Experts in PAT Testers & Equipment
Order & Advice Line 01642 987976

How To PAT Test Computers

Particularly if you're PAT testing in offices, you're more than likely going to encounter computers as part of your portable appliance testing regime.

A computer is an electrical appliance and must be PAT tested. There are, however, several rules to follow when PAT testing a computer as normal testing procedures could result in damage being caused to your IT equipment.

To perform testing on computers, follow these points.

1 - Test The Power Cord

The computer's power cord must be tested independently from the actual computer to ensure safety.

When testing the cord, perform the following:

  • Visual Inspection - examine the cable yourself, looking for problems such as breaks in the wiring, exposed internals or a broken flex on the plug

After confirming that the cable is suitable for use and doesn't have any obvious problems, use your PAT tester to perform the following tests.

  • Earth Continuity
  • Insulation test at 500V DC
  • Polarity

Once the lead is confirmed to pass each of these tests, you can use it when testing the actual computer.

2 - Test the Computer

Note: Testing the actual computer requires a PAT tester that has the ability to perform an earth continuity test with a test current of no more than 200mA. If you use a higher current, there is a serious danger that the motherboard of the computer could be damaged.

Like the power cord before it, the computer must also be subjected to a visual inspection. Check the tower and associated equipment for obvious problems, and if there's any doubt about safety, fail it immediately and recommend repairs to the correct person.

If the computer passes the visual test, use the power cord you tested earlier to plug the computer directly into your PAT tester. You should then use the earth bond lead to touch the bare metal (usually on the back of the computer) before performing the following test procedures:

  • Earth continuity test at 100 or 200mA - Remember not to use a current more than 200mA as this can damage your computer internally!
  • Insulation test at 500V DC or (for older computers) a leakage test to ensure safety

If you follow these rules, you should be able to test IT equipment with ease!

1.9