⚡ 1. Overload protection Protects motor from running at high currents for too long (due to mechanical overload, jam, etc.).
Example: Thermal overload relay.
⚡ 2. Short-circuit protection Protects motor winding from very high fault currents.
Example: Circuit breakers (MCB, MCCB, fuse).
⚡ 3. Ground fault (earth fault) protection Protects against leakage currents to earth, preventing electric shock and fire.
Example: Earth fault relay.
⚡ 4. Phase failure (single phasing) protection Protects against loss of one phase in 3-phase motors.
Example: Phase failure relay.
⚡ 5. Phase sequence protection Ensures correct rotation direction and protects against wrong phase sequence.
Example: Phase sequence relay.
⚡ 6. Under-voltage protection Trips the motor if voltage drops below safe limits, preventing overheating or stalling.
Example: Under-voltage relay.
⚡ 7. Over-voltage protection Protects against high voltage which can damage insulation.
Example: Over-voltage relay.
⚡ 8. Locked rotor protection Protects when the rotor cannot turn while current is high (e.g., mechanical blockage)