Circuit Protection Devices – RCBOs, RCDs & MCBs
Explore our full range of circuit protection devices – from MCBs and RCDs to advanced RCBOs. Whether you're upgrading a board, replacing a tripped unit, or speccing out a new install, we’ve got you covered. All products are 18th Edition compliant, BS EN certified, and UK-stocked for next-day delivery.
Read more about circuit protection
Circuit protection is the foundation of every safe electrical installation. Under BS 7671 (18th Edition), all circuits must be protected against overload, short circuit, and earth leakage faults. The right device not only keeps people safe but also ensures installations pass inspection and remain insurable.
- MCBs – trip automatically when circuits are overloaded or short-circuited, replacing old-style fuses with faster, safer operation.
- RCDs – protect against earth leakage and electric shock, mandatory on most final circuits in the UK.
- RCBOs – combine the functions of MCBs and RCDs in one device, reducing nuisance trips and offering per-circuit protection.
- Type B RCDs – essential for EV, solar, and inverter-driven equipment where DC fault protection is required.
- High Immunity RCBOs – prevent false tripping in circuits with harmonics or inverter noise.
- AFDD RCBOs – detect dangerous arc faults that standard breakers miss, reducing fire risks in HMOs and rentals.
From domestic fuse board upgrades to commercial three-phase systems, our range ensures you stay compliant with Amendment 2 while keeping installs efficient and reliable. Every device is labelled, tested, and backed by a manufacturer warranty for peace of mind.
Three Phase 4 Pole Surge Protection Device WSPD440
£28.00
Full three-phase surge protection in a compact 4-module device. The WSPD440 is a high-performance 4 Pole Type 2 Surge Protection Device (SPD) for three-phase systems with neutral (3P+N). Rated up to 40kA discharge capacity, it protects against transient overvoltages from lightning strikes, switching surges, and...
RCD Upgrade Unit – 40A 2 Module with Seal Screws (WECRC40)
£16.65
The WECRC40 is a compact RCD upgrade unit pre-fitted with a 40A 30mA RCD inside a 2-module plastic enclosure. Designed for retrofitting where existing consumer units lack integrated RCD protection, it provides reliable earth leakage fault protection without requiring a full board replacement. Ideal for...
Main Switch Consumer Unit – WME04/MS100 (4 Module, 100A)
£23.30
The WME04/MS100 Main Switch Consumer Unit is a compact 4-module metal enclosure supplied with a 100A main switch incomer. Designed for small domestic installs, garages, and outbuildings, it provides 2 usable ways ready for population with MCBs or RCBOs. Finished in white powder-coated steel, with...
IP65 Plastic Pen Fault Detection Unit with Load Balancing Relay
£149.50
The IP65 PEN Fault Detection Unit with Load Balancing Relay is a regulation-ready solution for EV charger installations where PEN fault protection is mandatory. Fully compliant with BS7671:2018 Amendment 2, it isolates Live, Neutral, and Earth conductors during a fault – removing the need for...
RCD Upgrade Unit – 100A 2 Module with Seal Screws (WECRC100)
£16.65
The WECRC100 is the highest-rated model in our RCD upgrade unit range, pre-fitted with a 100A 30mA RCD inside a 2-module plastic enclosure. It provides reliable residual current and earth fault protection where consumer units or distribution boards lack integrated RCD cover. Engineered for heavy-duty...
What Are Circuit Protection Devices?
Every installation needs the right circuit protection to keep people and property safe. Under the 18th Edition Wiring Regulations, devices such as MCBs, RCDs, and RCBOs each play a specific role in protecting circuits against overload, short circuits, and earth leakage faults.
Main Device Types
- MCBs – trip on overload or short circuit to protect wiring.
- RCDs – disconnect supply when earth leakage is detected, reducing electric shock risk.
- RCBOs – combine MCB and RCD functions in one device, now standard for new installs.
- High Immunity RCBOs – designed to resist false tripping in EV, solar, and UPS circuits.
- Type B RCDs – DC-sensitive protection for EV chargers, heat pumps, and renewables.
- AFDD RCBOs – detect dangerous arc faults that standard devices can’t, recommended in HMOs and rental properties.
Compliance & Standards
All devices in this category are BS EN certified and meet the requirements of the 18th Edition Amendment 2. Selecting the correct protection ensures installations pass inspection, remain insurable, and safeguard against electrical hazards.
Applications
- Domestic boards – RCBOs and RCDs are standard for new builds and upgrades.
- Commercial installs – C-curve MCBs, three-phase RCBOs, and selective RCDs for grouped circuits.
- EV & renewable systems – Type B RCDs, high immunity RCBOs, and SPDs are strongly recommended.
Why Buy From Power & Data UK?
We stock the full spectrum of circuit protection devices, all with next-day delivery, hassle-free returns, and full manufacturer warranties. Every breaker is clearly labelled and tested for professional use, giving installers confidence on every job.