Pump motors shall be capable of operating the pump under full load with a voltage variation of what percentage from the nameplate reading?

The correct choice indicates that pump motors are required to operate efficiently and effectively under a voltage variation of 10% above or below the nameplate reading. This is important because electrical systems can experience fluctuations in voltage due to demand changes, system disturbances, or other factors.

Having a tolerance of 10% ensures that the pump motor can still function optimally without risking damage or reduced performance. If the voltage were to drop or spike significantly beyond this range, it could lead to insufficient power for the pump to operate correctly or cause overheating and damage to the motor. Hence, a standard of 10% effectively balances performance reliability with safety for both the motor and connected systems.

Ensuring compatibility with a standard voltage variation is critical for maintaining operational integrity in commercial pool facilities, where consistent water circulation and treatment are vital for health and safety standards.