2) INSULATION RESISTANCE TEST - Unless the equipment manufacturer/supplier specifies otherwise, insulation resistance testing (at 500V dc) will take place with the appliance mains switch in the "OFF" position. This is due to the fact that the majority of IT. Equipment power supplies utilize filters and protective devices. These are generally rated at 240 Volts, or just above, and tend to be connected across Live and Neutral and earth. Thus a standard PAT insulation test would greatly over stress these components and would in fact reduce the longevity and safety of the appliance. It may, in some cases, be possible to remove these "sensitive" components prior to testing, but generally speaking this is considered impracticable.

3) LOAD TEST - A load test should be carried out to protect the test engineer from possible hazards produced by a very low impedance being present between Live and Neutral during the OPERATION TEST. The test should be performed with the equipment turned "ON", and failure will halt further testing.

4) OPERATION TEST - An operation test should be performed to ensure that the equipment under test does NOT draw excessive current (the results obtained will not differ significantly from the manufacturer specification). Abnormally low currents will indicate open circuits or ruptured fuses which will need to be reported/repaired.

5) EARTH LEAKAGE TEST - This test should take place to measure the total current from Live and/or Neutral to earth under operating conditions. A result of not greater than 3.5 mA will be recorded.

NB: Certain noise suppression components may give rise to a failure result. The equipment manufacturer/supplier should be consulted where there is any doubt.

Failures:

For any equipment failing Electrical Safety tests, a procedure should have be previously discussed with the test engineer as to the action required of making safe any equipment. Should it be decided to remove any equipment from service, the flexible cord will be turned around the plug and secured with a nylon cable tie in such a manner so that the plug top cannot be inserted into a socket outlet. A "FAILED - DO NOT USE" label should be affixed in a prominent position on the equipment and the Premises Manager and Network Services Department notified immediately. A "FAIL" status will be entered against the item on the Equipment Register. A list of all FAILED items should be presented to the facilities manager.

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