WKC 3 Pole 10kA MCB – 40A B Curve (WKC340B)
The WKC340B 3 Pole 10kA MCB is a 40A B Curve breaker providing short-circuit and overload protection for three-phase circuits. Built with a 10kA breaking capacity and full compliance with BS 7671 (18th Edition), it’s trusted in industrial boards, EV charging setups, and solar PV systems. Compact, DIN rail mountable,...
Read full descriptionThe WKC340B 3 Pole 10kA MCB is a 40A B Curve breaker providing short-circuit and overload protection for three-phase circuits. Built with a 10kA breaking capacity and full compliance with BS 7671 (18th Edition), it’s trusted in industrial boards, EV charging setups, and solar PV systems. Compact, DIN rail mountable, and bi-directional, it delivers safe and reliable disconnection in demanding environments.
Installer Tip: Choose the B Curve for resistive loads such as lighting and socket circuits. For inductive or high inrush loads, see the C Curve or D Curve variants.
Key Features
- 40A rated current – suited for heavier three-phase loads
- B Curve tripping – rapid fault clearance for resistive circuits
- 10kA breaking capacity – safe operation under high fault levels
- 3 Pole design: protection across all three phases
- Bi-directional: top or bottom wiring accepted
- Applications: industrial boards, lighting, sockets, EV/PV circuits
Compare 40A 3 Pole Variants
| Model | Curve | Rated Current | Breaking Capacity |
|---|---|---|---|
| WKC340B (This Product) | B Curve | 40A | 10kA |
| WKC340C | C Curve | 40A | 10kA |
| WKC340D | D Curve | 40A | 10kA |
Where should the WKC340B be installed?
It’s ideal for commercial and industrial boards protecting 40A resistive three-phase loads such as lighting and socket circuits.
What’s the difference between B, C, and D Curves?
B Curve trips at 3–5x In (resistive loads). C Curve trips at 5–10x In for inductive loads. D Curve trips at 10–20x In for high inrush equipment.
Why choose a 10kA MCB?
It ensures safe interruption under fault levels up to 10,000A, making it suitable for most commercial and industrial installs.
Is it bi-directional?
Yes — the breaker can be wired from top or bottom.
Is this breaker EV and PV compatible?
Yes — widely used in EV charger protection and solar PV boards.
- Product Code: WKC340B
- Type: Miniature Circuit Breaker (MCB)
- Poles: 3P (three-phase)
- Rated Current: 40A
- Curve: B Curve
- Breaking Capacity: 10kA
- Mounting: DIN rail, 18mm per module
- Functions: Overload & short-circuit protection, switching, isolation
- Compliance: BS 7671 (18th Edition)
- Endurance: 4000 mechanical / 2000 electrical operations
- Brand: WCED
Mount on a DIN rail inside consumer units or distribution boards. Select curve based on application:
- B Curve: resistive circuits such as lighting or sockets
- C Curve: inductive circuits (motors, HVAC, EV chargers)
- D Curve: heavy inrush loads (transformers, welders)
Verify that the installation’s fault level is within the 10kA capacity. All installations must follow BS 7671 and be carried out by a qualified electrician.
