MCBs – Miniature Circuit Breakers
Miniature Circuit Breakers (MCBs) protect against overloads and short circuits, ensuring circuits disconnect safely under fault conditions. We stock Type B MCBs for domestic circuits and Type C MCBs for commercial/industrial loads, plus selected Type D options for specialist use. All are BS EN 60898 compliant and shipped with next-day UK delivery.
Read more
All our MCBs are clearly labelled, long-life tested, and essential in consumer units and three-phase boards to protect wiring and appliances. They disconnect circuits rapidly in the event of overload or fault, preventing damage and ensuring compliance with 18th Edition Wiring Regulations.
- Type B MCBs – trip at 3–5x rated current; ideal for sockets and lighting
- Type C MCBs – trip at 5–10x rated current; suited to motors, pumps, fluorescent lighting
- Type D MCBs – trip at 10–20x rated current; specialist option for high inrush equipment
Looking for combined overload + earth leakage protection? See our RCBO range. For returns support, check our returns policy.
6kA MCB – 50A 1 Pole B Curve (WMC150B)
£1.84
£2.99
The WMC150B is a 50 A single-pole 6 kA Miniature Circuit Breaker (MCB) providing dependable overcurrent and short-circuit protection for heavy-duty feed circuits and fixed equipment. Its B-curve tripping characteristic (3–5 × In) ensures rapid disconnection on faults while maintaining stable operation on steady loads....
6kA MCB – 40A 1 Pole B Curve (WMC140B)
£1.84
£2.99
The WMC140B is a 40 A single-pole 6 kA Miniature Circuit Breaker (MCB) built for high-load domestic and light-commercial circuits such as sub-mains, electric heaters and distribution feeds. Its B-curve tripping profile (3–5 × In) delivers fast, reliable protection against overcurrent and short-circuit faults while...
6kA MCB – 20A 1 Pole B Curve (WMC120B)
£1.84
£2.99
The WMC120B is a robust 20 A single-pole 6 kA Miniature Circuit Breaker (MCB) providing accurate overcurrent and short-circuit protection for socket and radial circuits in homes, garages and light-commercial buildings. It features a B-curve tripping profile that operates at 3–5 × rated current to...
6kA MCB – 16A 1 Pole B Curve (WMC116B)
£1.84
£2.99
The WMC116B is a 16 A single-pole 6 kA Miniature Circuit Breaker (MCB) designed for socket and small-power radial circuits. It combines dependable overcurrent and short-circuit protection with a B-curve tripping characteristic that responds at 3–5 × rated current — ideal for domestic and light-commercial...
50A 2 Pole 10kA MCB – C Curve (WKC250C)
£7.49
The WKC250C is a 50 A 2 Pole 10 kA Miniature Circuit Breaker (MCB) designed for high-demand single-phase or split-load circuits with moderate inrush current. With a C-curve tripping profile, it provides reliable protection for plant equipment, heating systems, and heavy lighting circuits where initial...
What Is an MCB?
An MCB (Miniature Circuit Breaker) is an automatically operated switch that trips to protect circuits from overload (too much current) or short circuit faults. They replace traditional fuses, offering quicker reset, safer operation, and compliance with BS EN 60898.
Types of MCBs
- Type B – trips at 3–5x rated current; standard for domestic circuits such as sockets and lighting. Popular choice:10kA MCBs (Type B).
- Type C – trips at 5–10x rated current; used for inductive/motor loads in workshops and commercial sites. Example: 1-Pole 10kA Type C MCB.
- Type D – trips at 10–20x rated current; for industrial kit with high inrush current (specialist use).
MCB Ratings & Sizes
MCBs come in a range of current ratings, typically from 6A to 100A. Choose the correct pole configuration and breaking capacity for your install:
- Single pole – most domestic circuits
- Double pole – where both live and neutral must be isolated
- Three/four pole – used in three-phase distribution boards
Compliance
All our MCBs meet BS EN 60898 standards, making them fully compliant with the 18th Edition Wiring Regulations. This ensures safe disconnection times and compatibility with modern UK boards.
FAQs on MCBs
What’s the difference between an MCB and an RCBO?
An MCB protects against overloads and short circuits. An RCBO combines this with RCD protection for earth leakage faults.
How do I choose between Type B and Type C?
Use Type B for domestic circuits with low inrush currents (sockets, lighting). Use Type C for circuits with motors, pumps, or fluorescent lighting.
Do MCBs need replacing after they trip?
No – unlike fuses, MCBs can be reset once the fault is cleared, making them reusable and safer.
Why Buy From Power & Data UK?
All MCBs are UK stocked, BS EN compliant, and supplied with a 2-year warranty. Orders placed before 2pm ship same-day with next-day delivery on purchases over £30. If you need to return an item, see our returns policy.