What could be the reason for constant tripping of a three phase induction motor

Explain why constant tripping happens in a three phase induction motor

IT could be due to many reasons

Voltage drop issue’s

unbalancing current

Need to check mA of breaker

Phase Imbalance, The problem might also be due to the coils so check your coils

Check loaded condition

Check phase balance condition

Check overload relay setting

Check MCB amp rating

Check mechanical side such as bearings and load side rotation bearings, gearbox etc

Check if the current reading of all 3 phases are approximately equal

Check the supply voltage, check contactor contacts

When troubleshooting induction motor fault, start from the simplest to the hardest.MCB tripping occurs mostly due to short circuits, make sure you check the motor terminal box sometimes you will find that cables got loose due to motor vibration and get contact hence creating a short circuit. if no fault in the terminal box move to the motor starter panel and check if the cables and contactors are in good condition, if no fault is found continue to the next level, ensure the power supply cable also has no short circuit. if no fault is detected now is high time to reason like a grown-up and to test the motor, remember sometimes a fault may not be detected by multimeter if motor stator winding insulation gets weaken. if you have a power analyzer this will help you to detect the fault. Point to remember, if it is over temperature, that the work of OL to trip if is phase imbalance and voltage asymmetrical that the work of phase failure. In conclusion, MCB constant tripping and is sure bet Short circuit.