40A 4 Pole 10kA MCB B Curve – WKC440B
18th Ed. Compliant
2-Year Warranty
UK Stock
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The WKC440B is a 40A 4 pole 10kA Miniature Circuit Breaker (MCB) for three-phase + neutral circuits. With its B Curve trip characteristic, this breaker is intended for resistive load circuits such as socket outlet banks, small distribution boards, and lighting groups in commercial three-phase systems, EV distribution boards, and...
The WKC440B is a 40A 4 pole 10kA Miniature Circuit Breaker (MCB) for three-phase + neutral circuits. With its B Curve trip characteristic, this breaker is intended for resistive load circuits such as socket outlet banks, small distribution boards, and lighting groups in commercial three-phase systems, EV distribution boards, and solar PV installs.
With a 10kA breaking capacity, the WKC440B delivers safe overload and short-circuit protection while disconnecting all phases and neutral. It is DIN-rail mounted, bi-directional, and manufactured in compliance with BS 7671 (18th Edition).
Installer Tip: The 40A B Curve breaker is a solid choice for larger socket outlet circuits or small commercial distribution boards. Verify that the installation fault current does not exceed 10kA before use.
Key Features
- 40A 4 Pole MCB – B Curve trip characteristic
- 10kA breaking capacity – reliable in commercial & industrial installs
- Full neutral protection: 4P switching (L1, L2, L3, N)
- Bi-directional feed: top or bottom cable entry
- DIN-rail mountable: 18mm width per module
- Complies with BS 7671 (18th Edition)
Compare WKC 4 Pole 10kA MCBs (B Curve)
| Model | Rating | Curve | Breaking Capacity |
|---|---|---|---|
| WKC432B | 32A | B Curve | 10kA |
| WKC440B (This Product) | 40A | B Curve | 10kA |
| WKC450B | 50A | B Curve | 10kA |
| WKC463B | 63A | B Curve | 10kA |
What applications is the WKC440B best for?
It’s suited to larger socket outlet groups and small commercial distribution boards with resistive loads.
Why use a 4-pole MCB instead of 3-pole?
It isolates the neutral as well as all three phases, ensuring full protection in three-phase + N circuits.
Can the WKC440B be used in EV or solar installs?
Yes, where the load is resistive and fault levels are ≤10kA. For inductive loads, choose a C Curve alternative.
Is the WKC440B regulation compliant?
Yes — it complies with BS 7671 (18th Edition) and IEC/EN 60898-1.
- Model: WKC440B
- Type: Miniature Circuit Breaker (MCB)
- Current Rating: 40A
- Curve: B Curve
- Poles: 4P (L1, L2, L3 + Neutral)
- Breaking Capacity: 10kA
- Mounting: 35mm DIN rail, 18mm per module
- Dimensions: Approx. 72mm (W) x 90mm (H) x 77mm (D)
- Standards: BS 7671 (18th Edition), IEC/EN 60898-1
- Brand: WCED
Installation of the WKC440B must be performed by a qualified electrician in line with BS 7671 wiring regulations.
- Mount on 35mm DIN rail (18mm per pole)
- Ensure fault current ≤10kA
- Designed for resistive loads only (B Curve)
- Tighten terminals to manufacturer torque spec
- Confirm space in enclosure for 4P devices
