Consumer Units RCDs RCBOs

Consumer Units, RCDs, RCBOs and Surge Protection Explained Simply

If your fuse board is old or your electrics keep tripping, the terms can get confusing quickly. Here is what the main consumer unit protection does.

Updated 8 May 2026

A consumer unit is the main point where your electrical circuits are protected and controlled. In older homes, it may still be called a fuse box.

Modern boards can include different types of protection. The right setup depends on the property, the condition of the circuits and what work is being done.

What an RCD does

An RCD is designed to disconnect power quickly if it detects an imbalance that could indicate current flowing somewhere it should not, such as through a person or to earth.

RCD protection is especially important for sockets and outdoor use, but the exact arrangement depends on the installation.

Why RCBOs are often preferred

An RCBO combines overcurrent protection and residual current protection for an individual circuit. In practical terms, a fault on one circuit is less likely to take out half the property.

That can make fault finding easier and reduce nuisance when a single appliance or circuit has a problem.

Where surge protection fits

Surge protection is intended to help protect electrical and electronic equipment from voltage spikes. It is not a cure-all, but it can be a sensible addition in many modern installations.

When upgrading a consumer unit, it is worth discussing surge protection, labelling, future circuits and whether any existing faults need fixing first.

Signs your board needs looking at

  • Rewireable fuses or very old protective devices.
  • No clear circuit labels.
  • Repeated tripping or one fault turning off many circuits.
  • Damage, heat marks or buzzing near the board.
  • New kitchen, extension or outdoor power work being planned.

Relevant Electrical Work

If this article matches what you are dealing with, these are the service pages most likely to help.

FAQs

No. It improves protection, but existing circuit faults still need testing and repair.

Yes. Existing circuits should be checked before and after a consumer unit upgrade.

Yes. Relevant testing and certification is provided for completed consumer unit work.

Ask About This

Tell us what you are dealing with and where the property is. Photos of the consumer unit, fitting or fault are always useful.

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