How to Test and Tag a Computer

When learning how to Test and Tag a computer, you'll be shown that there are essentially four items that need to be tested: the monitor, desktop PC and 2x IEC leads.

Each one of these items will also require its own test tag (there is a common misconception that computers only require 1 tag). Also, ensure the PC is shut down correctly before testing.

PC's are connected to the monitor via a VGA cable. As these cables are designed to shield themselves from electromagnetic interference, this shielding connects the earth of the desktop to earth of the monitor. Knowing this information, testing and tagging computers can be made easier as the 'earth return' lead does not have to be moved when testing the system.

Mains points to remember:

  • Computers need four items tested
  • Each of these items also require tags - four tags in total
  • The monitor and desktop PC can be tested with an Insulation Resistance test (as per video or Leakage Current Test)
  • All desktop PC's and most monitors are Class I Earthed Appliances
  • The desktop and PC monitor can be tested together as a Class I Earth Appliance