If a furnace blower motor is rated at 230V, what is the allowable voltage variance?

The allowable voltage variance for a furnace blower motor rated at 230V is typically ±10%. This range is established to ensure that the motor can operate effectively without risking damage due to fluctuations in the electrical supply.

A voltage supply that deviates beyond this variance can lead to inefficient operation or potential failure of the motor. If the voltage were to drop too low, the motor may not start or run at the desired speed, while too high of a voltage could cause overheating or shorten the motor's lifespan.

The ±10% variance means that the motor can effectively operate within a voltage range of 207V to 253V without adverse effects. This standard helps maintain optimal performance and reliability for the motor while providing a buffer against typical variations in electrical supply.