Canadian Electrical Code wire colour standards?

The Canadian Electrical Code (CEC) establishes specific wire colour standards to ensure safety and consistency across all electrical installations in New Brunswick and throughout Canada.

Standard Wire Colours in the CEC

Hot (Line) Conductors:

• Black - Primary hot conductor for single-phase circuits


• Red - Second hot conductor in 240V circuits or multi-wire branch circuits


• Blue - Third hot conductor in three-phase systems


• Brown, orange, yellow - Additional hot conductors in complex multi-phase installations

• White or grey - Always used for grounded neutral conductors


• Must be clearly identified and never used for anything other than neutral

• Green - Equipment grounding conductor (bare copper is also acceptable)


• Green with yellow stripe - Also acceptable for grounding


• Bare copper - Most common for equipment grounding in residential applications

Three-Phase Colour Standards

For three-phase systems common in commercial and industrial applications in New Brunswick:

• Phase A: Black


• Phase B: Red


• Phase C: Blue


• Neutral: White or grey


• Ground: Green or bare

Important New Brunswick Considerations

TSANB Compliance: All wire colour coding must follow CEC standards as adopted by the Technical Safety Authority of New Brunswick. Inspectors will verify proper colour coding during electrical inspections, and non-compliance can result in failed inspections.

Older Installations: Many older homes in New Brunswick may have non-standard wire colours, particularly in knob and tube or early Romex installations. When upgrading these systems, electricians must bring colour coding up to current CEC standards.

Maritime Environment: In coastal areas of New Brunswick like Saint John or Shediac, the salt air doesn't affect wire colour requirements, but it's crucial that all connections are properly made according to colour standards to prevent corrosion-related failures.

Safety Critical Points

Never assume wire function by colour alone - always test with a multimeter before working on any circuit. Old installations may have incorrect or faded wire colours, and some DIY work may not follow proper standards.

White wires can be hot in switch loops and certain configurations, but they must be properly marked with black tape or other identification when used as hot conductors. This is a common source of confusion and potential safety hazards.

Most electrical work involving new circuits or modifications requires TSANB permits and must be performed by licensed electricians who understand proper wire colour applications and CEC requirements.

Need help finding a licensed electrician who follows proper CEC wire colour standards? New Brunswick Electrical can match you with qualified professionals in your area who ensure all work meets TSANB requirements and current code standards.