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4 Way Metal Enclosure – 40A B Curve MCB + Surge Protection (WMKB240BSP)

£35.95 ex VAT £43.14 inc VAT

The WMKB240BSP is a compact 4 way metal enclosure pre-fitted with a 40A B Curve MCB and Type 2 Surge Protection Device (SPD). Built for EV charger supplies, outbuildings, and small sub-mains, it combines overload protection and surge defence in a durable steel housing. The 40A B Curve MCB makes...

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Description

The WMKB240BSP is a compact 4 way metal enclosure pre-fitted with a 40A B Curve MCB and Type 2 Surge Protection Device (SPD). Built for EV charger supplies, outbuildings, and small sub-mains, it combines overload protection and surge defence in a durable steel housing.

The 40A B Curve MCB makes this unit suitable for domestic EV installs, general distribution boards, and standard load circuits. With a pre-fitted Type 2 SPD, it ensures compliance with 18th Edition Amendment 2 and gives added resilience against transient overvoltages.

Installer Tip: Use the B Curve model for standard domestic circuits. If you expect higher inrush currents (motors, heat pumps, certain EV chargers), opt for the C Curve variant.

Key Features

  • 40A B Curve MCB – protection against overloads and short-circuits
  • Factory-fitted Type 2 SPD – compliance with 18th Edition surge protection requirements
  • 4 way steel enclosure – robust, compact, and durable
  • Supplied fully built – saves installation time
  • Complies with BS EN 61439-3

Compare 4 Way MCB + SPD Enclosure Variants

Model Rating Curve Protection
WMKB240BSP (This Product) 40A B MCB + SPD
WMKB240CSP 40A C MCB + SPD
Technical specs
  • Enclosure: 4 way steel housing, IP40
  • MCB: 40A, 2 module, B Curve
  • Surge Protection: Type 2 SPD, factory fitted
  • Operating Voltage: 230V AC, 50Hz
  • Standards: BS EN 61439-3
  • Build Time: 3 working days
Installation notes

This unit is supplied pre-built with MCB and SPD installed. A qualified electrician must complete final wiring and testing.

  • Fully assembled – no internal wiring required
  • Knockouts provided for flexible cable entry
  • Confirm breaker curve (B or C) matches load type
  • Install in a dry, accessible location with adequate ventilation
FAQs

Is this enclosure suitable for EV charger installs?

Yes. It is built for EV-ready supplies requiring a 40A breaker and Type 2 SPD. For other sizes, view our EV consumer unit range.

When should I use B Curve vs C Curve?

B Curve MCBs suit domestic/general loads, while C Curve options handle higher inrush currents (e.g. motors, certain EV chargers). Choose based on your application.

Does this unit include earth leakage protection?

No. It includes an MCB + SPD. If RCD protection is required, pair with an upstream RCBO or specify an RCBO version.

How quickly is this supplied?

As it’s built to order, allow 3 working days for assembly. Once dispatched, next-day delivery applies.

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