IR Test

[Jay Sparks]

Hi lads, Just want to pick your brains . When you do an IR test and you cant disconnect current using equipment for what ever reason, the regs say you can connect line & neutral together and test to earth. Where would you put the result in on the test sheet? Line/Line or Line/Earth, and do you leave the other blank? Only when I worked for a company testing re-wires and I could not dissconect current using equipment, I did this test and they still wanted me to put a result in both box's. Any comments would be great.

 

[markharris]

I got taught you don't IR test between neutral and line if you are unable to disconnect any loads, as you might damage them. Only test between line/earth and neutral/earth, line/neutral remains blank, and a note is made in the remarks column to the far right of that circuit's row on the test sheet, and a note is also added in the extent of limitations box

 

[Jay Sparks]

In the 17th edition and guidance notes 3 it says you can connect the line and neutral together and test between them and earth if you cant dissconect a particular load. This prevents the load being energised by the 500v and does no damage and still tests the insulation resistence but it doesnt tell you were to put it. On an NICEIC test sheet it has three sections for the IR reading. I always put >299 in all.

 

[Deleted member 9648]

I always put >299 in all.

Wot even if you get a reading of 2 ohms?

 

[Jay Sparks]

Obviously not. The installs i was testing where new and so most of the time it was >299 anyway but some times I could not dissconect a load and so the reading would be inacurate, but when I connected the line and neutral together and tested to earth it was >299. But the company I worked for wouldnt accept the test sheet unless all 3 box's where >299 so if Id only tested between line/line connected and earth on a particular circuit then I would still have to put >299 in line/line, nuetral/earth and line/earth. Do you see why I asked the earlier question, were do you write the results for this test. And sorry for the spelling, its bad.

 

[Sintra]

Obviously not. The installs i was testing where new and so most of the time it was >299 anyway but some times I could not dissconect a load and so the reading would be inacurate, but when I connected the line and neutral together and tested to earth it was >299. But the company I worked for wouldnt accept the test sheet unless all 3 box's where >299 so if Id only tested between line/line connected and earth on a particular circuit then I would still have to put >299 in line/line, nuetral/earth and line/earth. Do you see why I asked the earlier question, were do you write the results for this test. And sorry for the spelling, its bad.

On a new install EIC you are not permitted to have any limitations on the testing and inspecting. There is no excuse not to disconnect loads as the IR testing should be done before any loads are connected.

On a PIR state as a limitation that you can not disconnect sensitive equipment and fill in the Line/Line IR column with LIM (limitation).

 

[Jay Sparks]

The last company I worked for did full rewires in a day while it was occupied. Then I would be sent round about 2 weeks later to test, so the install had been in use for 2 weeks. The rewire team did there own little test to make sure it was all ok but that was for there piece of mind. I have learnt one thing from working for a couple of different firms and remembering what my old tutor used to say, QUOTE: " Theres the right way of doing things and the practical way" my old boss said as long as the practical way is safe and doesnt deviate from the regs its ok.

 

[Mark.W]

But the company I worked for wouldnt accept the test sheet unless all 3 box's where >299 so if Id only tested between line/line connected and earth on a particular circuit then I would still have to put >299 in line/line, nuetral/earth and line/earth.

You wouldn't put any results in Line/Line. It would be Line/Neutral, Line/Earth and Neutal/Earth. The reason you'd fill all 3 boxes is because you have tested the whole cable (both conductor and CPC),
If you connect line/neutral and test to earth, the reading you get will be lowest of the 3, so because you got >299 that means the lowest is still >299.
If you had tested them all seperately ie, line/neutral, neutral/earth and line/earth you would have gotten >299 on all of them.

Hope that helps!

 

[miner69er]

personally i don't fill in all three boxes as this suggests three seperate tests.
On the Line-Neutral box, write "to earth" next to or underneath Line-Neutral so it is obvious on the paperwork the test you have done. This is the way i do it and when i pointed this out on my first assessment it was given the O.K. by the Elecsa assessor.

 

[Jay Sparks]

Thanks Mark.W thats what I thought. When I said line/line I meant line/neutral, must of had a dumb moment. So you would still fill in all 3 of them. Thats ok then cos thats what I was told to do anyway. Cheers guys for the feedback.

 

[scotsparky]

when i do it on a 3 phase circuit for example its

line line = Lim unable to tedt.
line neutral = lim phase neutral linked so no test.
neutral earth =i nsert result done at same time as line to earth
line earth= insert result. done at same time as neutral to earth

 

[WayneL]

The last company I worked for did full rewires in a day while it was occupied. Then I would be sent round about 2 weeks later to test, so the install had been in use for 2 weeks. The rewire team did there own little test to make sure it was all ok but that was for there piece of mind. I have learnt one thing from working for a couple of different firms and remembering what my old tutor used to say, QUOTE: " Theres the right way of doing things and the practical way" my old boss said as long as the practical way is safe and doesnt deviate from the regs its ok.

Unbelievable!

It does deviate from the regs because an installation should be fully inspected and tested, and certificates issued, before being energised and put into service - what if there had been a serious fault on the wiring??

What were the install team relying on - the good old 'bang' test?

 

[Jay Sparks]

No they actually did the proper tests and gave the test sheet to the site manager but they didnt do a full inspection. Dont ask why it was done this way but everyone seemed to accept it as the norm. And who would listen to me fresh from college.