When it comes to electrical components, there are few more useful and common than the consumer unit. This electrical component is easy to identify and can be found in many locations, such as the garage or utility room. This article will explain what this component is, how it works, and why you should always check its condition. Read on to learn more about this useful electrical component! And remember, this article does not cover MCBs, Residual Current Devices, or Metal clad consumer units.

Residual Current Devices

A Residual Current Device, or RCD, is a type of protection device that monitors the wiring installation. It continuously measures the current that passes through the wires and breaks the circuit when the difference reaches 300 mA. This device can help prevent fatal electrocution if the wiring installation has a leak. Its dual function lets it protect the home from both electric shock and fire.


One way to describe Consumer Units is by comparing them to electrical sockets. The main difference between these two types of sockets is their function. The MCB (Multi-Current Breaker) has a live feed from the main switch while the RCD (Residential Current Device) has a dead feed from the main switch. This is what separates an ordinary Consumer Unit from a dual-phase one.

Residual Current Overload

Residual Current Devices, also known as RCDs, protect consumers from the risk of an electric shock and fire by detecting an imbalance in the flow of electrical current. In cases where a grounded person touches live wiring, the RCD will trip the circuit and disconnect power. While this device is necessary to prevent the risk of electric shock, it does not provide protection against overload and short-circuit conditions.

Metal clad consumer units

If you’re considering upgrading your old re-wireable fuse box consumer unit, consider changing to a Metal Clad unit. These units use circuit breakers instead of re-wireable fuses and incorporate RCD Testing. While plastic units are not as safe as metal ones, they do offer better protection from electrical shock and fire. If you’re not sure if you should switch to metal, learn more about these units to make the right choice for your home.

Surge protection

Consumer units for surge protection are designed to protect entire homes from voltage spikes. They also protect expensive electrical devices and appliances, prolonging their life spans and reducing replacement costs. The main switch consumer unit is supplied empty, but populated with a variety of protection devices, including an RCD and an MCB. Other types of consumer units include RCBOs and surge protectors. However, they are not suitable for all types of circuits, including the main switch.