If you use any electrical equipment outdoors, you are always encouraged to use an ‘RCD’. It’s likely that you will have used these in the school workshop as well. Lurking in the power supply circuit there will be MCBs as well….
The initials stand for ‘residual current device’, and these devices are sometimes called ‘earth leakage circuit-breakers’ (Figure 1). They are plugged into the supply socket and the equipment you are using is plugged into the front of the device. It is the job of the RCD to cut off the electricity supply if some defect arises in the equipment and some current flows where it should not (for example through a person). This could happen because some of the insulation has broken down and the metal casing has become ‘live’ or because someone has poked their finger, screwdriver etc. into the works. Using RCDs saves lives — or prevents someone getting a nasty shock. I remember seeing a technician get an electric shock when water got into some electrical machinery and I’m very glad it wasn’t me!
Your organisation does not have access to this article.
Sign up today to give your students the edge they need to achieve their best grades with subject expertise
Subscribe
