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.
63A 4 Pole 10kA MCB B Curve – WKC463B
£14.16
The WKC463B is a 63A 4 pole 10kA Miniature Circuit Breaker (MCB) designed for three-phase + neutral protection. With its B Curve trip characteristic, it is best suited to resistive load applications such as large socket outlet groups, small power distribution panels, and lighting circuits...
50A 4 Pole 10kA MCB B Curve – WKC450B
£14.16
The WKC450B is a 50A 4 pole 10kA Miniature Circuit Breaker (MCB) designed for three-phase + neutral systems. With a B Curve trip characteristic, it is intended for resistive load applications such as socket outlet groups, small power distribution boards, and general lighting circuits in...
40A 4 Pole 10kA MCB B Curve – WKC440B
£14.16
The WKC440B is a 40A 4 pole 10kA Miniature Circuit Breaker (MCB) for three-phase + neutral circuits. With its B Curve trip characteristic, this breaker is intended for resistive load circuits such as socket outlet banks, small distribution boards, and lighting groups in commercial three-phase...
32A 4 Pole 10kA MCB B Curve – WKC432B
£14.16
The WKC432B is a 32A 4 pole 10kA Miniature Circuit Breaker (MCB) for three-phase + neutral protection. With its B Curve trip profile, this breaker is suited for resistive load circuits such as general socket banks, lighting, and small sub-distribution panels across commercial three-phase boards,...
25A 4 Pole 10kA MCB B Curve – WKC425B
£14.16
The WKC425B is a 25A 4 pole 10kA Miniature Circuit Breaker (MCB) designed for three-phase + neutral circuits. With a B Curve trip profile, it is best used for resistive loads such as lighting banks, socket circuits, and small distribution panels in commercial three-phase boards,...
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.