insulation resistance on a ring main

[vertigodj]

if someone could just clear this up please, when doing a insulation resistance test on a ring main, be it between live conductors, or between live conductors and earth, would i be correct in saying that you put the crock clips on both live conductors of the circuit and test or just one single line conductor and conduct test

 

[Click-Sure]

Would it make any difference?

 

[RF Lighting]

It shouldn't make any difference, assuming you have verified ring continuity

 

[vertigodj]

i don't think so, have tried it and get same readings, still learning so just making sure what i'm doing is correct

 

[oharaf]

Take one leg of the ring final

connect clips to

1. Phase & Neutral - Test

2. Phase & Earth - Test

3. Neutral & Earth - Test

If you connect to either end of a leg you will create a dead short

You could connect Phase and Neutral together and attach to 1 clip and earth to the other and test, however I consider this to be lazy and not GOOD practice, you should do the test in pairs in my opinion.

I know people who do this but it is surely quicker to just do it in pairs!!!!

 

[scousespark]

Connecting phase/neutral is recommended when you have any sensitive equipment, such as neons, if you can't disconnect them.

 

[oharaf]

Yes, i know that is one reason for doing IR in this manner

 

[333rocky333]

If nothing vulnerable on circuit.

I would do each coloured end seperate that way you test each loop twice and can compare the readings.

This would also indicate lack of continuity at the same time, if one reading was significally different for the same colour core.

Same with the N and E.

 

[flameport]

Continuity tests are done before insulation resistance.
Therefore it doesn't matter which end of the ring insulation is tested from, since you will already know that the two ends are connected.

Insulation tests are also done with the protective conductors connected to the main earth terminal.

 

[scousespark]

Yes, i know that is one reason for doing IR in this manner

Fergus, my reply was meant for Vertigodj.
Sorry if it appeared to be a dig at you.

 

[ricicle]

Just don't touch the other two ends when you are IR testing the opposite ends !

 

[ban-all-sheds]

No - that's what apprentices are for.

 

[ColJack]

Insulation tests are also done with the protective conductors connected to the main earth terminal.

where does it say to do that?
what's wrong with testing the wiring in isolation from the CU?

I assume you think it proves that the L/N hasn't been damaged and touching the conduit or trunking or the water pipes under a floor etc?

 

[GaryMo]

Insulation tests are also done with the protective conductors connected to the main earth terminal.

where does it say to do that?
what's wrong with testing the wiring in isolation from the CU?

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