Supply Point Earth Loop Impedance Testing

[squadman]

Re: Supply Point Earth Loop Impedance Testing

Something else to consider here, it is evidently standard practice with a certain manufacturers service that should a earth impedance test fail then there is no further work provided until the earth is restored to the required spec.

In essence if the electrical system fails a ELI test the engineer leaves. Is this common with BG I wonder ?

I would not have thought that the reason that ELI tests are becoming common is due to the fact that additional work is being drummed up but it is to test the quality of the earth which a martindale does not do hence the need for a ELI tester.

[RocketMan]

Re: Supply Point Earth Loop Impedance Testing

Product codes 13485 Classic MARTINDALE Plug-In Socket Testers
and 15166 Non-trip Earth Loop Impedance Checker (about half way down the page)
http://www.bes.co.uk/products/192.asp

Really checking using the classic Martindale should be about as far as you go surley? After that are you not getting into the realms of Part P testing.
(yes I know classic Martindale doesn’t test the quality of earth !!)

And oh yes lots of engineers don’t even have a mega. When I started working for one of the big sheds I refused to do any more work until they gave me a mega. One of the senior engineers eventually gave me his. Brand new, still in it’s box and wrapped in a sealed plastic celophane bag. He’d had it about five years since he’d been at that service centre…… Two years later before I left, he still didn’t have one!! And this guy often stood in as white goods service manager……. said it all really about the guy.

Steve

[kwatt]

Re: Supply Point Earth Loop Impedance Testing

You give engineers a megga and they write on the sheet… 0.001 or whatever answer is required.

End of story.

Unless there’s cause they won’t generally carry it into the house along with the toolbox, laptop, phone, parts they think they need and so on.

My thinking, if it doesn’t fit in the toolbox (like the Martindale plug tester) engineers just won’t bother with it. If they need it to prove a point or because there’s a cause to use it then they invariably will, but as a rule, most engineers won’t go looking for problems, just sort them when they find them.

It may not be a politically correct view, but it is a realistic one forged from years of experience. The reason that you give them the gear and show engineers how to use it is to cover your own a$$ as an employer or sub-contractor, you know damn well they won’t use them when you fork out the cash for them.

“We do the job right M’Laud” does not prove that you did or didn’t carry out the relevant testing, it only says that you say you did it. Prove it. Merely having the equipment is no prove that you did, or even know how to, carry out the tests whether you did or didn’t. You could have just written the relevant numbers on the sheet or tapped them into the PDA or laptop, that’s not proof.

Re-calibrated… what’s that then? 😉

K.

[neilsukwg]

Re: Supply Point Earth Loop Impedance Testing

Found a useful leaflet that covers everything written here
http://www.hse.gov.uk/pubns/eis35.pdf

What ken said about convinience,

My thinking, if it doesn’t fit in the toolbox (like the Martindale plug tester) engineers just won’t bother with it.

is very pragmatic but fortunately, and for less than £50 I can now have piece of kit the same size as my £10 plug in tester that will check the quality of the earth without tripping the rcb.
rocketman

Product codes 13485 Classic MARTINDALE Plug-In Socket Testers
and 15166 Non-trip Earth Loop Impedance Checker (about half way down the page)

http://www.bes.co.uk/products/192.asp

http://www.pat-training.co.uk/socket_testers.htm

I was going to order one right away but the shops open in a couple of hours and I want one now ❗

[shonight]

Re: Supply Point Earth Loop Impedance Testing

it gets recalabrated once a year and they come to us to do it

good or what

[maltheviking]

Re: Supply Point Earth Loop Impedance Testing

neilsukwg wrote:Found a useful leaflet that covers everything written here
http://www.hse.gov.uk/pubns/eis35.pdf

Now where have I seen this before?
😉

[Grendal]

Re: Supply Point Earth Loop Impedance Testing

I do an eli check on every job only takes a miute to do and it gives you complete piece of mind when you walk away from the job that you have left the appliance safe and I can sleep at night

[neilsukwg]

Re: Supply Point Earth Loop Impedance Testing

was it here ?
http://www.ukwhitegoods.co.uk/modules.php?name=Downloads&d_op=viewdownload&cid=1&min=10&orderby=titleA&show=10

What is originality? Undetected plagiarism.

