What's the point of 110V?

110V appliances are often used on construction sites. 110V transformers are used to produce 110V from the UK mains voltage of 230V. What's the benefit of using 110V?

Nightmare plugs found in student accomodation

All of these plugs have been found in various student accomodation where PAT testing has been carried out. This highlights the importance of a good formal visual inspection which includes looking inside a plug.

Do you think they used a pair of scissors to strip the insulation on this one?

5 faults that a PAT tester will NOT find

Some users of PAT testers assume that ALL faults on an appliance can be found by plugging it into a PAT tester and carrying out the tests. This assumption can lead to a lot of faults with appliances NOT being found. Below are some of the common faults that can be missed.

Why does the Insulation Resistance test PASS with nothing plugged into the PAT tester?

This is a question we often get asked during the PAT testing courses. On any PAT tester, just press the Class II button. The tester will carry out the Insulation Resistance test and display a PASS - even with nothing plugged into the tester.

Why does this happen? Is the tester faulty? The answer is NO.

City & Guilds 2377 qualification

Overview

There are no qualifications required prior to undertaking PAT testing. There are many training courses designed to bring delegates up to the required standard of competence for carrying this out.

The City & Guilds 2377 qualification is required by some organisations before staff are allowed to carry out PAT testing. Achieving this qualification shows a sound working knowledge of the IEE Code of Practice. The "IEE Code of Practice for in-service inspection and testing of Electrical Equipment" sets the industry standard on how to carry out PAT testing in the workplace. 

Class I and Class II appliances

All electrical appliances using mains voltage have to provide at least 2 levels of protection to the user. This is to ensure that if one of the protection layers were to fail, there is the back-up of the second layer still in place. This makes electrical equipment very safe to use. Appliances can be Class 1 or Class 2. When PAT testing, it is important to first identify the Class of the appliance as Class 1 appliances are tested differently from Class 2 appliances.

Checking fuses in Plugs

This subject seems to always causes much confusion during our PAT Training courses - so thought about covering this in our first post.

During the course our advise is:

In a working appliance, if you find a 3 Amp or 5 Amp fuse then there is no need to change this. Just leave this in place.

If you find a 13A fuse, then check the power rating. This is usually found marked in Watts on the rating plate.