Starting problems usually come not from the motor itself but from the supply and starting arrangement. Working in this order saves time:

  1. Are all three phases present? If the motor hums but does not turn, the first suspect is phase loss; check fuses, contactor contacts and terminal leads.
  2. How far does voltage drop at starting? Measure at the motor terminals during the start. A severe drop points to cable size or transformer capacity.
  3. Do the links match the nameplate? Leaving a 400/690 V motor in star cuts torque to one third.
  4. Does the starting method suit the load? Star-delta, or a soft starter set with too low an initial voltage, may not accelerate a heavy load.
  5. Is the load free? Jammed material, a mechanism left braked, an over-tensioned belt or a binding gearbox can lock the motor; uncouple the load and try at no load.
  6. Is the protection set correctly? If the thermal relay is set too low or its trip class does not suit the starting time, the circuit opens before the motor accelerates.

If the motor starts easily at no load but not under load, the power rating or starting method must be reconsidered; message us on WhatsApp with a nameplate photo and machine details.