Leakage Current on Class two equipment

[ceraunic_level]

Don't know if I am having a bit of a brain freeze, but measuring earth leakage current on class two equipment.

Is the machine (in this case a PAT Tester, kewtech KT71) measuring the difference in the phase and neutral and calculating that any difference is leaking to...somewhere!!

thanks

 

[ericmark]

I don't know your PAT machine but I know with items like drills which have large lumps of metal then I would connect the wandering earth lead and check for leakage which if the drill had been left in a pool of water is possible although unlikely.

The Robin PAT machine I used allowed you to enter extra test types but the leakage function only worked while the item under test was running so no point in clipping on to a chuck etc. And in most cases the leakage test on class II was pointless and was omitted from the test.

And yes with the machine I used it was measuring the difference between line and neutral.

The biggest problem is when one machine is both class I and class II this was the case with mag mount drills where the drill was class II but the mag base was class I and I found a few results submitted when the earth continuity had not been tested. The tester had seen the double square and assumed whole item class II.

 

[ceraunic_level]

Cheers ericmark

New to PAT testing and I quite like to do the leakage test instead of IR for IT equipment, and other things like microwaves, and washing machines etc that may have a PCB.
But when it come to class two I was wondering what's the point, if you don't have a protective conductor. But the imbalance between phase and neutral makes sense. I guess the difference could appear on the outer casing/metallic parts ?? via some earth path in the device??

 

[ericmark]

In the main class II equipment is only inspected. I had to plug it in and go through the question and answer system on PAT tester as it was all auto down loaded but really it was a waist of time. This is why with the fully automatic all singing dancing I could only get about 60 tests per 8 hour day but with manual model one can get up to 200 although I have seen claims of 300 per day to me they must just stick on a label and nothing more.

On first doing an area one had the problem of noting down all the details so a little slower second hit we only had to enter in plant number. However I know one large testing firm takes no notes as to what each item is and gives them a different plant number at each test.

For me it was in house testing and it was a fall back job when we were not busy and there was no pressure to do it fast. We took the attitude that plugging something into a PAT tester was far easier than opening it up and using ohm meters and ELI meters to do same job so unless it was not possible as for example with a washing machine where one would need to let it complete the whole cycle connected to PAT machine to test without removing covers, then we used PAT machine.

However some companies only PAT test items which are classified as portable and walk away leaving many items untested. Hand driers are a real pain to test and time consuming and if charging by item I can understand why they are missed.

The manager is responsible to ensure all items are inspected and tested and he needs to arrange for special test arrangements for example the photostat machine is often under maintenance contract.

For us as electricians it is important for us to know where our responsibility ends. As an in house electrician I was responsible for it all including arranging for maintenance contracts so it was no problem but as a contractor it can be a real problem. My son arranged to do some PAT testing and first batch was great but then they would ring up. "Just got a new XYZ will you call in and PAT test and enter it on register" and he had forgot to put in a minimum charge.

Glad to say I no longer do it.

 

[ceraunic_level]

I know what you mean, I have the basic entry level PAT tester but I am finding I prefer to use, and trust more my MFT.

Cheers.