6kA MCB – 63A 1 Pole B Curve (WMC163B)
£1.84
£2.99
18th Ed. Compliant
2-Year Warranty
UK Stock
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The WMC163B is a 63 A single-pole 6 kA Miniature Circuit Breaker (MCB) built for high-load distribution circuits, feed boards and plant equipment. It delivers accurate overcurrent and short-circuit protection using a B-curve tripping profile (3–5 × In), providing fast disconnection on faults without nuisance tripping on steady loads. Tested...
The WMC163B is a 63 A single-pole 6 kA Miniature Circuit Breaker (MCB) built for
Tested and certified to BS EN 60898, the WMC163B fits all Whitecliffe consumer units and standard 35 mm DIN-rail enclosures. Its 6 kA breaking capacity and 20 000-cycle mechanical life make it a dependable choice for large sub-mains and industrial feed applications requiring regulation-compliant protection.
Installer Tip: Use 63 A B-curve devices for main feed circuits or distribution board supplies drawing up to around 14 kW (single phase). Verify cable size, voltage drop and Zs values before energising to ensure BS 7671 compliance.
- 63 A rated current with B-curve (3–5 × In) tripping characteristic
- 6 kA breaking capacity at 230/400 V AC
- Single-pole design – 18 mm module width
- DIN-rail mounted for consumer units and distribution boards
- Complies with BS EN 60898 and BS 7671 (18th Edition A2)
- Service life: 20 000 mechanical / 8 000 electrical operations
- Front contact indicator for clear on/off status
| Part Code | Rating | Curve | Typical Use |
|---|---|---|---|
| WMC150B | 50 A | B | Feed circuits and plant equipment |
| WMC163B | 63 A | B | Large distribution feeds and industrial loads |
| WMC163C | 63 A | C | Motors, compressors or inrush-heavy equipment |
The WMC163B delivers robust 6 kA fault protection for main feed and distribution circuits. For circuits with motors or transformer inrush, use our C Curve MCB range or upgrade to Type A RCBOs for combined overcurrent and earth-fault protection.
Where is a 63 A B Curve MCB used?
Typically on main feed circuits or sub-distribution boards where loads are steady and continuous. Provides fast fault clearing at 3–5 × In.
Is the WMC163B compatible with Whitecliffe boards?
Yes – it fits all Whitecliffe consumer units and standard 18 mm DIN-rail enclosures.
Can it be used for industrial feed applications?
Yes, provided the fault level does not exceed 6 kA and the cables and enclosure are rated appropriately. For outdoor use, select an IP65 plastic enclosure.
When should I use a C Curve MCB instead?
Choose a C Curve MCB for circuits feeding motors or transformers with high inrush currents that could trip a B-curve device.
What does 6 kA mean?
6 kA is the maximum fault current the MCB can interrupt without damage. For sites with higher prospective fault currents, see our 10 kA MCB range.
- Part Code: WMC163B
- Type: Single Pole MCB
- Rated Current (In): 63 A
- Curve: B (3–5 × In tripping characteristic)
- Rated Voltage (Ue): 230/400 V AC
- Rated Frequency: 50/60 Hz
- Breaking Capacity (Icn): 6 kA
- Insulation Voltage (Ui): 500 V
- Impulse Withstand (Uimp): 4 kV
- Dielectric Test Voltage: 2 kV for 1 minute
- Thermal Reference Temp: 30 °C
- Operating Temperature: –5 °C to +40 °C (avg < 35 °C)
- Mechanical Life: 20 000 operations
- Electrical Life: 8 000 operations
- Mounting: 35 mm DIN rail (1 module width)
- Standards: BS EN 60898; BS 7671:2018 (Amendment 2)
- Typical Applications: Main feeds, distribution boards and high-load equipment circuits
Install the WMC163B in a suitable consumer unit or distribution board by a qualified electrician. Ensure the rating and curve match the circuit design and upstream device.
- Mount securely on 35 mm DIN rail and verify busbar alignment
- Use B-curve for steady-load feed and distribution circuits
- Confirm cable size, Zs and voltage drop comply with BS 7671
- Use C-curve for motors or high inrush loads
- Tighten terminals to manufacturer torque spec and record results
