High Immunity RCBO – 40A B Curve, Type A, 30mA (WER40B-030)
18th Ed. Compliant
2-Year Warranty
UK Stock
Free Delivery £80+
Secure Payments With
The WER40B-030 is a 40A B Curve High Immunity Type A RCBO designed for heavier duty residential and commercial circuits, including solar PV, battery storage, and EV-ready consumer units. It combines overload, short-circuit, and 30mA residual current protection with enhanced resistance to nuisance tripping caused by harmonics or transient voltages....
The WER40B-030 is a 40A B Curve High Immunity Type A RCBO designed for heavier duty residential and commercial circuits, including solar PV, battery storage, and EV-ready consumer units. It combines overload, short-circuit, and 30mA residual current protection with enhanced resistance to nuisance tripping caused by harmonics or transient voltages.
With double pole disconnection and bi-directional wiring, this RCBO provides full compliance with the 18th Edition Wiring Regulations (Amendment 2) and safe operation in inverter-fed systems.
Installer Tip: The B Curve is suited for standard circuits with lower inrush currents. For EV chargers, motors, or heat pumps, use the C Curve version of this device.
Key Features
- 40A B Curve Type A RCBO – protects against overload and earth leakage
- High immunity electronics – resists nuisance trips
- 30mA sensitivity – compliant with Amendment 2
- 10kA breaking capacity – built for residential & commercial installs
- Double pole disconnection – isolates live + neutral conductors
- Bi-directional wiring – install either way round
- Meets BS EN 61009 & 18th Edition Wiring Regulations
Compare High Immunity RCBOs
| Model | Rating | Curve | Typical Use |
|---|---|---|---|
| WER06B-030 | 6A | B | Lighting and other low inrush final circuits |
| WER06C-030 | 6A | C | Low-rated circuits where higher inrush tolerance is preferred |
| WER16B-030 | 16A | B | General domestic final circuits with low inrush loads |
| WER16C-030 | 16A | C | Small motors and circuits with moderately higher inrush current |
| WER20B-030 | 20A | B | Domestic final circuits requiring a higher current rating |
| WER20C-030 | 20A | C | Circuits with moderately higher inrush current |
| WER32B-030 | 32A | B | Ring finals and other standard appliance circuits |
| WER32C-030 | 32A | C | Higher demand circuits and loads with greater inrush current |
| WER40B-030 (This Product) | 40A | B | Higher load circuits with lower inrush characteristics |
| WER40C-030 | 40A | C | Heavier-duty circuits with higher inrush conditions |
| WER63C-030 | 63A | C | Larger commercial or high-load applications |
When should I specify a 40A RCBO?
Use for higher rated residential or commercial circuits requiring 40A overload protection with earth leakage monitoring.
Is this suitable for EV chargers?
B Curve RCBOs can be used, but C Curve versions are recommended for most EV charge points due to inrush current.
Does it offer high immunity?
Yes – this unit is engineered to resist false trips caused by harmonics or switching surges.
Does it disconnect live and neutral?
Yes – it provides full double pole disconnection for safety and compliance.
- Type: A (detects AC + pulsating DC leakage)
- Rating: 40A
- Trip Curve: B
- Sensitivity: 30mA
- Breaking Capacity: 10kA
- Poles: 2 (double pole disconnection)
- Wiring: Bi-directional
- SKU: WER40B-030
- Standards: BS EN 61009 / IEC 61009
Designed for consumer units and distribution boards requiring 40A B Curve protection. Especially suited for heavier duty circuits in residential or commercial installs with inverter-fed loads.
- Mounts directly to DIN rail
- Confirm circuit demand matches 40A rating
- Bi-directional wiring simplifies installation
- Qualified electrician installation required
