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 16A C Curve WRN16C-030
£15.17
The WRN16C-030 is a 16A Type A RCBO with a C-curve tripping characteristic, supplied in a compact single-module, 2-pole design. It combines residual current (RCD) and overcurrent (MCB) protection in one device, detecting AC and pulsating DC leakage currents. With a switched neutral included, it...
Type A RCBO – 50A C Curve, 30mA
£12.50
The WRT150C-030 is a 50A C Curve Type A RCBO designed for heavy-duty domestic and commercial circuits. It combines overcurrent and 30mA residual current protection in one slim 18mm device, with switched live and neutral disconnection for full isolation, bi-directional wiring for solar PV and...
Type A RCBO – 40A C Curve, 30mA
£12.50
The WRT140C-030 is a 40A C Curve Type A RCBO designed for circuits with high inrush current, such as EV chargers, motors, and heat pumps. It provides both overcurrent and 30mA residual current protection in a single device, with switched live and neutral disconnection for...
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.