Earthing can have a few different meanings depending upon its application, however its purpose is always the same – to keep electrical equipment as safe as possible. When all metallic parts in electrical equipments are grounded, if that equipment were to fail there would be no dangerous voltages present in the equipment case. This makes the removal, maintenance and servicing of electrical equipment as safe as possible.
All electrical equipment is ‘earthed' by the outer housing of equipment being directly connected to an earth grid or electrode. This provides a low resistance path to the ground.
Electrical bonding is defined as the practice of intentionally connecting all metallic non-current carrying items in a room to protect from electric shock. Electrical earthing and electrical bonding is a two step process to ensuring electrical equipment is safe. Electrical bonding differs from electrical earthing due to earthing aiming to prevent a dangerous situation in the first place and bonding providing a protective conductor to stop any electrical current passing through metallic items not directly connected to a machine. In its most basic form, bonding is in place to minimize the risk of touch voltages.
Both electrical earthing and electrical bonding are essential ingredients to safe electrical equipment within a home or place of work.