EBME Forums Forums Maintenance Test Equipment Difference between Pat Testing & Electrical Safety

Can you use an electrical safety tester to do PAT test or should you use dedicated PAT tester?

What kind of Portable Equipment are you testing ... medical equipment?

Either way, you need to decide what Standard(s) you intend to follow, then use whichever test instrument allows you to carry out the tests specified in the Standard(s).

Testing General Office equipment...

Indeed, you can use a medical electrical safety tester to perform portable appliance testing. Since the IET Code of Practice for In-service Inspection & Testing of Electrical Equipment (4th edition) states that the minimum requirement for suitable test equipment is to measure the earth continuity and the insulation, most medical test equipment will cover these tests.

However, you can't use standard portable appliance testers to perform tests on medical equipment! The IET CoP Scope (1.2.1) specifically excludes medical equipment.

Hello MikeX,

I was under the impression that when you PAT test, a higher voltage is used to measure insulation resistance which the safety test does not use?

No, the insulation test voltage is the same 500 V d.c. for medical and domestic.
(Reduced to 250 V where transient suppression devices are in use.)

If electrical safety means fixed wiring testing then it is is very different to PAT testing. Fixed wiring testing comes under the 17th edition fixed wiring regulations and involves testing the fixed wiring installation using an Earth Loop Tester, an RCD Trip Tester and an Insulation Tester, none of which can be used to test portable appliances(PAT)

You also missed testing the CPC (circuit protective conductor) by measuring the resistance.

As electricians tend to use a combined "all in one meter" that always include resistance and insulation why can't these be used to test domestic appliances?

You don't need a dedicated meter with these functions when you already have the measurement capability within you're existing test equipment. Clearly you don't have a nice mains socket on the tester to plug into but this is easily overcome (even ready made adapters are available for this function).

Permanently installed domestic equipment can also be tested using "standard" electricians test equipment since PE and insulation can still be tested.

In all cases testing should only be performed by those who are competent and in the case of testing electrical installations you will also need to be suitably qualified (Part P or BS 7671 , e.g. via City & Guilds 2393-10 or 2382).

In my understanding you can use whatever you like to test portable electrical equipment of any sort. The IET testing of portable appliances is a code of practice (and that's all) which you may adopt if you think fit. All you need to comply with the law is a system in place including documentation to show that you have methods to ensure that the equipment is electrically safe, how and when you choose to do that is entirely up to your risk assessment.