40A 2 Pole 10kA MCB – D Curve (WKC240D)
18th Ed. Compliant
2-Year Warranty
UK Stock
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The WKC240D is a 40 A 2 Pole 10 kA Miniature Circuit Breaker (MCB) designed for high-demand applications such as HVAC plant, industrial machinery, and feeder circuits. Its D-curve tripping profile accommodates up to 20× rated current during startup, making it ideal for motors, compressors, and other inductive loads. Built...
The WKC240D is a 40 A 2 Pole 10 kA Miniature Circuit Breaker (MCB) designed for high-demand applications such as HVAC plant, industrial machinery, and feeder circuits. Its D-curve tripping profile accommodates up to 20× rated current during startup, making it ideal for motors, compressors, and other inductive loads.
Built for reliability in commercial and industrial environments, the MCB provides simultaneous isolation of both live conductors and conforms to BS EN 60898-1. Compact 36 mm housing allows easy installation on standard 35 mm DIN rails in metal enclosures, distribution boards, and consumer units.
Installer Tip: A 40 A D-curve MCB is best used for HVAC systems, heavy feeders, or plant machinery with significant inrush current. For moderate inductive loads, consider the C-curve version.
Key Features
- 40 A rated – suited for HVAC, machinery, and feeder circuits
- 10 kA breaking capacity – built for high commercial fault levels
- 2-pole isolation – disconnects both live conductors at once
- D-curve tripping – handles 10–20× inrush current at start-up
- Bi-directional terminals – top or bottom feed installation
- 36 mm (2-module) DIN-rail body for compact fit
- Conforms to IEC/EN 60898-1 and 18th Edition Wiring Regulations
Compare 2 Pole 10 kA MCB Variants
| Model | Rating | Curve |
|---|---|---|
| WKC240B | 40 A | B Curve |
| WKC240C | 40 A | C Curve |
| WKC240D (This Product) | 40 A | D Curve |
What is a 40 A D-curve MCB used for?
Ideal for HVAC, compressors, and plant equipment where high inrush current occurs at startup.
Does it disconnect both conductors?
Yes – 2-pole design isolates both live lines simultaneously for full safety compliance.
Can this be used on industrial feeder circuits?
Yes – suitable for feeder supplies and control panels requiring high inrush tolerance.
Is it 18th Edition compliant?
Yes – fully tested to BS EN 60898-1 and approved for 18th Edition installations.
- Model: WKC240D
- Poles: 2
- Rated Current: 40 A
- Curve Type: D
- Breaking Capacity: 10 kA
- Operating Voltage: 230/400 V AC
- Mounting: 35 mm DIN rail (EN 60715)
- Width: 36 mm (2 modules)
- Standard: IEC/EN 60898-1
- Applications: HVAC units, plant equipment, feeder sub-circuits
Install by a qualified electrician in accordance with BS 7671. Confirm that the load type requires a D-curve device and check cable sizing prior to energising.
- Mount on 35 mm DIN rail (EN 60715)
- Torque terminals to 2.0–2.5 Nm
- Check insulation resistance and polarity before connection
- Label protected circuits clearly on the distribution schedule
