What voltage rating is used in the 0.5-hp, three-phase example?

What voltage rating is used in the 0.5-hp, three-phase example?

• A. 120 V
• B. 230 V
• C. 460 V
• D. 575 V

Answer: (B)

Small three-phase motors are commonly rated for 230/460 V in the US. In the 0.5-hp example, the problem uses a 230 V three-phase supply, which is typical for compact motors. When wired for 230 V service (delta connection), each winding sees 230 V, matching the low-voltage rating. Higher voltages like 460 V or 575 V are used for larger motors or different equipment, and 120 V is a single-phase supply, not a three-phase motor scenario. So the voltage rating used in the example is 230 V.

Small three-phase motors are commonly rated for 230/460 V in the US. In the 0.5-hp example, the problem uses a 230 V three-phase supply, which is typical for compact motors. When wired for 230 V service (delta connection), each winding sees 230 V, matching the low-voltage rating. Higher voltages like 460 V or 575 V are used for larger motors or different equipment, and 120 V is a single-phase supply, not a three-phase motor scenario. So the voltage rating used in the example is 230 V.