Motor protection is divided into unfavorable operating conditions, faulty conditions, and system disturbances. Unfavorable operating conditions include mechanical overloads, under voltage, reverse rotation, harmonic effects, and voltage unbalance, which can lead to high temperatures. Faulty conditions involve short circuits between phases, earth faults, stalled rotors, prolonged starting times, and increased start/stop cycles. Small and medium low-tension motors are protected against overloads.

3.  Motor protection : divided into :
 " Unfavorable operating conditions “
 Faulty conditions
 System disturbances and switching surges (for HT
motors)

4. 1 - "Unfavorable operating conditions “
- Causes lead to high temperature:
1- mechanical over load
2-Under voltage
3- Reverse Rotation
4-Harmonic effects
5- Voltage unbalance

5. 2- Fault conditions:
-Sc between 2 phases
-fault Earth fault
-Stalling of Rotor
- Prolonged starting time
- Increase start & stop for motor times
- Single phasing condition

6.  Small and medium-sized LT motors:
1- Protection against Over Load :