What colour is a neutral conductor?

White where a neutral is required under CEC Rule 4-032; Rule 4-024 covers permitted white-with-coloured-stripe identification.

What colour is a bonding or grounding conductor?

Green or green with yellow stripes under CEC Rule 4-032. Those colours are reserved for grounding and bonding.

How does a circuit number map to a phase?

On a standard three-phase panelboard, circuits 1 and 2 are phase A, 3 and 4 are B, 5 and 6 are C, then the pattern repeats.

Which phase carries the high leg in a 4-wire delta system?

Canada puts the higher-voltage-to-ground conductor on phase A. The NEC puts the high leg on phase B.

Can colour identify an existing conductor?

No. Colour tells you what should be installed; it does not prove what an existing conductor is.

Wire Colour

Choose the system and conductor role, or enter a panel circuit number. The answer comes first; the rule behind it stays visible.

Electrical system

Where colour-coded circuits are required, CEC Rule 4-032 sets these colours.

Conductor role

Install this colour

This tells you what to install on new work. What is already in the wall is a meter question—verify with a meter before touching anything.

The Canadian colour sequence

CEC Rule 4-032 uses black and red for single-phase conductors, adds white where a neutral is required, and sets three-phase as A red, B black, C blue. Green and green/yellow are reserved for grounding and bonding.

What the circuit number tells you

Standard three-phase panel rows follow A, B, C in repeating pairs. For a 4-wire delta system, the Canadian rule makes phase A the higher-voltage-to-ground conductor; do not carry the U.S. phase-B position across the border.

Install by colour; identify by measurement

This tool answers what to install on new work. Legacy wiring, faded insulation and earlier mistakes make colour unreliable as an identification method.

Want to know why you should trust this result? Read how VoltDrop checks its numbers.

Frequently asked questions

What colour is a neutral conductor?: White where a neutral is required under CEC Rule 4-032; Rule 4-024 covers permitted white-with-coloured-stripe identification.
What colour is a bonding or grounding conductor?: Green or green with yellow stripes under CEC Rule 4-032. Those colours are reserved for grounding and bonding.
How does a circuit number map to a phase?: On a standard three-phase panelboard, circuits 1 and 2 are phase A, 3 and 4 are B, 5 and 6 are C, then the pattern repeats.
Which phase carries the high leg in a 4-wire delta system?: Canada puts the higher-voltage-to-ground conductor on phase A. The NEC puts the high leg on phase B.
Can colour identify an existing conductor?: No. Colour tells you what should be installed; it does not prove what an existing conductor is.