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.
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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.
50A 2 Pole 10kA MCB – B Curve (WKC250B)
£7.49
The WKC250B is a 50A 2 Pole 10kA Miniature Circuit Breaker (MCB) engineered for heavy-duty protection of fixed power and distribution circuits. With a fast-acting B-curve tripping profile, it provides reliable disconnection under overload or short-circuit conditions in heating systems, small machinery, and industrial plant...
40A 2 Pole 10kA MCB – B Curve (WKC240B)
£7.49
The WKC240B is a 40A 2 Pole 10kA Miniature Circuit Breaker (MCB) designed to protect higher-load radial and feeder circuits against short-circuit and overload faults. The B-curve tripping profile ensures rapid disconnection for resistive and low-inrush circuits such as outbuilding sub-mains, immersion heaters, and EV...
32A 2 Pole 10kA MCB – B Curve (WKC232B)
£7.49
The WKC232B is a 32A 2 Pole 10kA Miniature Circuit Breaker (MCB) providing fast and reliable protection against short-circuit and overload faults. Designed for ring mains, small distribution boards, and fixed-appliance feeds, this B-curve breaker offers quick disconnection for resistive and low-inrush circuits. Its dual-pole...
25A 2 Pole 10kA MCB – B Curve (WKC225B)
£7.49
The WKC225B is a 25A 2 Pole 10kA Miniature Circuit Breaker (MCB) designed for dependable protection of small-power and distribution circuits. With a B-curve tripping profile, it delivers rapid response to short-circuit and overload faults in garage supplies, air-conditioning units, and lighting control panels. Its...
20A 2 Pole 10kA MCB – B Curve (WKC220B)
£7.49
The WKC220B is a 20A 2 Pole 10kA Miniature Circuit Breaker (MCB) built for reliable short-circuit and overload protection on small power, lighting, and radial circuits. With a B-curve tripping profile, it reacts quickly to overcurrents in resistive or lightly inductive loads such as air...
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: WKB 10kA MCBs.
- 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.