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Tricky PAT question

TrigPoint
Hello everybody! I could use a bit of sage advice regarding PAT testing unusual items.


To give you a bit of background, I'm in a bit of a tricky spot because I just took over a role as a PAT tester and it came with two very smart testing devices which save the identification number, create a bar code and save the tests required for whatever item it is. Subsequently everyone in my company seems to think that all I have to do is type in a number and the test is automatic.


Unfortunately, the more items I test, the more I notice that the tests that have been inputted, are not anything I want to put my name/initials to. I mean, a few days ago I was prompted to complete a touch current test on a bog standard class I toaster. I've found; tests on leads that do not test for polarity, a test that checks IR at 500V and also checks leakage but nothing else, and it seems to have been standard to cobble together 4 and 5 pin plug and socket adapters for testing 35/63/125A cables using 3 pin plugs and sockets which connect to the PAT tester... d'oh! So it's taking me a lot longer to test things than my company expects. It's a bit of a nightmare if I'm honest as almost every test needs checking and most need reprogramming. 


To make the problem worse, it seems my bosses really trusted the person who was doing this before me and so every time I run into a problem or a test that doesn't work properly, sometimes in front of them, it's sort of taken as me being incompetent rather than the test being substandard in the first place. So, I can't really ask my colleagues for advice because it kind of works against me. So that's why I joined here and I'm asking you. Thank you for reading this far by the way. I'll get down to the real question now...

I test everything from museum exhibits and set for TV shows to your average kettles, toasters, microwaves and so on. But occasionally something comes up with a lot of exposed painted metal which is earthed using an earth nut. In this case it's a booth for a TV game show. How would one decide what a suitable resistance might be for such items during an earth bond test? Also what are the implications for Insulation resistance? You'd think it would fail because of the large amount of metal with no real insulation on it connected to the circuit. This has me beat! I have no idea what to do to test it properly.

If anybody out there has any advice I would really appreciate it.


Thanks


Trig  


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  • 0
    I also find myself on the end of a PAT machine these days Trig,  having obtained the C&G years back and ignored it as too dull.   I suddenly became the only qualified person on the block during an emergency to update some PAT so off I went to a remote beach in Wales for a week to test a load of our off site bits -computer racks and scopes, radiators, fridges, power tools and all sorts.  I took with me the new Fluke 6500-2 and an old Seaward SuperNova. Fortunately I also took the new Megger 1741.


    What are they thinking?  25Amps on a class one appliance?  That's live working isn't it?  I was horrified.  On one or two bits the earth clamp had to be held to stop it falling off and I swear I can feel it vibrating as it tests.  If you use the auto setting the appliance even tests itself and, for example, the pump you are testing comes on.  Woah!


    I ended up by doing a fair amount of the tests using the old fashioned method of testing the earth bonds and a gentle IR test wherever I though it was appropriate.  On some I used the Megger MFT just to confirm earthing etc.   The Fluke is brilliant for IEC leads but the tests are not intuitive so it will take some getting used to.  The Seaward is, well, a bully.


    I came back and sat down with a colleague to say that I think PAT is absolutely brutal, should be classed as live working and that our regime needs modifying.


    None of that helps if you are working for an organisation that want to see the downloaded results and that said brutal menu of test choices have been used.  Fortunately they took my views on and are happy with my 'limitations'.   I blew up one oil filled rad by the way.  Class one but the thermostat will never work again I reckon.


    Zs
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  • 0
    I also find myself on the end of a PAT machine these days Trig,  having obtained the C&G years back and ignored it as too dull.   I suddenly became the only qualified person on the block during an emergency to update some PAT so off I went to a remote beach in Wales for a week to test a load of our off site bits -computer racks and scopes, radiators, fridges, power tools and all sorts.  I took with me the new Fluke 6500-2 and an old Seaward SuperNova. Fortunately I also took the new Megger 1741.


    What are they thinking?  25Amps on a class one appliance?  That's live working isn't it?  I was horrified.  On one or two bits the earth clamp had to be held to stop it falling off and I swear I can feel it vibrating as it tests.  If you use the auto setting the appliance even tests itself and, for example, the pump you are testing comes on.  Woah!


    I ended up by doing a fair amount of the tests using the old fashioned method of testing the earth bonds and a gentle IR test wherever I though it was appropriate.  On some I used the Megger MFT just to confirm earthing etc.   The Fluke is brilliant for IEC leads but the tests are not intuitive so it will take some getting used to.  The Seaward is, well, a bully.


    I came back and sat down with a colleague to say that I think PAT is absolutely brutal, should be classed as live working and that our regime needs modifying.


    None of that helps if you are working for an organisation that want to see the downloaded results and that said brutal menu of test choices have been used.  Fortunately they took my views on and are happy with my 'limitations'.   I blew up one oil filled rad by the way.  Class one but the thermostat will never work again I reckon.


    Zs
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