A 3 phase motor shows 15 FLA. You have readings of 15.6, 16.1 and 15.9, what is the condition of the motor?

A 3 phase motor shows 15 FLA. You have readings of 15.6, 16.1 and 15.9, what is the condition of the motor?

• A. Normal
• B. Underloaded
• C. Overloaded
• D. Stalled

Answer: (C)

Interpreting motor condition hinges on how the current compares to the motor’s full-load current (FLA). If the three-phase currents stay near or below the rated FLA, the motor is running normally or underloaded. If the currents exceed the FLA, the motor is working harder than intended and is considered overloaded. A stalled motor would draw a current far above the normal range, typically much higher than the FLA, and not just modestly above it. In this case, the rated FLA is 15 A, while the measured currents are 15.6, 16.1, and 15.9 A. All three are above the rated 15 A, though only modestly. They’re fairly balanced, which means the issue isn’t a phase being out of phase or a stall, but that the motor is drawing more current than its rated-load value. That indicates an overloaded condition.

Interpreting motor condition hinges on how the current compares to the motor’s full-load current (FLA). If the three-phase currents stay near or below the rated FLA, the motor is running normally or underloaded. If the currents exceed the FLA, the motor is working harder than intended and is considered overloaded. A stalled motor would draw a current far above the normal range, typically much higher than the FLA, and not just modestly above it.

In this case, the rated FLA is 15 A, while the measured currents are 15.6, 16.1, and 15.9 A. All three are above the rated 15 A, though only modestly. They’re fairly balanced, which means the issue isn’t a phase being out of phase or a stall, but that the motor is drawing more current than its rated-load value. That indicates an overloaded condition.