Type A RCBO – 40A B Curve, 30mA
18th Ed. Compliant
2-Year Warranty
UK Stock
Free Delivery £30+
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The WRT140B-030 is a 40A B Curve Type A RCBO that delivers overcurrent and 30mA residual current protection in one compact device. Featuring switched live and neutral disconnection for full circuit isolation, high immunity electronics to resist nuisance tripping, and bi-directional wiring for flexible use in solar PV, EV charging,...
The WRT140B-030 is a 40A B Curve Type A RCBO that delivers overcurrent and 30mA residual current protection in one compact device. Featuring switched live and neutral disconnection for full circuit isolation, high immunity electronics to resist nuisance tripping, and bi-directional wiring for flexible use in solar PV, EV charging, and inverter-fed systems.
Fully compliant with the 18th Edition Wiring Regulations (Amendment 2) and tested to IEC/EN 61009-1, this RCBO is a robust solution for domestic and commercial circuits requiring 40A protection.
Installer Tip: Use the B Curve for general lighting and socket circuits with low inrush current. For EV chargers, heat pumps, and motors with higher start-up demand, select the C Curve version.
Key Features
- 40A B Curve Type A RCBO – overload + residual current protection
- Switched live & neutral – safe fault isolation
- High immunity design – resists nuisance trips from harmonics
- Bi-directional wiring – ideal for inverter-fed and renewable systems
- Compact 18mm module – fits standard consumer units
- 10kA breaking capacity – built for domestic & commercial installs
- Conforms to IEC/EN 61009-1
Compare WRT Range
| Model | Rating | Curve | Application |
|---|---|---|---|
| WRT132B-030 | 32A | B Curve | Consumer Units / General Loads |
| WRT140B-030 (This Product) | 40A | B Curve | Domestic / Commercial Loads |
| WRT140C-030 | 40A | C Curve | EV / Motors / Heat Pumps |
| WRT150B-030 | 50A | B Curve | Higher Load Circuits |
When should I use a 40A RCBO?
For higher load domestic or commercial circuits requiring 40A overload protection with residual current safety.
What’s the benefit of Type A?
Type A RCBOs detect pulsating DC as well as AC leakage, making them suitable for EV chargers, solar, and modern electronic appliances.
Does it fully isolate the circuit?
Yes – switched live and neutral poles disconnect both conductors safely.
Why high immunity?
It prevents nuisance trips caused by harmonics and switching surges, especially in inverter-fed systems.
- Type: A (AC + pulsating DC detection)
- Rating: 40A
- Trip Curve: B
- Sensitivity: 30mA
- Breaking Capacity: 10kA
- Poles: 1P+N (switched live + neutral)
- Voltage: 230V AC
- Impulse Withstand: 4kV
- Electrical Life: 2,000 operations
- Mechanical Life: 10,000 operations
- Protection Degree: IP20
- Terminal Capacity: Top 10mm² / Bottom 16mm²
- Dimensions: W17.8 × H116 × D76mm
- SKU: WRT140B-030
- Standards: IEC/EN 61009-1
Built for 40A circuits in domestic and commercial boards. Provides overload, short-circuit, and earth leakage protection with high immunity against nuisance trips.
- DIN rail mounted – single 18mm module
- Ensure 40A rating matches circuit demand
- Bi-directional wiring allows flexible line/load install
- Must be fitted by a qualified electrician
