During a stall test, which finding could indicate a stuck or seized stator?

During a stall test, which finding could indicate a stuck or seized stator?

• A. Higher than normal stall speed
• B. Extremely low stall speed
• C. No temperature decrease during the cool down phase
• D. Low torque during the stall test

Answer: (C)

During a stall test you’re watching how the motor behaves when it’s not able to turn freely and how heat builds up and then dissipates. If the stator is stuck, the rotor can’t rotate and the windings stay under load, continuing to generate heat. At the same time, lack of rotor movement reduces cooling effectiveness inside the motor, so when you move to the cool-down phase you don’t see the expected drop in temperature. That persistent heat, with no cooling, is a telltale sign that the stator may be seized. Other observations, like a higher or lower stall speed or reduced torque during the stall, point to different electrical or mechanical issues, but they don’t specifically indicate a stuck stator the way the absence of a temperature drop during cooldown does.

During a stall test you’re watching how the motor behaves when it’s not able to turn freely and how heat builds up and then dissipates. If the stator is stuck, the rotor can’t rotate and the windings stay under load, continuing to generate heat. At the same time, lack of rotor movement reduces cooling effectiveness inside the motor, so when you move to the cool-down phase you don’t see the expected drop in temperature. That persistent heat, with no cooling, is a telltale sign that the stator may be seized.

Other observations, like a higher or lower stall speed or reduced torque during the stall, point to different electrical or mechanical issues, but they don’t specifically indicate a stuck stator the way the absence of a temperature drop during cooldown does.