We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Distribution Board?

By Paul Scott
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A distribution board is a panel or enclosure that houses the fuses, circuit breakers, and ground leakage protection units used to distribute electrical power to numerous individual circuits or consumer points. The board typically has a single incoming power source and includes a main circuit breaker and a residual current or earth leakage protection device. Older distribution boards may include a series of fuses which supply the individual circuits; newer installations typically feature mini circuit breakers. A distribution board may be used to distribute either single or three phase supplies depending on the installation specifics. Although distribution board equipment, layouts, and legislative requirements differ from country to country, the basic principles of “distributing” a single supply to various individual points while ensuring safety and control for each remains the same.

Distribution boards are common place in most industrial installations and commercial or residential buildings. Most consist of a panel or enclosure supplied with a single incoming electrical feed cable. The power is then split among several small circuit breakers or, in the case of older boards, fuses which in turn feed power to different consumption points or circuits. The core function of any distribution board is to allow individual circuits to draw power from correctly rated circuit breakers and for those circuits to be isolated without causing a disruption to the rest of the supply. Most importantly though, the distribution board offers protection to users and equipment from electrical shock or fire resulting from ground faults.

Most distribution boards feature a single incoming supply cable feeding multi- or single-phase power to the board. The live feed from this cable is generally first connected to a main breaker, fuse, or residual current detector (RCD). These components allow the whole board to be isolated for repairs in the case of a main breaker or fuse while the RCD protects against ground fault shock and fire hazards. In the case of a single phase supply, the live feed is taken from the main breaker or RCD and bridged across the top of a series of individual fuses or mini circuit breakers. Multiphase supplies typically have several circuit breakers for each phase and with each group bridged along their incoming terminals. The neutral and earth cores of the supply cable are then connected to separate busway bars.

Cables from the individual power outlets, light circuits, or machine points are then inserted into the distribution board on the opposite side of the supply cable. The live leads from each cable are connected to suitably rated circuit breakers and the neutral and ground leads to the appropriate busway bars. This creates a distribution environment where each circuit is fed by a suitable circuit breaker and may be isolated if the need arises without disrupting the rest of the supply.

The most important part of any distribution board is, however, the RCD. This is the component which stands between the circuit user and potentially fatal electric shocks and catastrophic fires. For this reason, these units should be correctly rated, regularly tested, and never bypassed. The cause of a tripped breaker or blown fuse should also always be investigated prior to a reset to avoid possible damage to equipment or appliances and electrical shock.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.