Which colors are commonly used for hot conductors in a standard US residential circuit?

Which colors are commonly used for hot conductors in a standard US residential circuit?

• A. Blue and green may be used for hot conductors in some specialized systems.
• B. Black and red (on multi-wire branch circuits; blue may be used in some systems).
• C. White.
• D. Green or bare.

Answer: (B)

Hot conductors are color-coded to show live power. In a standard US residential circuit, black is the typical hot wire. When a second hot is needed in the same cable (a multi-wire branch circuit sharing a neutral), the second hot is red. This helps identify the two hot legs and supports using a two-pole breaker to shut off both simultaneously for safety. Blue can appear as a hot in some systems or special installations, but it isn’t the usual color for standard circuits. White is neutral, and green or bare wires are grounding conductors.

Hot conductors are color-coded to show live power. In a standard US residential circuit, black is the typical hot wire. When a second hot is needed in the same cable (a multi-wire branch circuit sharing a neutral), the second hot is red. This helps identify the two hot legs and supports using a two-pole breaker to shut off both simultaneously for safety. Blue can appear as a hot in some systems or special installations, but it isn’t the usual color for standard circuits. White is neutral, and green or bare wires are grounding conductors.