Bonding is a less 'glamorous' aspect of the work an electrician carries out in your home, with no visual grand finale like there would be when a new light is fitted and switched on.
It is a highly essential safety element in your home, ensuring metal services coming out of the ground - such as metal gas and water pipe etc - do not provide a better route for electricity to flow in the event of a fault than the earth of the electrical installation.
A qualified Part P electrician will always ensure earthing and bonding work is carried out on your electrical installation, however this very important work is nearly always overlooked by an unqualified person.
What is Bonding?
Bonding should not be confused with earthing. You may have heard of the term 'earth bonding' this is effectively a meaningless term, as the earth and bonding are two separate connections.
Bonding is a connection of metallic parts within an electrical installation so that they all are equally “well earthed”. The reason for this is although your property may have a sufficient earth connection at the meter, a service pipe (such as gas or water) may provide a better earth and therefore in the event of a fault would be the route electricity takes as opposed to the earth of the faulty equipment. As an example a protective bonding conductor is simply a connection between the main earth of the property (at the electric meter) and the main water pipe.
Why do we bond to gas and water?
OK so now the importance of earthing and bonding is known, why does an electrician also bond to gas and water?
Without bonding to the gas and water installation pipes, the risk of this pipework 1) becoming live in the event of a fault or 2) introducing the risk of shock due to having a different potential to the main earth, is greatly increased. It also a very important electrical regulation and your electrical installation cannot be certified without it.
How to recognise if your home has correct bonding
To find out if your electrician has carried out earth and bonding correctly, take a look at your main gas meter. You should see a green and yellow 10mm cable attached to it. In addition, also take a look at your main water stopcock, you should see a similar connection. Earthing and bonding are both visually similar in terms of the green and yellow colour identification. Do remember though that in order for an electrical installation to be deemed safe, satisfactory bonding must be carried out within 600mm of the meter or stopcock or where the cables enter the property.
If you have any doubts about you installation. Call Luke at The Electric Company (Dorking) - Your Local Electrician on 01306 888915. We are based in and have been serving Dorking and the Surrounding area since 2013.