A registered electrician will check the earthing and bonding on any installation he works on. This is because the safety of any new work you have done (however small) will depend on the earthing and bonding arrangements.
Earthing is used to protect you from an electric shock. It does this by providing a path (a protective conductor) for a fault current to flow to earth. It also causes the protective device (either a circuit breaker or fuse) to switch off the electric current to the circuit with the fault.
A recent example we came across was an electric hob with a fault, a live cable inside the hob had come loose and was touching the metal casing. The casing was earthed so the fault current flowed to earth through the protective (earthing) conductors and caused the fuse/MCB’s to trip. If it wasn’t earthed, the metal casing would have stayed ‘live’ waiting for the next person to touch it to get a nasty shock!
Two important things to consider from the above:
- Is your homes electrical installation correctly earthed
- Do you have the correctly rated and functioning protective devices in place
Bonding is installed to negate the risk of electric shocks to anyone who may touch two different metal parts when there is a fault somewhere in the supply of electrical installation. By connecting bonding conductors between particular parts, it reduces the voltage there might have been.
The types of bonding generally used are main bonding and supplementary bonding.
Main bonding consists of Green and yellow conductors(wires) that connect metal service pipes (gas, water or oil) from inside a building to the main earthing terminal(MET) of the electrical installation.
Supplementary bonding – Green and yellow wires that connect accessible metal parts of electrical equipment (such as a heated towel rail) to accessible metal parts of electrical equipment and/or accessible metal parts of items that are not electrical (such as pipes). These connections are made to prevent a dangerous voltage between two accessible metal parts, in case there is a fault. You may need supplementary bonding for rooms containing a bath or shower, except where all circuits in the room are RCD protected and the main bonding is up to the required standard.
If you are concerned about your Earthing and Bonding and are based in Peterborough, Stamford, Market Deeping or surrounding areas. Please do get in touch by calling us on 01733 698151, or send us an email to firstname.lastname@example.org.