Type B RCDs for EV, Solar & DC Fault Protection
Type B RCDs are designed to detect smooth DC residual currents – making them essential for EV chargers, heat pumps, solar inverters, UPS systems, and other inverter-driven equipment. Unlike Type A or AC devices, Type B models protect against the full spectrum of fault currents, including high-frequency leakage.
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These devices are mandatory under IEC 62423 for certain installations and are recognised by the 18th Edition Wiring Regulations as the correct choice where DC leakage is possible. We stock both 2-pole and 4-pole Type B RCDs, suitable for single-phase and three-phase installs.
- DC detection built-in – smooth DC and high-frequency leakage
- Compliant with IEC 62423 – UK and EU recognised standard
- 2P & 4P options – for single and three-phase systems
- EV & renewables ready – trusted for chargers, solar, UPS and heat pumps
Need PME fault disconnection too? See our PME fault detection boards. For shipping and returns, visit our delivery information or returns policy.
Heat Pump RCD -B Type 2 Pole - WHP240-030
£125.00
The WHP240-030 is a compact Type B RCD specifically designed for heat pump systems – including Vaillant and other inverter-driven installs where full DC fault protection is required. Unlike Type A or Type AC RCDs, this 2 pole device is engineered to detect smooth DC...
2 Pole B Type RCDs
£125.00
The WCED WEV2 Series B-Type RCD provides advanced protection against smooth DC residual fault currents, as well as AC and pulsating DC faults up to 1000Hz. Fully compliant with IEC/EN 62423, it’s the correct choice for EV chargers, solar PV inverters, UPS systems, high-frequency converters,...
WME06/SP-B10063 - 6 Way Metal Unit with 100A B Type RCD & 63A MCB
£124.50
The WME06/SP-B10063 is a compact 6 module steel enclosure pre-assembled with a 100A B-Type RCD and 63A MCB. Built to order, this unit is designed to provide a ready-to-fit protection solution for EV installs, surge protection upgrades, or small distribution requirements. Housed in a robust...
IP65 Weatherproof Enclosure EV Kit with 63A B-Type RCD + 40A C MCB
£135.97
This IP65-rated Weatherproof Enclosure Kit includes a 63A B-Type RCD and a 40A C Curve MCB — making it ideal for electric vehicle (EV) and solar installations where smooth DC leakage detection is required. Designed to meet 18th Edition Amendment 2 regulations, it provides full...
4 Pole B-Type RCDs
£158.30
The WCED 4 Pole Type B RCD is designed to provide advanced protection for circuits where smooth DC and high-frequency fault currents are present. Fully compliant with IEC/EN 62423, it safeguards against AC, pulsating DC, and smooth DC residual currents up to 1000 Hz –...
Why Choose a Type B RCD?
A Type B RCD is required whenever there’s a risk of DC residual currents. Standard Type A or AC RCDs cannot reliably detect smooth DC faults, meaning they may fail to trip in critical fault conditions. For this reason, Type B RCDs are now the standard for many renewable and EV installs.
Applications
- EV chargers – compliance with BS 7671 & manufacturer requirements. Popular choice: B-Type RCD EV Kit with pre-wired protection.
- Solar inverters – protection against DC leakage and high-frequency harmonics. See the 2-Pole B-Type RCD for domestic installs.
- Heat pumps – inverter-driven compressors need DC-sensitive protection. For higher loads, use the 4-Pole B-Type RCD.
- UPS systems & drives – frequency converters and industrial systems benefit from stable DC fault detection.
Regulatory Compliance
Type B RCDs meet IEC 62423 and are recognised by the 18th Edition Wiring Regulations. Many EV and renewable equipment manufacturers specifically mandate their use to ensure warranty and insurance compliance.
FAQs on Type B RCDs
When do I need a Type B RCD?
Whenever there is inverter-driven equipment such as EV chargers, solar PV, or heat pumps. If smooth DC leakage is possible, a Type B device is mandatory.
Can I use a Type A RCD instead?
No – Type A RCDs only detect AC and pulsed DC. They may fail under smooth DC fault conditions, which is why Type B is required for compliance.
Are Type B RCDs more expensive?
Yes – but they provide wider protection. Installing the wrong type could cause a failed inspection, equipment damage, or safety risks.
Why Buy From Power & Data UK?
Our Type B RCDs are BS EN & IEC certified, backed by a 2-year manufacturer warranty, and shipped from our UK warehouse with next-day delivery on orders over £30. If you need to return an item, see our returns policy.