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This is a basic "survival guide" to PT testing.

Summary

Portable Appliance Testing (PAT) is an essential procedure both before and after attempting to repair any mains operated electrical equipment, ensuring basic safety.

A PAT test comprises two parts: firstly a visual inspection (which in fact reveals the majority of faults), and an automated test using a PAT tester.

It's important to understand that the automated test still requires that you correctly identify the class of equipment, since if you get it wrong you could pass a faulty appliance as ok with potentially dangerous consequences.

Visual Inspection

A visual inspection generally turns up more faults than an electrical test, and shows faults that an electrical test may not. It should therefore should never be skipped.

You should perform the following checks:

• Check for fraying of the mains lead, or cracking of the insulation. In the event of any cracking of the inner insulation exposing the copper conductors, the owner should be advised that the appliance is positively dangerous, and must not be used until the mains lead has been replaced.

• Check for a cracked or broken plug. This will need to be replaced before the appliance can be declared safe.

• Check that the cable clamp on the plug (and on the appliance itself, if there is one) is firmly gripping the cable and allowing no movement. Often, this can be rectified by refitting the plug.

• Particularly on an older appliance, open the plug and check that it's correctly wired, the screw terminals are tight, and that a suitable fuse is fitted. Even if you don't open the plug, check the screws are tight. (In the case of a moulded-on plug there will be no screws and you won't be able to open it.)

(Pics to be added.)

Safety

As previously stated, it is essential to correctly identify the class of an appliance otherwise a faulty appliance could be passed as OK with potentially dangerous consequences.

All mains powered appliances should be PAT tested both before and after a repair is attempted.

A faulty appliance must have its mains plug removed and the owner must be informed that it is unsafe unless the fault can be immediately rectified (e.g. by replacing a cracked mains plug).

External links

• External links as bullet points