In a 120/240-volt, 1Ø, 3-wire system, the circuit connected to the A-phase conductor is designated as AØ.

In a 120/240-volt, 1Ø, 3-wire system, the circuit connected to the A-phase conductor is designated as AØ.

• A. BØ
• B. NØ
• C. CØ
• D. AØ

Answer: (D)

In a 120/240 V single-phase, 3-wire system you have two hot conductors (the A and B phases) and a neutral. Branch circuits that use one hot leg and the neutral are labeled by the phase of the hot leg plus the neutral symbol. So a circuit fed from the A-phase is designated AØ, meaning “A to neutral.” The Ø indicates the neutral reference. BØ would be a circuit on the B-phase, which isn’t what’s described here, and CØ would only apply if there were a C-phase (three-phase system). NØ would refer to something tied to the neutral itself, not a branch circuit on a hot leg. Hence AØ is the correct designation.

In a 120/240 V single-phase, 3-wire system you have two hot conductors (the A and B phases) and a neutral. Branch circuits that use one hot leg and the neutral are labeled by the phase of the hot leg plus the neutral symbol. So a circuit fed from the A-phase is designated AØ, meaning “A to neutral.” The Ø indicates the neutral reference.

BØ would be a circuit on the B-phase, which isn’t what’s described here, and CØ would only apply if there were a C-phase (three-phase system). NØ would refer to something tied to the neutral itself, not a branch circuit on a hot leg. Hence AØ is the correct designation.