To test for a motor that is single-phasing, both ___ and ___ measurements must be taken, which are best performed while the motor is running.

To determine if a motor is single-phasing, measuring voltage and current is essential, especially while the motor is operating. Voltage measurements help identify if there is an imbalance in phase voltages, which can indicate the loss of one phase in a three-phase motor system. Current measurements reveal the distribution of load across the phases; in the case of single-phasing, one phase will show significantly lower or near-zero current, while the other phases may display normal operating currents.

Monitoring both voltage and current under running conditions provides critical real-time insights. Resistance or temperature measurements, while they can yield useful information about the motor's health, do not specifically indicate single-phasing issues. Resistance measurements are typically taken when the motor is off, and temperature measurements may not accurately reflect immediate electrical imbalances caused by phase loss. Therefore, focusing on voltage and current measurements while the motor is running is the most effective approach for diagnosing single-phasing.