With computers you test the power cord fist with a standard lead test comprising:

1. Visual.
2. Earth Continuity.
3. Insulation at 500 Volts DC.
4. Polarity.

You then test the computer with its own lead using the following tests:

1. Visual.
2. Earth Continuity at 100 or 200 mA (Depending upon the manufacturer). You must not test the computer with a test current higher than 200mA; you may well damage the motherboard. This means that testers which do not have a 100 or 200mA test current must NEVER be used on IT.
3. Insulation Test at 500 Volts DC (If the computer is old you may wish to use the leakage test in place of the standard insulation Test.

For the test you plug the computer into the 13A socket on the PAT tester using its own power cord and connect the earth bond lead to bare metal (usually at the back).

Written By Austin