Pat Testing Process

Visual display units; Computers; Kettles; Hand Drills; Photocopiers; Fridges; Mobile Phone Chargers; Vacuum Cleaners; Televisions; Video Recorders; Musical Instrument Amplifiers and PA systems; Heaters; and even PAT Testers!

Formal visual checks.

The Code requires that in addition to user checks, formally documented visual checks are routinely carried out.

Earth Bond Test.

Class I equipment normally conducted from 6A to 25A. This test is for checking the integrity of the resistance of the safety earth connection

Earth Screen Test.

Used to test I T equipment (e.g. computers, copiers etc) which require a low earth screen current of 100mA (Sometimes called business equipment or I.T. test). This is to prevent damage to the equipment.

Insulation Test.

For class I and II appliances, this is normally conducted at 500VDC, with option of applying a 250V test where mains input filters might give misleading readings.

Earth Leakage Test.

For class I and II appliances, used where insulation testing is not recommended. The current flowing into the appliance via the supply cable, is compared to that flowing out. Any difference must be leaking to earth, either via the earth lead (class 1) or the case or other connection (class 2).