RCDs – Residual Current Devices
Residual Current Devices (RCDs) protect against earth leakage faults and electric shock, making them a core part of every 18th Edition installation. Choose from Type A or Type AC RCDs in 30mA or 100mA sensitivities, or step up to Type B RCDs for DC-sensitive installs like EV and solar.
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All RCDs in this range meet BS EN 61008 and 61009 standards and are suitable for both residential and commercial use. They disconnect supply immediately if leakage is detected, protecting against electric shock and reducing fire risk.
- Type A RCDs – detect AC and pulsed DC leakage, now the UK standard for most new installs
- Type AC RCDs – detect AC leakage only, being phased out in many applications
- 30mA sensitivity – personal protection for final circuits
- 100mA sensitivity – time-delayed or selective protection in larger installs
Need combined overload and leakage protection? View our RCBO range. For shipping details, see our delivery information or returns policy.
Heat Pump Consumer Unit 8 Way (WME08/HP40C)
£187.80
Pre-wired in the UK and tested before dispatch – allow up to 3 working days for shipping. The WME12/HP40C Heat Pump Consumer Unit is a dedicated 12-way protection board designed for inverter-driven heat pump systems. It comes pre-fitted with a 40A Type B RCD, a...
Heat Pump Consumer Unit 12 Way (WME12/HP40C)
£147.80
Pre-wired in the UK and tested before dispatch – allow up to 3 working days for shipping. The WME08/HP40C Heat Pump Consumer Unit is a dedicated protection board for inverter-driven heat pump systems. It comes pre-fitted with a 40A Type B RCD, a 40A Type...
4 Pole B-Type RCD – WEV440B-030 (40A, 30mA)
£158.30
The WEV440B-030 is a 4 Pole Type B RCD (40A, 30mA) designed for circuits where smooth DC or high-frequency leakage currents may be present. Unlike Type A RCDs, it detects AC, pulsed DC, and smooth DC residual currents up to 1000 Hz, ensuring safe disconnection...
A Type Time Delay RCD – 63A 100mA, 2 Pole (WARTD263-100)
£25.35
The WARTD263-100 A-Type 100mA Time Delay RCD is a 2 Pole S-Type device designed for upstream fault protection in dual-RCD or selective coordination setups. With its built-in delay, it ensures that downstream devices trip first, maintaining supply integrity across unaffected circuits. Ideal for EV charging...
A Type Time Delay RCD – 63A 100mA, 4 Pole (WARTD463-100)
£30.25
The WARTD463-100 A-Type 100mA Time Delay RCD is a 4 Pole S-Type device rated at 63A. Its built-in time delay ensures upstream discrimination, allowing downstream RCDs to trip first and preventing unnecessary power loss. Ideal for three-phase distribution boards, EV charging hubs, and renewable installs...
What Is an RCD?
An RCD (Residual Current Device) is a protective switch that cuts power if it detects current leaking to earth. This protects against electric shock and reduces the risk of fire caused by faulty wiring or appliances. Under the 18th Edition Wiring Regulations, RCDs are mandatory on most final circuits in the UK.
Types of RCDs
- Type A – detects both AC and pulsed DC leakage. Recommended for modern appliances, EV chargers, and heat pumps. Example: 2-Pole A-Type 100mA Time Delay RCD.
- Type AC – detects AC leakage only. Still in use but no longer recommended for new domestic installs.
- Type B – DC-sensitive devices for EVs, solar, and heat pumps. See our Type B RCD category.
- Type F – specialist for variable frequency drives and sensitive electronics.
Sensitivity & Ratings
RCDs are available in different ratings to suit their application:
- 30mA – provides personal protection against electric shock, required on most socket and lighting circuits.
- 100mA – typically used for fire protection or selective time-delayed devices in larger installs.
- 300mA+ – used in industrial or commercial systems for equipment/fire protection.
FAQs on RCDs
What’s the difference between an RCD and an RCBO?
An RCD only protects against earth leakage. An RCBO combines RCD and MCB protection in one device.
Are Type AC RCDs still allowed in the UK?
Yes, but Type A RCDs are now strongly preferred under the 18th Edition due to the growing use of electronics and inverter-driven equipment.
How often should RCDs be tested?
They should be tested every 3 months using the “test” button, and formally checked at each EICR or inspection.
Why Buy From Power & Data UK?
All RCDs we supply are BS EN certified, backed by manufacturer warranties, and shipped directly from our UK warehouse. Orders over £30 qualify for free next-day delivery, with optional Saturday upgrades available. Need to send something back? See our returns policy.
Explore Related Categories
- RCBOs – combined protection devices
- High Immunity RCBOs – prevent nuisance trips
- Type B RCDs – DC-sensitive protection
- Circuit Protection – MCBs, RCDs & breakers
- Surge Protection Devices (SPDs)