Is a motor rated for 460V safe to use on a 480V circuit?

• A. No, it is not safe
• B. Yes
• C. Only if the voltage drop is within limits
• D. Only with a protection device

Answer: (B)

A motor’s nameplate voltage is a nominal target with allowable tolerance. A 460V motor is designed to tolerate voltages around that value, typically within about ±10%. A 480V supply is only about 4% higher than 460V, which falls well inside that common tolerance. That means the motor can operate safely without special adjustments, since the actual voltage at the motor terminals remains within what it was designed to handle.

Always confirm on the nameplate that 480V is within the acceptable range for that specific motor, as some motors may have tighter limits or be dual-rated (460/480V). The small voltage difference does not hinge on voltage drop along wiring, which is a separate consideration, nor does it require a special protection device beyond normal overcurrent protection.