Long term PIR testers question?

[Steve34]

hi guys,
I was gonna do my pir in exactly the same way as i do initial verifications, unplug all loads, disconnect voltage sensitive equipment etc etc... but have been told some testers do things i found very confusing, ie:

When doing the IR test only do N-E, as any problems betwen L-N and L-E would have caused a fault and the client would've had someone round to fix that already?

Don't bother taking the earthing conductor out to do your Ze as it can be a b*tch to put back in the earth bar especially on a badly done board, the reasoning is the suppliers earth was proved by initial verification, and the system has always worked perfectly well with the parallel earth paths, also the parallel earth paths actually make your reading look better?

But the one that threw me the most was, as long as they get a good reading on sometimes as little as 25% of the install, they pass it and just right only 25% checked in the limitations, and this is acceptable?

I'm just looking for some clarification, now i know none of the professional testers on this site would do such things so i'll phrase my question as; exatly what tests would your "friend" do and how would he do them? Thanks.

 

[Davey101]

IR test- I presume whoever told you this was an 'old school' spark. There is 'some' truth (i.e almost none) in this, but its a bit like saying you dont need an mot to tell you your car is safe, as the fact you havent crashed proves it is.
L-N tests are often omitted, to avoid damaging sensitive kit. This should be noted as a limitation.

The one about the Earth is a load of rubbish, you can't just not do a test because its tricky. Parallel paths are the reason you dissconect the main earth. Sometimes you cant, because you can't turn the supply off, I've done this in the past, not saying its right, just not uncommon with sparks I know.

Be carefull that the client understands that you are only doing 25%. A lot of companies, especially in council/goverment type buildings want a full test done, dont get caught out, it will be an expensive lesson!

 

[Des 56]

Steve34

The advise I would give you ,is to go about all your pir testing with the intention of knowing that the installation is safe
If you cut corners you can never do that

There are quite a few routines and means of testing for safety that dont come out exactly as the comfort zone dudes who write the guidances expect
You mentioned IR testing,whilst nowadays this is not the most vital of tests with RCDs here there and everywhere it is still necessary
It can be done phase and neutral together to earth in many cases

Always obtain the true Ze
By not doing so, the reading that you get, may be through a metal incomer service, that may be changed in the future,you are then leaving them with no earth and a potential executioners axe,provided by you
Do not listen to those sort of, how best can I not do the pir, but find your own way with safety in mind

Testing 25%
They may be getting mixed up with the agreed limitations ieLimitations agreed with the client, 40% accessories removed for inspection,This does not mean the rest can be left untouched rather what it says is inspect that percentage and increase it if there are problems found, but test 100% especially domestic,there is no reson not to

 

[Steve34]

Thanks for the reply guys, i'm glad you both said that, i just didn't feel comfortable skipping what i've been led to believe are important tests.