Testing extension leads is actually very easy. You will require an adaptor in the form of a short IEC lead (IEC plug one end and a 13A plug on the other). After completing the visual test you plug the 13A plug into the 13A socket on the tester; you then plug the IEC plug of the short IEC lead into the IEC socket on the tester. Following this you plug the 13A plug on the short IEC lead into the end 13A socket (The one furthest away from the mains lead end). This is to ensure that you are testing the full length of the Buss Bars which connect all of the pins in the sockets together. You now proceed with the lead test which comprises Earth Continuity, Insulation at 500 Volts DC and Polarity which checks that Line and Neutral are not reversed. Some people wrongly think that it doesn’t matter, but in fact it is very important to get them the correct way around. If they are reversed, both the switch and fuse are in the neutral leg, which means that the appliance is live even when switched off and if a fault occurs, the fuse will not blow probably resulting in a fire.
Although it is not a written requirement I like to use a socket tester to prove the remaining sockets. You simply unplug the extension lead after the PAT test and plug it into a mains supply. Plug the tester into the remaining sockets on the extension lead, thus ensuring that all sockets have been tested.
