MCBs
MCBs (miniature circuit breakers) protect electrical circuits against overload and short circuit faults . They are used in consumer units, distribution boards, and three-phase installations to disconnect power automatically when current rises beyond a safe level. This collection...
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MCBs – Miniature Circuit Breakers for Domestic & Commercial Circuits
MCBs (miniature circuit breakers) protect electrical circuits against overload and short circuit faults. They are used in consumer units, distribution boards, and three-phase installations to disconnect power automatically when current rises beyond a safe level.
This collection includes Type B MCBs for standard circuits, Type C MCBs for circuits with higher inrush current, and selected specialist options for more demanding applications. Whether you’re replacing a single breaker or specifying a full board, this is the main hub for our MCB range.
Quick answer: An MCB is a resettable circuit breaker that protects wiring and connected equipment from overload and short circuit faults. The right MCB depends on the circuit rating, fault level, and whether you need a B curve, C curve, or more specialist trip characteristic.
MCBs are one of the most common circuit protection devices used in UK electrical installations. They are fitted across consumer units, three-phase boards, and enclosure-based builds to provide fast disconnection under fault conditions while remaining easy to reset once the issue is resolved.
- Type B MCBs – commonly used on standard domestic circuits such as lighting and sockets
- Type C MCBs – suited to circuits with higher start-up or inrush current
- Selected D curve options – for more specialist high-inrush applications
- Multiple ratings and pole formats – for domestic, commercial, and three-phase use
- 6kA and 10kA options – depending on installation requirements
Need earth leakage protection as well? Browse our RCBO range. For delivery and returns, see our delivery information and returns policy.
Forward orders accepted
10 Way Heat Pump Consumer Unit with Type B HP RCD + RCBOs
£265.95 ex. VAT
£319.14 inc. VAT
Choosing the Right MCB
Select an MCB from the circuit design—not by amp rating alone. The device must coordinate with the conductor, connected load, prospective fault current and upstream protection. Confirm the required trip curve, pole format and breaking capacity before ordering.
B Curve MCBs
Commonly used where normal inrush current is relatively low, including many lighting, socket and general-purpose circuits. Suitability still depends on the design calculations.
C Curve MCBs
Allow a higher instantaneous trip threshold than B curve devices and are often considered for loads with greater starting current, subject to the required disconnection times.
Pole & Breaking Capacity
Choose single-, two-, three- or four-pole formats for the supply and isolation requirement, then verify whether a 6kA, 10kA or other rated breaking capacity is needed.
Specification Checklist
- Current rating: coordinate with design current and conductor capacity
- Trip curve: match the load’s normal operating and inrush characteristics
- Breaking capacity: verify against the prospective fault current at the installation point
- Pole configuration: confirm the supply arrangement and required conductor isolation
- Board compatibility: check manufacturer range, module width and terminal arrangement
Selection Guides
Related Categories
Circuit Protection6kA MCBs10kA MCBsRCBOsThree Phase
Trade support: UK-stocked products, manufacturer-backed specifications and fast dispatch. Check each product page for ratings, standards, stock status and delivery details before ordering.