[spanner51]

Re: Supply Point Earth Loop Impedance Testing

Doing an earth loop impedance test is always good practise, however unless you understand the reading, and have an electrical qualfication i.e City & Guilds 236/238 or equivalent then the test is meaningless.

[maltheviking]

Re: Supply Point Earth Loop Impedance Testing

spanner51 wrote:Doing an earth loop impedance test is always good practise, however unless you understand the reading, and have an electrical qualfication i.e City & Guilds 236/238 or equivalent then the test is meaningless.

And can be a very dangerous test if you are not sure of it’s use.
If there is a loose or poor main earth then the 25 amp test can find a different route, but so can a earth bond test 😉 the plus side is in the right hands it is an invaluable test.
Point in case, yesterday I discovered a whole series of sockets in a kitchen with no earth, a martindale may not do this, a resistance check with a basic megger may not have shown this either 😕

[Grendal]

Re: Supply Point Earth Loop Impedance Testing

Point in case, yesterday I discovered a whole series of sockets in a kitchen with no earth, a martindale may not do this, a resistance check with a basic megger may not have shown this either
I too had this yesterday 4 sockets in the kitchen no earth been like that for a year martindale did not show up the fault

[kiddo66]

Re: Supply Point Earth Loop Impedance Testing

I use a Seaward tester which is a cracking piece of kit and “compact”enough to keep in my tool case but a lot of my fellow engineers are using the socketandsee testers and finding them easy to use and under 300 quid.
On the question of loop Impedence testing i seem to remember from my apprenticeship that to do this test properly all earth bonds in the property should be disconnected,Indesit started to do Impedence checks then reverted to doing an earth resistance which i think proves existence of a good earth just as well,lets remember we are there to repair an appliance not rewire the house and most comments ive made on an installation are met with a blank look.

[Pigpen4]

Re: Supply Point Earth Loop Impedance Testing

I issued a Supply Failure letter to a customer last month, because her earth loop impedence was between 10 and 100 Ohms on my Martindale “E-Ze Check Xtra”.

I had a phone call from her nephew today, accusing me of scaring his auntie unnecessarily with my paperwork.

I explained to him that, in accordance with the 17th Edition Regulations, it should be less than 1.2 Ohms, to which his response was something along the lines of:
because there is an RCD consumer unit fitted, you are allowed an earth reading of up to 200 Ohms, as long as it trips the RCD.

I was in the middle of a call-out at the time and did not want to create a fuss in her kitchen, so I told him that I’d look into it and mend my ways if I was at fault, thanking him for his advice.

The thing is, I’ve just checked my Dixon Training Notes and I’m pretty sure it should be less than 1.2 Ohms. (but to expect readings of up to 5 Ohms on some older, overhead-wired houses, if I remember Graham correctly).

He said the actual reading on his meter is around 60 Ohms and he’s been trained by British Gas, so he should know what he’s talking about.

Is there any truth in what he’s saying?
Is there an instance when a reading as high as 60 Ohms could be allowable?
Or is he getting confused with an RCD having to cut off power within 200 milliseconds?

There must be a 16th or 17th editioner out there with the answers ……….. please?

Pigpen.

[maltheviking]

Re: Supply Point Earth Loop Impedance Testing

The nephew must be the same pratt who phoned me a couple of weeks ago and asked me to keep my opinions to myself. I’m an electrican he anounced, your just an washing machine repairer and I should stop frightening customers. 👿 That realy got my back up. Basically “the” electrician had changed the earthing type to the property from PME (old money)now TNCS to TT(Earth rod)his mistake which I informed him was that he hadn’t issued a certificate, and changed the labeling at the earth source. He got a bit of a shock when I pointed this out and that I am also an electrician in my past life.
The Earth Loop reading I took was over 120 ohms, for PME earthing it sould generaly less than 0.87ohms for socket outlets. As he had installed a seperate earth rod system(TT)then 120 ohms is OK , less than 200 ohms is acceptable.
My final one was to ask him if he was registered with Niceic, as I would need his number to have a word with them about the non certification issue. Just a “washing machine repairer” in deed.
How to win friends and influence them :rolls:

[Pigpen4]

Re: Supply Point Earth Loop Impedance Testing

Perhaps it is the same one, Mal!
Anyway, this village got converted to underground electric supply in 2006, so would I be right in assuming her house would now be a TN (PME) system?

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