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What Is a 4-Way Consumer Unit Used For? (Installer’s Guide)

A 4-way consumer unit is one of the most common compact boards used across EV, heat pump, garage, and outbuilding installs. Electricians typically choose them when they need a dedicated enclosure with space for an RCBO, surge protection, and a clean, compliant layout for a single circuit.

Quick Answer: A 4-way consumer unit is used when you only need a small number of protected outgoing ways - typically for EV chargers, heat pumps, garage circuits, or small upgrades where a full-size board is unnecessary. Most installers pair them with Type A RCBOs and Type 2 Surge Protection to stay compliant under the 18th Edition.

This guide explains where 4-way boards are used, how they’re configured on-site, and which models work best for EV and renewable installs.

These compact boards form part of our wider Consumer Units range, which includes everything from small EV-ready enclosures to larger multi-way boards for full domestic rewires.

What Is a 4-Way Consumer Unit?

A 4-way consumer unit provides space for up to four outgoing circuits. In most installations, only one or two ways are used - but the extra capacity allows room for surge protection, communications modules, or a future second circuit.

Your full range of EV-ready 4-way units can be found here: 4-Way Consumer Units.

They’re commonly fitted with:

  • Type A RCBOs for compliant earth leakage protection
  • Type 2 Surge Protection (strongly recommended for EV and renewables)
  • B or C curve depending on load and inrush current

Where Is a 4-Way Consumer Unit Used?

Installers use 4-way boards when they need a compact, dedicated enclosure for a single protected circuit or small group of circuits.

Typical scenarios include:

  • EV charger supplies (32A or 40A, B or C curve)
  • Heat pumps and inverter-driven systems
  • Garage and outbuilding distribution
  • Garden offices and annexes
  • External lighting or power circuits
  • Retrofits where the main CU is full

Regulation Reminder: For EV chargers, heat pumps and most inverter-driven equipment, Type A RCD/RCBO protection is required under 18th Edition Amendment 2. This is why most installers opt for A-Type 4-way boards with built-in surge protection.

4-Way Consumer Units for EV Chargers

4-way boards are the standard choice for EV charger installations because they offer enough space for:

  • A-Type 32A or 40A RCBO (B or C curve)
  • Type 2 SPD (recommended or required for EV installs)
  • Future accessories or comms modules

Popular EV-ready 4-way units:

Using a 4-Way Consumer Unit for Heat Pumps & Renewables

Heat pumps and inverter-driven systems benefit from having a dedicated board with their own Type A RCBO and Type 2 SPD. A 4-way enclosure keeps the circuit clean, compliant and separate from the main domestic CU.

  • Room for an inverter-friendly RCBO
  • Space for Type 2 surge protection
  • Metal enclosure suitable for garages and utility rooms
  • Future room for monitoring modules

How to Choose the Right 4-Way Board

Choosing the right 4-way board comes down to matching the circuit’s load, inrush behaviour and compliance needs. Here’s the quick way to spec it correctly without overthinking it.

1. Choose your curve type

B Curve: Standard domestic loads.

C Curve: Higher inrush - common on EV chargers and inverter-driven heat pumps.

2. Choose your rating (32A vs 40A)

32A suits most 7kW EV chargers; 40A gives more headroom for heat pumps or larger circuits.

3. Surge protection is strongly recommended

Most EV and renewable installations require Type 2 SPD under the 18th Edition. All four units in the range include it as standard.

4. Use a metal enclosure

Metal is standard in modern compliant installs and offers better durability and fire containment.

Explore all 4-way units: 4-Way Consumer Units

FAQs

Installers often ask the same practical questions when deciding if a 4-way consumer unit is suitable for their job. Here are the most common ones.

Can a 4-way board run more than one circuit?

Yes - you have up to four outgoing ways. Many EV or heat pump installs only use one or two, leaving room for future additions.

Do I need Type A RCBOs?

Yes. EV chargers, heat pumps and inverter-driven systems require Type A protection under the 18th Edition.

Is a 4-way unit big enough for a garage supply?

Yes, provided the load is appropriate and the circuit is designed correctly. Many garage and outbuilding installs use 4-way units.

Do all 4-way boards need surge protection?

For EV chargers and renewable systems, Type 2 SPD is strongly recommended and often required by the regulations.

👉 Ready to spec an EV-ready or heat-pump-ready board? Browse all 4-Way Consumer Units