The Consumer Unit board also known as a fuse box is the most important and fundamental electrical safety requirement for any building. Whether it is an apartment, house or office, there must be a consumer unit installed to ensure electrical safety regulations. The purpose of the consumer unit board is to distribute electricity safely from the mains supply to individual circuits around the home or workplace. The consumer unit boards divide the electrical power feed into secondary circuits to provide safe electricity and comprehensive circuit protection solutions.  

Every year, people are injured from electrical accidents at home or work which can be easily prevented. According to the Electrical Safety Foundation International (ESFI), there were 166 fatal electrical injuries and 1,900 non fatal electrical injuries in 2019. The consumer unit board has two vital functions which are protection of cables from overload and the protection of humans from electric shock. Installing a Residual Current Device (RCDs) or Residual Current Circuit Breaker (RCBOs) protection in your consumer unit can prevent injuries and deaths from occurring.  

The consumer unit is made up from various elements including the mains switch, residual current devices (RCDs) and miniature circuit breakers (MCBs). It is vital that the owner of the property is aware of where their consumer unit is located in an event of an emergency or during electrical repairments to turn the consumer unit on or off.  

What makes up a Consumer Unit:  

Main Switch:  

The main switch is the main circuit breaker for the overall electricity within a property. The switch allows the end user to control the electricity in their home by turning the power to their home on and off. If the main switch is turned off, the consumer unit will become insolated and the property will not be provided with a supply of electricity. The main switch is commonly used to carry out repairs on the electrical system safely.  

Residual Current Device (RCDs): 

The Residual Current Devices (RCDs) are one of the most important safety devices within the consumer unit boards. RCDs are an essential and mandatory requirement within households and commercial environments for safety purposes. The RCDs is used to prevent injury and death caused by electric shock and fires. The device is designed to detect an imbalance power flow within the electrical circuit. 

RCDs are a potential lifesaving device designed to prevent fatal electrical shock.  During an event, where the end user touches live wiring, the RCD will detect untended paths and will trip reducing the risk of a life-threatening injury.  

RCDs are also designed to provide protection against potential earth leakages caused by fires. Earth leakages can be caused by poor installation or DIY tasks. If the earth leakage is detected, the RCD will trip and turn the circuit off to prevent potential hazards in the future. 

Lives 2 Pole RCDs are suitable for all consumer units and enclosures in the LVE range: 

• CE certified and meets the requirements of EN61008. 
• Provides protection against earth fault/leakage current. 
• Automatically disconnect the circuit when earth fault/leakage current occurs. 

Miniature Circuit Breaker (MCBs):  

In every property there are many circuits, on average there is six circuits in a home which is controlled by a circuit breaker. Miniature circuit breakers (MCBs) are designed to identify overcurrent faults. The overcurrent faults can be caused due to overload of power, commonly caused when there are too many appliances plugged into the one circuit.  Similarity to the RCDs, MCBs will automatically turn off when there is an overcurrent fault in the circuit to protect the end user against risk of electric shock. An example of overcurrent would be, if an end user had a 10 amps circuit breaker but the circuit breaker identifies 12 amps, the circuit will automatically trip for safety purposes.  

There 3 different types of MCBS which are: type B, type C and type D.  

Type B MCBs are used in domestic circuit protection where there is little need for surge protection. They are designed to trip the current flow if it hits between three and five times the recommended rated load. Type C MCBs are used in commercial and industrial environments that require more powerful electrical devices. Surges are likely to be higher and are required in these environments. Finally, type D MCBs are designed for heavy duty commercial and industrial environments where strong current surges occur, for example, welding equipment, x-ray machines and other heavy industrial facilities.  

Live’s 1 Pole MCBs are designed for use with all consumer units.  

• CE certified and meets the EN60898 requirements. 
• Provides protection when overcurrent is detected 
• Automatically disconnects the circuit when overcurrent is detected. 

Residential Current Operated Circuit Breaker (RCBOs): 

Not all consumer unit contains a residential current operated circuit breaker. An RCBO has the functionality of both an RCB and an MCB. The device is able to provide protection against overloads, short circuits and earth leakage currents. Read more about RCBOs in our previous blog. 

Surge Protection Device:  

Surge protection devices are used to provide protection against power surges. Surge protection are designed to limit the amount of voltage supplied to an electric device. All appliances within homes and commercial industries are vulnerable to power surges which can cause damage to the circuit and the electronics. The most common cause of power surges is faulty appliances and faulty wiring which surge protection devices can prevent these issues. The device acts as a layer of protection for the electrical system. Surge protection is not mandatory but it is strongly recommended for installations in accordance with 18th edition wiring regulations. Without surge protection, a power surge will occur and shorten the life expectancy of the appliance. 

Garo's Surge Protection Kit 2 Pole can easily be added using the GARO G_GPT2 Kit: 

Dangers to look out for in Consumer Units:  

Thermal Damage:  

If the consumer unit has any signs of thermal damage. It is advised to replace the consumer unit to prevent potential hazards arising. If the consumer unit has a burning smell or is making a crackling sound, the end user must call a registered electrician immediately for expectation.  

Regular Power Cuts:  

If the property is experiencing regular power cuts, it is important to contact a registered electrician to inspect the circuit and identify the issue for power cuts. The consumer unit is designed to trip when danger is detected. The main reason is to prevent any potential dangers including electrical shocks or fatal injuries.  

Regular Maintenance:  

It is important to take care of the consumer unit. Consumer units are the most important element within the home or business therefore, regular maintenance is essential to ensure the consumer unit is in good condition and to prevent problems in the future. It is vital to carry out regular checks on the consumer unit. RCDs must be tested every 6 months to ensure the device is working correctly to protect the end user and the property. It is also important to have a periodic inspection carried out every 10 years to ensure the electrical wiring is safe and complies with the regulations.  

Consumer units are extremely important for the safety of you and your home or business therefore, it is important to carry out check ups. The regular inspections ensure the consumer unit and the devices within the board is working properly and that the end user and the property will be safe.  

At Meteor Electrical, we have a range of distribution boards including 18th edition metal boards, empty boards, IP rated boards, Irish consumer units, priority and non priority boards! For more information on purchasing one of our consumer unit boards, RCDs, MCBs, RCBOS and Surge Protections send an email at [email protected] or speak to one of our friendly advisors on the live chat!  

We go into more detail about the different types of consumer units in this blog.