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I have been following a heated debate on this subject ,its been suggested to I.R test circuits before cu change.if doing so are you testing through main tails or individual circuits both would involve lamps out sockets and appliences dissconnected this would take time and could risk damage to sensitive circuits that you have missed, i put a tong meter on the main earth tail from the cu to the meter and check to see if there is any amps present if so i have a earth fault on the installation i would then scale down testing to find the circuit with the fault this of cause would not show up if the cu has no rcds but would as soon as you fire up the nice new cu with nice new rcds it works for me i am at present on 2391 and this subject is a good one
 
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L

lionelmcc

good call
I always worry about missing something on IR tests and usually join the phase and neutral together and test between them and earth.
Unless I really know the property and installation well, or if it's my install, I get this niggle before I push the test button
 
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G

Guest123

Sorry guys, I aint gettin involved with this one dont know who I might offend!!!:eek:. My views are in the other thread.:)
 
  • Thread Starter Thread Starter
  • #4
HI LENNY
You will get no slagging from me i appreciate all the help you and the other sparks offer on here i am new to this trade and setting up on my and this site is a great source of information for me and others like me do you go with my testing method of using the main earth to check for any leakage of amps to earth with tong meter
 
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Guest123

Yeah, it absolutely makes sense. The only thing I would say is to make sure that all high leakage appliances such as computers, heating appliances and other resistive loads are removed from the circuit as this may give a false indication of earth leakage on the circuit and you could possibly go looking for a fault that isn't there.

Have you got one of those nice earth leakage clampmeters that will measure milliamps??
 

diditrain

-
Arms
One bit of advice is to test at 250volts first. That way you will identify if a load is still connected if you get a poor reading between phase/neutral. Then crank it up to 500 if everything is ok at 250
 
  • Thread Starter Thread Starter
  • #7
Allways tricky this one I.R on cu changes!! thanks lenny and also trainy graet idea about buzzing 250vs simple ideas like that can save me time and money keep up the good work
 
L

lionelmcc

I'm with Tuckermot

I'm not into slagging off people for trying to be helpful. and, like tuckermot I am trying o get going myself
I'd like to extend my thanks to all who posted on this site
 
S

Spudnik

I get this niggle before I push the test button
Once you get going that feeling soon disappears.

Like others have said, test at 250V first to make sure everything is disconnected.

If you get a flat reading anywhere, then its possible a spur is hidden away somewhere still switched on, or there is an outside light with a PIr sensor on it.
 
S

Spudnik

Alright Lenny, you got me hooked, where's the other thread?!!

Cheers, Ron
Apologies Ron,

Its now been archived.
 
R

ron55

Apologies Ron,

Its now been archived.
Actually I did find it before you "archived" it. It was titled "what tests do prior cu change" and the guy you took a dislike to had some pretty good points presented in an orderly manner.

In real terms you censored it because he criticised a moderator. Weather he was right or wrong have you never heard of free speech?

Cheers, Ron
 
S

sivoodoo

Shouldnt we be checking for continuity on circuits before we zap em with IR? If theres no continuity then our IR will be a false positive.
 
G

Guest123

Actually I did find it before you "archived" it. It was titled "what tests do prior cu change" and the guy you took a dislike to had some pretty good points presented in an orderly manner.

In real terms you censored it because he criticised a moderator. Weather he was right or wrong have you never heard of free speech?

Cheers, Ron
Ron, I'm sorry but you are way off the mark here. The guy launched what I felt was a personal attack on me implying that I was a joke and no good at my job.

All I was doing was sharing my input on the op's query and not metioning anything about him, and for whatever reason he took great offenece to it and launched his tirade against me.

I'm all for free speech Ron, but not when it doesn't relate to th OP and certainly not when it berates another member of the forum.
 
R

ron55

Ron, I'm sorry but you are way off the mark here. The guy launched what I felt was a personal attack on me implying that I was a joke and no good at my job.

All I was doing was sharing my input on the op's query and not metioning anything about him, and for whatever reason he took great offenece to it and launched his tirade against me.

I'm all for free speech Ron, but not when it doesn't relate to th OP and certainly not when it berates another member of the forum.
Hi Lenny

I probably am off the mark as I really only skipped through the post pretty quickly - it was pulled too fast :):). When I wrote the reply I couldn't look at it again. Personally I would have responded against an attack but I don't have the delete button as an option.

