAdjust template
Right mullion face50 mm47 mm−3 mmRevise cable cover
Ceiling opening600 mm540 mm−60 mmSelect smaller supply
Sign-to-mullion route180 mm230 mm+50 mmExtend controlled transition

Not every difference has equal importance. A 5 mm glass-width variation may be manageable. A 5 mm error in a pre-drilled hole pattern may prevent installation.

The complete cable route should be traced step by step:

  1. Lead exits each letter.
  2. Lead enters the wireway, backer, or raceway.
  3. Letter leads join the correct circuit group.
  4. Circuit reaches the approved mullion or frame entry.
  5. Cable passes through a confirmed cavity.
  6. Cable enters the ceiling or cabinet.
  7. Cable reaches the assigned power supply.
  8. Power supply connects to the correct control.
  9. Control connects to the building circuit.
  10. Every serviceable part remains accessible.

Every transition should have a dimension or clear location.

The same check should be completed for mounting:

  1. Letter or raceway attaches to the approved support.
  2. Support transfers load to a verified structure.
  3. Hardware does not place uncontrolled pressure on glass.
  4. Installation template matches the approved layout.
  5. Tools can reach every fixing.
  6. Rear hardware receives the required finish.
  7. One letter can be removed without dismantling the complete sign where planned.

A service simulation should also be performed on paper:

  • One power supply fails. Can it be removed?
  • One letter becomes dark. Can the circuit be tested separately?
  • A controller needs reset. Can the reset button be reached?
  • A wireway connector loosens. Can the cover open?
  • A letter face is damaged. Can the letter be removed without disturbing the glass?

A sign may be visually perfect but poorly serviceable. Maintenance access should be reviewed with the same care as appearance.

Before production, assign responsibility for every site interface:

Work itemFactoryLocal sign installerElectricianGlazier / contractor
Letter fabricationProduceInspect on delivery
Internal LEDs and wiringInstall and testVerify operation
Wire exitsProduce to drawingRoute on siteReview
Power suppliesSupply as specifiedPosition where agreedConnect
Building circuitProvide requirementsCoordinateSupply and connect
Glass holesProvide coordinatesCoordinateApprove and produce
Frame entryShow routeDrill where approvedConfirm protectionApprove
Mounting templateSupplyPosition and useReview interface
Structural supportPrepare sign-side partsInstallVerify building side
Final commissioningFactory test before shipmentInspect signElectrical testing

A pre-production review meeting can be completed in 30–45 minutes when documents are ready. Review the following order:

  • Final logo and dimensions
  • Glass and frame information
  • Primary and rear views
  • Mounting load path
  • Backer, wireway, or raceway
  • Wire exits
  • Cable route
  • Power-supply schedule
  • Service access
  • Local electrical connection
  • Installation responsibility
  • Packaging and labeling
  • Drawing revision
  • Production and installation dates

A production-release checklist should contain:

  • Final vector logo
  • Confirmed sign dimensions
  • Confirmed site dimensions
  • Glass specification
  • Frame information
  • Site photographs and video
  • Marked elevation
  • Front elevation
  • Rear elevation
  • Side section
  • Mounting drawing
  • Electrical drawing
  • Circuit schedule
  • Wire-exit schedule
  • Power-supply schedule
  • Material and finish schedule
  • Approved color references
  • Backer, raceway, or wireway drawing
  • Full-size template where needed
  • Local approval requirements
  • Responsibility list
  • Packing plan
  • Labeling plan
  • Revision number
  • Written production approval

For a high-value or multi-location program, a pre-production sample, full-size section, first article, first-store installation, or pilot batch may be justified. The sample should confirm named features rather than serve as a general visual check.

A sample-approval sheet may cover:

Sample itemApproved result
Letter faceMaterial, color and thickness
ReturnDepth, finish and seam quality
LightingBrightness, color temperature and uniformity
HaloGap, spread and receiving surface
Wire exitPosition and lead length
BackerColor, edge and rear finish
MountingHardware and template
ElectricalPower supply and circuit grouping
PackagingProtection and part labeling

Approved sample results should be transferred into final drawings, BOMs, production standards, QC checks, mounting instructions, and packaging requirements. Iduoduo’s documented process supports material samples, lighting samples, full-size sections, pre-production samples, golden samples, first-article approval, first-store validation, and pilot production for projects where visual or installation risk needs to be reduced before full production.

Production is ready only when the site information and factory documents give the same answer. The approved logo must fit the measured glass. Wire exits must point toward the confirmed cable route. Power supplies must fit through the service opening. Mounting hardware must match the approved support. The installer must hold the same revision used by the factory.

That final alignment is what prevents a finished channel letter set from arriving with nowhere to hide the wiring.

Plan Your Glass-Wall Channel Letters With Iduoduo

A clean glass-wall sign requires more than attractive letters. The wiring route, mounting structure, power-supply position, glass limitations, rear appearance, and maintenance access should be resolved before metal, acrylic, LEDs, and cables enter production.

Iduoduo can review a logo file, target dimensions, site photographs, glass and frame information, available power point, preferred lighting style, and required viewing directions. The design and engineering teams can then develop production-ready channel letters with planned wire exits, power matching, circuit grouping, raceway or backer options, installation templates, and coordinated accessories.

Founded in 2007, Iduoduo operates five production bases with 21,000 square metres of manufacturing space, more than 500 employees, 18 production lines, 10+ designers, 20+ engineers, and 30+ QC personnel. Illuminated products receive a 100% lighting check and 72-hour pre-shipment testing, supported by a three-year warranty under the confirmed project terms.

Send the logo, overall sign size, quantity, glass-wall photographs, destination country, input voltage, power-supply location, mounting restrictions, and required installation date when requesting a quotation. Those details allow the proposal to address the actual wall rather than provide a generic channel-letter price.

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