WKC 3 Pole 10kA MCB – 20A D Curve (WKC320D)
18th Ed. Compliant
2-Year Warranty
UK Stock
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The WKC320D 3 Pole 10kA MCB is a 20A D Curve breaker engineered for three-phase circuits with heavy inrush currents. With a 10kA breaking capacity and full compliance with BS 7671 (18th Edition), it provides safe disconnection of overloads and short-circuits in demanding environments. This breaker is widely used for...
The WKC320D 3 Pole 10kA MCB is a 20A D Curve breaker engineered for three-phase circuits with heavy inrush currents. With a 10kA breaking capacity and full compliance with BS 7671 (18th Edition), it provides safe disconnection of overloads and short-circuits in demanding environments. This breaker is widely used for welders, transformers, compressors, and heavy plant machinery, where standard B or C Curve devices would nuisance trip.
Installer Tip: Choose D Curve breakers only for circuits with very high inrush demand. For resistive circuits, use the B Curve. For moderate inductive loads, the C Curve is more appropriate.
Key Features
- 20A rated current – ideal for medium three-phase circuits
- D Curve tripping – trips at 10–20x In
- 10kA breaking capacity – safe interruption of high fault levels
- 3 Pole protection: covers all three phases
- Bi-directional: wiring possible from top or bottom
- Applications: welders, compressors, transformers, heavy motors, plant machinery
Compare 20A 3 Pole Variants
| Model | Curve | Rated Current | Breaking Capacity |
|---|---|---|---|
| WKC320B | B Curve | 20A | 10kA |
| WKC320C | C Curve | 20A | 10kA |
| WKC320D (This Product) | D Curve | 20A | 10kA |
What is the WKC320D used for?
For protecting 20A three-phase circuits with very high inrush, such as welders, compressors, or industrial machinery.
How does D Curve compare with B and C?
B Curve trips at 3–5x In (resistive), C Curve at 5–10x In (inductive), while D Curve trips at 10–20x In for high inrush loads.
What does 10kA breaking capacity mean?
It’s the maximum short-circuit fault current the breaker can safely interrupt. 10kA ensures safe operation in commercial and industrial boards.
Is this breaker bi-directional?
Yes — can be wired from either top or bottom terminals.
Can this be used for EV or PV systems?
No — D Curve breakers are generally not required for EV or PV. They’re built for heavy plant and machinery with high inrush.
- Product Code: WKC320D
- Type: Miniature Circuit Breaker (MCB)
- Poles: 3P (three-phase)
- Rated Current: 20A
- Curve: D 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
Install inside distribution boards where circuits experience very high inrush. Curve choice is key:
- B Curve: lighting, sockets (resistive)
- C Curve: motors, HVAC, EV chargers (moderate inrush)
- D Curve: welders, transformers, compressors, industrial machinery (high inrush)
Always check the prospective fault current does not exceed 10kA. Installation must comply with BS 7671 and be carried out by a qualified electrician.
