Electrical installations need to be regularly checked to ensure they remain safe, according to the Health & Safety Executive (HSE). This is especially important in areas where electrical sockets or wiring are likely to become damaged.
“Socket testers are designed to identify a variety of faults with socket wiring, but many commonly used socket testers cannot reveal a poor earth that could lead to someone being killed,” warns the HSE.
“A socket might have a poor earth for years with no visible signs. However, when an appliance plugged into it develops a fault, earthed metalwork can become permanently live at a dangerous voltage. This could give the user a fatal electric shock, or cause a fire.” (www.hse.gov.uk/electricity/socket1.htm)
Steve Dunning, managing director of Martindale Electric, recommends that users of simple socket testers consult the above HSE website. He says: “Martindale has introduced the E-Ze 150, a socket tester that gives an accurate indication of earth loop impedance in bands. Now, users can buy a small plug-top shaped socket tester testing the quality of the earth for less than £50.”
There are three types of socket tester: simple, advanced and professional. Simple socket testers can detect various faults but cannot identify some extremely dangerous poor earth faults. Advanced and professional socket testers can measure the earth fault loop impedance on indicator lights or a digital display.