Introduction
Signal wiring arrangements and colour conventions vary by model, controller interface and project. Use the approved connection diagram and conductor schedule to identify each function, including any permitted common connection. Confirm the destination project’s labelling and colour requirements before installation. Do not infer a universal switched-conductor and common-return arrangement for all traffic signals. This guide discusses how to document those connections.
Conductor schedule
Select the cable’s conductor count, cross-sections and identification scheme from the approved wiring design and applicable electrical requirements. A regional label alone does not define a safe signal-to-colour mapping.
| Circuit function | Required verification |
|---|---|
| Red, yellow and green signal outputs | Identify each output conductor by its terminal assignment and the approved wiring drawing; do not assume a regional insulation-colour convention. |
| Common or return conductor | Confirm the circuit topology, supply type and designated common terminal before connecting. A common conductor is not automatically a protective-earth conductor. |
| Protective earthing | Identify and connect protective earthing according to the applicable electrical rules and approved equipment drawings. Do not substitute it for a signal output. |
| Verification before energising | A qualified person should verify terminal labels, continuity and protective measures with the circuit safely isolated, using the approved test procedure. |
US NEC (United States)
Confirm conductor identification under the electrical code adopted for the project, the road authority’s requirements and the equipment diagrams. Do not assume that a generic colour table establishes compliance for every US traffic-signal installation.
IEC Europe and Export
For a European project, confirm conductor identification from the applicable electrical requirements and approved wiring diagrams. EN12368 must not be used as a substitute for the installation’s wiring rules, and green/yellow protective-conductor identification must not be assigned to a signal phase.
China GB
China project check: confirm the applicable electrical rules and approved conductor schedule.
Australia / New Zealand AS/NZS
Australia/New Zealand project check: confirm the applicable electrical rules and approved conductor schedule.
Project-Specific Conventions
Confirm the project cable-identification scheme and applicable electrical rules before installing wiring. Project conventions must not be assumed to override mandatory conductor-identification requirements. Identify functions from approved diagrams rather than colour alone, and confirm available cable options with GAOQIAO for the selected specification.
Frequently Asked Questions
The connection scheme must satisfy applicable mandatory requirements and the approved project design. If the project specification conflicts with regional rules or the equipment documentation, stop and obtain clarification from the responsible designer before wiring. Use the confirmed terminal and conductor identification; do not resolve a conflict by choosing a wire colour on assumption.
Confirm whether the proposed conductor identification is permitted by the applicable electrical requirements and approved project design, including any special or short-run installation. The identification must remain clear for inspection and maintenance. Do not assume that a short cable run removes the need for the specified colour coding or terminal labels.
Conclusion
Wire-colour conventions vary by region and project. Confirm the approved specification and connection diagram before selecting or installing cable. Ask GAOQIAO to confirm the available conductor identification, cable type and supply scope for the destination project. Do not assume every requested cable specification is available without review.
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Relevant GAOQIAO products
These public GAOQIAO catalogue pages are related to the guide. Open them for the representative description, then confirm the latest drawing and configuration before ordering.
- Traffic signal controllersWired and solar controllers with 6, 22, 44 and 56 output options.
- LED traffic signal heads200mm, 300mm and 400mm signal heads; confirm the selected model and applicable project requirements.
- Signal polesVertical, signal arm and double-arm poles; confirm suitability for the approved site design.
- Spare parts and accessoriesSpare LED modules, lenses, visors, surge arrestors and anchor bolts.