L – Long Time Protection (Overload) :
- Protects against sustained overload currents
- Based on thermal characteristics of conductors and equipment
- Adjustable current setting (Ir) and time delay (tr)
- Ensures cables and loads are not overheated
S – Short Time Protection :
- Protects against short-circuit currents with a time delay
- Allows coordination with downstream breakers (e.g., MCCB)
- Prevents unnecessary tripping of upstream breakers
I – Instantaneous Protection :
- Trips the breaker instantly during severe fault conditions
- No intentional delay is applied
- Protects against very high fault currents
G – Ground Fault Protection :
- Detects leakage or fault current flowing to ground
- Helps prevent:
- Equipment damage
- Fire hazards
- Adjustable sensitivity for different applications.