That said, from what I have seen on here over the last month I think anyone describing you or your abilities as a joke is very misguided as you obviously know the trade inside out.

I thought the thread had some good points and it begs the question - can't individual replies be pulled?

Cheers, Ron
 
L

lionelmcc

This is an unfortunate situation. And the the guy did have some valid points. But he did get personal , and I'm with Lenny, as this is unnacceptible.
However I don't think the thread should have been pulled as he was not making Lenny look bad - it was him that "blew a fuse"
 
S

Spudnik


This is a very good topic, and many people have differing and interesting views, which we could all benefit or even learn something from, therefore, can we please stick to the OP's query.

The other thread has been pulled. End of.

KEEP IT CIVIL.

Thank you.




 
J

johnnyb

I agree Jason, there does seem to be some very differences of opinion, this has been a cracking debate, and yet we all seem to be going aaround in circles somewhat, know its been pulled other people cannot really see what the debate is all about, do you think you could very simply break it down and re-issue a laymans term possibly and other lads can see what it was about.
My own opinion is , although yes it remains the fact that you would have to un-plug and take lamps out, i would still do an I/R test, it sorts the lot out then, you can see straight away what problems there are, before you do a C/U change, and then you can verify with the customer the costings appropiately and everyones singing from the same hymn sheet.
 
G

Guest123

My own opinion is , although yes it remains the fact that you would have to un-plug and take lamps out, i would still do an I/R test, it sorts the lot out then, you can see straight away what problems there are, before you do a C/U change, and then you can verify with the customer the costings appropiately and everyones singing from the same hymn sheet.
Thats all I was trying to say, I wasn't trying to force my opinion on anyone just giving my take on the OP, nothing more.
 
I

iceman

hi just wondering when carryin out an insullation resistence test with the old wiring colors black neutrel red line if the metre is set on mega ohms scale 500v dc and the scale goes to 2.95 would tht be a pass as its over the 1 meg ohm minimum cos i was thinkin the scale had to go all the way across? my tester is the 1502/2 megger multi fuction tester any help would be great
thanks
 
S

sivoodoo

Thats a very low resistance reading iceman, it would need further investigation.
 
I

iceman

thts wot i thought i gotta go bk 2moz and find the fault, i did a board change supplyin ring circuit 3lights circuits everythin else i tested was ok went the full range on me tester, i got good reading for R1 + R2 im surprised nothin showed up on thm eather, appently the guy who lives at the house did the wiring himself got me round to fit the board theres no way im takin responsablity for is job so i issued him with a pir insted.
 
S

Spudnik

The previous thread has been edited and opened to view for reference only, as requested by a few members.

I will be keeping a close eye on this thread although i do welcome a good debate.



 
R

ron55

What attracted me to this thread in the first place was a bad experience last week and begs the question where do you stop with pre testing.

I changed a CU for a friend and it turned into a nightmare. The IR readings prior to the change were fine so ahead I went as I always have done. The problem came with the end to end L-L, N-N & cpc-cpc continuity tests on the ring. The L & N were fine but the cpc was open circuit. I figured just an earth fell out of a socket.

However every socket had an earth present shown by a tester. The fault took over half a day to find and rectify and was found by linking the 2 neutrals and one cpc together and then doing a N-CPC continuity test on every socket. I found 6 sockets without readings and the fault turned out to be in a JB under a carpet covered chipboard floor where a spur had been added and one cpc was just not connected. Oh, I forgot to mention it was just one ring throughout the house with the exception of the kitchen, about 30 sockets in total.

So although every outlet had a cpc the worrying thing is that the broken cpc ring means not enough current carrying capacity in event of a fault.

After a 9 hour job the upshot is that in future I would virtually do a complete test before a change never mind just IR.

Cheers, Ron
 
S

Spudnik

Hi Ron,

When testing the RFC R1+R2 cross connected at the CU, and then going round all the sockets, this should have highlighted the problem.

An IR test would not pick this up as there was a break in the circuit, which to be honest, probably made the readings quite good!
 
L

lionelmcc

I think this is a good decision Jasonas most of the members do not seem to involve themselves in personal abuse. And alhough the guy had some good points I think it will vindicate Lenny as he was only trying to put his point across.
In my opinion the other guy took offense at Lenny's point of and things got out of hand

Most unfortunatre
 
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