Prometheus Electrical - Changing a Consumer Unit: A Comprehensive Guide

Feb 14, 2024


Welcome to Prometheus Electrical, your trusted source for lighting fixtures & equipment and professional electricians. In this comprehensive guide, we will walk you through the process of changing a consumer unit, providing you with step-by-step instructions, safety protocols, and valuable tips to ensure a seamless installation process.

Why Change a Consumer Unit?

Consumer units, also known as fuse boxes or distribution boards, play a crucial role in electrical systems. They control and distribute electricity through circuit breakers, protecting your electrical appliances and wiring from potential damages caused by electrical faults. Changing a consumer unit is necessary for various reasons, including:

  • Upgrading to meet modern safety standards
  • Increasing the number of circuits to accommodate additional electrical loads
  • Replacing an outdated or faulty unit

The Process of Changing a Consumer Unit

Step 1: Safety First

Prioritize safety by following our recommended safety protocols:

  1. Turn off the main power supply to avoid any potential hazards.
  2. Wear appropriate safety gear, including insulated gloves and goggles, to protect yourself against electric shocks.
  3. Ensure a fire extinguisher is easily accessible in case of emergencies.
  4. Work in a well-ventilated area to prevent the build-up of harmful fumes.

Step 2: Understand Your Electrical System

Before proceeding, it's essential to familiarize yourself with the components of your electrical system. This includes understanding the functions of the main switch, circuit breakers, and RCD (residual current device).

Step 3: Create a Wiring Plan

To ensure a smooth installation process, create a detailed wiring plan. This plan should outline the placement of circuits and their corresponding breakers, ensuring a logical and organized layout.

Step 4: Gather the Required Tools and Materials

To complete the process efficiently, gather the necessary tools and materials, including:

  • New consumer unit
  • Screwdrivers (including insulated ones)
  • Wire strippers
  • Electrical tape
  • Labeling materials
  • PVC insulation tape

Step 5: Shut Off Individual Circuit Breakers

Before removing the old consumer unit, shut off the individual circuit breakers. This ensures that specific circuits are not active during the installation process, minimizing the risk of electrical shocks.

Step 6: Disconnect Old Consumer Unit

Carefully disconnect the old consumer unit by loosening the screws connecting the cables. Take note of the wiring connections to ensure a proper reconnection in the new unit.

Step 7: Install the New Consumer Unit

Follow these steps to install the new consumer unit:

  1. Mount the new unit securely on a suitable surface using the provided fixings.
  2. Connect the incoming supply cable to the main switch of the new unit. Ensure the connection is tight and secure.
  3. Connect the individual circuits to their corresponding breakers based on your wiring plan.
  4. Double-check all connections to ensure they are properly tightened. Any loose connections can lead to electrical faults or even fires.

Step 8: Test and Certification

Once the new consumer unit is installed, it's crucial to test its functionality. Power up the main supply and check each circuit to ensure everything is working correctly. Additionally, consider seeking professional certification to validate the quality and safety of the installation.

Contact Prometheus Electrical for Professional Assistance

At Prometheus Electrical, we understand the importance of a seamless consumer unit change. Our team of expert electricians possesses the knowledge and experience to handle any electrical project, ensuring safety and efficiency. Contact us today for reliable lighting fixtures & equipment and professional electricians who prioritize excellence.


Changing a consumer unit is a task that should be approached with caution, and we highly recommend seeking professional assistance if you are unsure about any aspect of the process. However, with the detailed instructions and safety protocols we have provided, you have the information you need to successfully change a consumer unit.