SERVICE
After starting the motor, it was observed that the no-load currents of all three phases are balanced, but the current values are relatively high, and the motor heats up rapidly.
This may be due to an excessively high supply voltage, or because a Y‑connected motor has been mistakenly wired in a Δ configuration. Check the power supply and restore the rated voltage, or, following the correct wiring method, rewire the Δ connection as a Y connection.
It could also be due to an excessively low supply voltage, combined with the motor operating under its rated load, causing excessive current and resulting in overheating of the windings.
If abnormal noises can be heard, they can be used to diagnose the issue, or the motor can be disassembled to check for any rubbing between the stator and rotor laminations.
Alternatively, check the motor’s nameplate rating to determine whether the motor is overloaded (i.e., a small motor driving a heavy load) or experiencing overheating due to frequent starting.
