Why is it Called 'PAT Testing?'

That's a really good question!

Perhaps you've heard someone say LCD Display. But you probably know that LCD stands for Liquid Crystal Display, so when they say LCD Display they are saying the word display twice. It's the same with PIN Number. Next time you hear someone refer to their PIN Number, try asking them what it stands for!

Of course we know that the phrase PAT Testing is wrong, what we are actually saying is Portable Appliance Testing Testing!

But the phrase is so common in our industry that we are happy to continue using it, even though it goes against the grain a little, cause we strive for accuracy and excellence in all that we do.

You might be interested to know that the phrase PAT Testing is an example of Redundant Acronym Syndrome. To be ironic, we shorten this to RAS Syndrome. But then if we had lives we'd probably do something else for a living......

What Appliances Do I Need to Have Tested?

All electrical appliances connected to a source of electrical energy through a plug top. This includes 240v, 110v and three phase appliances. Examples are Extension leads, IEC leads, all IT equipment including chargers, kitchen appliances etc. Basically, anything that you plug into a power socket needs to be tested.

Why Do I Need to Have My Appliances Tested?

Portable Appliance testing (PAT) is an important aspect of any companies health and safety policy. Twenty five percent of all reportable electrical accidents are due to everyday faulty portable appliances. PAT testing is a series of tests on an appliance to determine the safety of that appliance.

Some insurance companies require regular PAT testing. The most important thing is to minimise any risk to you or your employees.

What tests are conducted on an appliance and what do they mean?

  • Full visual inspection - The test engineer checks the flex of the appliance for any signs of melting, cuts or frying. They will then check the plug top and check that the plug is terminated correctly and that it has the correct fuse. Finally the casing of the appliance will be checked to make sure that all covers and cases are present and that the power switches operate correctly.
  • Earth Bond test - This test is performed using a PAT tester such as Kewtech KT71. The earth bond test is very important as the safety of a class 1 appliance depends on it having a good earth connection. This test is not performed on class 2 appliances as they do not rely on an earth connection to function safely.
  • Insulation test - This test is used to ensure that there is adequate insulation between the mains supply pins of the plug.
  • Earth Leakage test - This test measures the current from live parts to earth on class 1 appliances or from live parts to accessible surfaces for class 2 appliances.
  • Load and function test - This is a useful way of ensuring that the appliance is operating correctly and that no previously undetected faults are present.
  • Polarity tests - Ensures that the correct polarity exists on extension leads and IEC leads.

 What's the difference between class 1 and class 2 appliances?

Class 1 appliances are ones that require an earth connection to function safely. Class 2 appliances are not earthed, instead they are double insulated.

 What is calibration and do I need to do it?

Calibration is the process used to ensure a measuring instrument is working in its designated accuracy. PAT testers should be calibrated after every 12 months of use - for more information on Calibration click on this link PAT Tester Calibration