Power Distribution Unit Safety Hardware Explained – RCDs, MCBs and RCBOs

Our Power Distribution Units are a fantastic piece of equipment that can be an efficient and convenient method of distributing an electrical circuit from a single input source to multiple output devices in the branch circuit. That being said, their features can vary – including the safety hardware. Maybe you’re thinking about purchasing one of our power distros or maybe you would just like to learn about the different safety options that we can add? Either way, this guide will explain the 3 most common safety features we add to our power distribution units.

What is an RCD?

An RCD is a Residual Current Device, for those of us not as au fait with technological terms, let us explain. An RCD is designed to prevent you from the dangers of a live, bare wire. They’re extremely sensitive and are made so that if they notice there is a fault in the circuit the safety device switches off the electricity automatically. Perfectly for protecting people against the risks of electrocution and fire caused by earth faults.

Example:  A cable being run through a festival has a split along it and the bare wire is exposed. If someone were to step on it or the wire is outputting energy elsewhere, the RCD would notice that the electricity is running down an unintended path and it would switch off the power incredibly quickly as to minimise any risk of injury or fire.


What is an MCB?

An MCB is a Miniature Circuit Breaker, an electromechanical device that is designed solely to protect an electric circuit from over-current. Much like a fuse, when the current running through the circuit is too powerful, the electrical connection will blow and protect the rest of the circuit. Unlike a fuse however, MCB’s are reusable and don’t break when there is an overflow. Not only are they reusable, but they’re safer and much easier to use.

Example: 200 amps are being pulled through a circuit that is designed to only manage 125 amps. There is too much power for the circuit and this can cause damage. The MCB notices that there is an over-current and switches off the electricity before any permanent damage can be caused to the circuit.


What is an RCBO?

An RCBO is a Residual Current Circuit Breaker with Over Current Protection. As an RCD protects the people and environment and a MCB protects the equipment, an RCBO can protect all three. RCBO’s can only be used on certain power distribution units however, so it is always best to get in contact with us on 01752 817140 to check.