C Curve RCBOs for High-Inrush & Motor-Driven Circuits
C Curve RCBOs are designed for circuits with higher inrush currents, such as motors, compressors, machinery, pumps, power tools and certain EV or renewable system components. They provide combined overcurrent and earth-leakage protection in one device, while allowing for short, controlled startup surges without nuisance tripping.
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These RCBOs operate within the C-curve tripping band, giving them tolerance for initial current spikes of five to ten times the rated current. They are commonly used in properties with high-load appliances, workshops, small commercial settings and inverter-driven equipment. Most models include switched neutrals, compact modules and Type A sensitivity for modern loads.
- Combined MCB + RCD protection for full circuit coverage
- C-curve tripping characteristics for high-inrush circuits
- Type A sensing to detect AC and pulsed DC leakage
- Switched neutral designs for improved testability and safety
- Wide range of ratings from 6A to 50A for diverse applications
Installers choose C Curve RCBOs for circuits that need robust overcurrent protection without unnecessary disconnections during appliance startup. All ratings, dimensions and characteristics are detailed within each individual product listing.
Single Module 2 Pole RCBO 20A C Curve WRN20C-030
£15.17
The WRN20C-030 is a 20A Type A RCBO with a C-curve tripping characteristic, designed in a compact single-module, 2-pole format. It combines residual current (RCD) and overcurrent (MCB) protection in one device, detecting both AC and pulsating DC leakage currents. The switched neutral ensures complete...
High Immunity Type A Mini RCBO – 20A C Curve (WRB120C-030)
£11.67
The WRB120C-030 High Immunity Type A Mini RCBO is a 20A C Curve protective device designed for circuits with higher inrush currents. Compact at just 18mm wide, it combines short-circuit, overload, and residual current protection in one unit. With 30mA Type A sensitivity and high...
High Immunity RCBO – 20A C Curve, Type A, 30mA
£18.67
The WER20C-030 is a 20A C Curve High Immunity Type A RCBO designed for EV chargers, motors, heat pumps, and inverter-fed systems. It provides combined overload, short-circuit, and 30mA residual current protection, while high immunity electronics reduce nuisance tripping from harmonics and transient voltages. Featuring...
High Immunity RCBO – 16A C Curve, Type A, 30mA
£18.67
The WER16C-030 is a 16A C Curve High Immunity Type A RCBO built for EV chargers, motors, heat pumps, and inverter-fed systems. It provides overload, short-circuit, and 30mA residual current protection, while the high immunity design prevents nuisance tripping in circuits subject to harmonics and...
Type A RCBO – 32A C Curve, 30mA
£12.50
The WRT132C-030 is a 32A C Curve Type A RCBO combining overcurrent and residual current protection in a compact single-module device. It features switched live and neutral disconnection for full isolation, bi-directional wiring for solar PV and inverter systems, and high immunity electronics that reduce...
What Is a C Curve RCBO?
A C curve RCBO provides overcurrent, short-circuit and earth-leakage protection while accommodating higher initial current spikes. These devices trip between five and ten times their rated current, making them suitable for circuits with motors, compressors and load-heavy equipment.
Where C Curve RCBOs Are Used
- Heat pumps and HVAC systems with compressor inrush currents
- Workshops and garages using power tools or small machinery
- Industrial and semi-commercial equipment with motor start-up loads
- Renewable systems including hybrid inverters and battery setups
- High-load appliance circuits that regularly experience brief surge currents
Benefits of C Curve Protection
C curve devices are engineered to avoid nuisance tripping on equipment that naturally draws higher current at startup. They still provide rapid disconnect under genuine fault conditions, ensuring safe operation while supporting demanding loads.
- Stable performance under fluctuating or surge-prone loads
- Reduced nuisance trips on startup-heavy circuits
- Accurate fault clearing to protect wiring and equipment
Compliance & Standards
All C Curve RCBOs in this category comply with BS 7671 (18th Edition) and meet the performance and safety requirements of IEC/EN 61009. They are suitable for use in consumer units and distribution boards where higher load tolerance is required.
Selecting the Correct Rating
These RCBOs are available from 6A through to 50A, covering everything from small circuits to heavy appliance feeds. Choosing the correct rating depends on cable size, load characteristics and the installation environment. Matching both the rating and the curve to the equipment prevents nuisance tripping and ensures long-term circuit stability.
Installer Benefits
C Curve RCBOs offer enhanced surge tolerance, cleaner separation of circuits and reliable fault protection. Their compact design, switched neutrals and strong operating characteristics make them a dependable choice for both domestic and commercial setups requiring higher load handling.