My extension lead has failed the PAT Test! How can I be sure that I am supposed to fail it?
You need to be sure that the appliance should be failed, before condemning the appliance. So read on to find out if the appliance really is faulty or if the process hasn’t worked, or if there is an exception.
If the extension lead fails the earth continuity (Rpe) Test one of two screens will appear.
This screen on the left indicates the lead has failed the earth continuity (RPE) test because the earth wire is broken or the electrical resistance of the earth wire is too great to be considered safe. The lead must be removed from use, and clearly marked as failed pending repair or disposal.
This screen below (and above right), which shows figures after a failed earth Rpe test, indicates that the appliance has a longer lead than normal.
A calculation of its length and cross-sectional area (CSA) will determine whether the electrical resistance of the earth wire falls within acceptable limits, as prescribed in Table A on page 15 of the operating instructions.
The CSA will be marked on the lead. See below the one on the left has a CSA of 0.75mm2 and on the right 1.25mm2
The calculation is 0.1 ohms plus the sum of the length of the lead multiplied by its corresponding ohms value.
Repeat the test for any remaining sockets on the extension lead from left to right.
If the screen reading falls within acceptable limits, place a “Pass” label on the lead and complete the relevant Portable Appliance Test Report sheet noting the screen readings, length and cross sectional area of the lead.
If the calculated figure is greater than the maximum resistance allowed, the extension lead must be removed from use, and clearly marked as failed pending repair or disposal.
If the extension lead fails the Insulation (Riso) test and it is NOT surge protected, it is unsafe and must be removed from use and clearly labelled as failed pending repair or disposal.
If the extension lead fails the Insulation (Riso) test, and it IS surge protected it should be re tested using a class I appliance. This will confirm whether the appliance failed Riso due to faulty insulation, or because of the surge protection devise. It should PASS the earth continuity (Rpe) test, FAIL the Insulation (Riso) test but PASS the Leakage .
Extension Lead failed a PAT Test? Not sure what to do? Call us on 01392 364933 or email sales@parker-bell.co.uk for free technical support and advice.