MCB, MCCB, ACB, and VCB are most common types of Circuit breakers. Circuit breakers are essential devices that we use to protect electrical systems from faults and overloads. They come in different types depending on the application, voltage level, and breaking capacity.
MCB (Miniature Circuit Breaker)
- Range: Up to ~100 A, <1 kV.
- Use: Homes, offices, small commercial loads.
- Function: Trips during overload or short-circuit.
- Advantage: Compact, quick response, maintenance-free.
MCCB (Moulded Case Circuit Breaker):
- Range: Up to ~2500 A, <1 kV.
- Use: Industries, LV distribution, large motors.
- Feature: Adjustable trip settings, higher breaking capacity.
- Advantage: Can handle large currents and fault levels.
ACB (Air Circuit Breaker):
- Range: Up to 690 V, thousands of Amps.
- Use: Substations, switchgear, busbar protection.
- Feature: Air is used as arc extinguishing medium.
- Advantage: High breaking capacity, can be used for main incomers.
VCB (Vacuum Circuit Breaker):
- Range: 3.3 kV – 33 kV.
- Use: Medium voltage distribution & substations.
- Feature: Arc is extinguished inside a vacuum chamber.
- Advantage: High reliability, minimal maintenance, long life.
Comparison Table:
| Device | Voltage Range | Current Range | Arc Medium | Typical Use |
|---|---|---|---|---|
| MCB | <1 kV | Up to 100 A | Air | Homes, small loads |
| MCCB | <1 kV | Up to 2500 A | Air | Industrial LV systems |
| ACB | <1 kV | Thousands of A | Air | Substations, busbars |
| VCB | 3.3 – 33 kV | High | Vacuum | MV distribution |