Type A RCBO – 20A B Curve, 30mA
18th Ed. Compliant
2-Year Warranty
UK Stock
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The WRT120B-030 is a 20A B Curve Type A RCBO that combines overcurrent and residual current protection in a single compact device. Featuring switched live and neutral disconnection for full isolation, bi-directional wiring for solar and EV applications, and a high immunity design to minimise nuisance tripping, it’s a versatile...
The WRT120B-030 is a 20A B Curve Type A RCBO that combines overcurrent and residual current protection in a single compact device. Featuring switched live and neutral disconnection for full isolation, bi-directional wiring for solar and EV applications, and a high immunity design to minimise nuisance tripping, it’s a versatile choice for domestic and light commercial installs.
This RCBO detects both AC faults and pulsating DC leakage currents, ensuring compliance with the 18th Edition Wiring Regulations (Amendment 2). Its slim, single-module profile makes it ideal for consumer units where space is limited.
Installer Tip: The B Curve is suited for general lighting and socket circuits with low inrush current. For motors, EV chargers, or heat pumps, use the C Curve model instead.
Key Features
- 20A B Curve Type A RCBO – overload + earth leakage protection
- Switched live & neutral – safe isolation of faulty circuits
- High immunity design – prevents nuisance trips in noisy environments
- Bi-directional wiring – compatible with solar PV and inverter-fed systems
- Compact 18mm module – saves space in consumer units
- 10kA breaking capacity – reliable for residential and commercial use
- Conforms to IEC/EN 61009-1
Compare WRT Range
| Model | Rating | Curve | Application |
|---|---|---|---|
| WRT116B-030 | 16A | B Curve | Domestic / General Circuits |
| WRT120B-030 (This Product) | 20A | B Curve | Domestic / Light Commercial |
| WRT120C-030 | 20A | C Curve | Motors / EV / Heat Pumps |
| WRT125B-030 | 25A | B Curve | Higher Load Circuits |
When should I use a 20A RCBO?
It’s suitable for domestic and small commercial circuits requiring 20A protection with residual current monitoring.
Why Type A over AC?
Type A RCBOs detect pulsating DC as well as AC leakage, which is essential for EV chargers, solar inverters, and modern electronics.
Does it disconnect both poles?
Yes – live and neutral are both isolated on trip for safe testing and compliance.
What is the benefit of high immunity?
It helps prevent nuisance trips caused by harmonics, switching surges, and inverter-fed equipment.
- Type: A (detects AC + pulsating DC leakage)
- Rating: 20A
- 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: WRT120B-030
- Standards: IEC/EN 61009-1
Designed for consumer units and distribution boards requiring 20A overload and residual protection. Particularly suited for domestic boards, small commercial installs, and renewable energy systems.
- DIN rail mounted – 18mm single module
- Ensure rating matches circuit demand
- Bi-directional wiring simplifies install
- Install only by a qualified electrician
