Introduction
An MCB (Miniature Circuit Breaker) is an electrical safety device used to protect electrical circuits from overload and short circuits. It automatically switches off the power supply when excess current flows through the circuit.
Why is an MCB Important?
When the current exceeds the safe limit:
- The MCB detects the fault.
- It automatically trips (switches OFF).
- The power supply is disconnected.
- After fixing the problem, the MCB can be switched ON again.
Types of MCB
1. Type B MCB
- Used in homes
- Trips at 3–5 times the rated current
2. Type C MCB
- Used in commercial buildings
- Suitable for motors and air conditioners
3. Type D MCB
- Used in industries
- Handles high starting currents
Advantages of MCB
- Fast operation
- Easy to reset
- Reliable protection
- Long service life
- Low maintenance