Insulation resistance testing

[Bradley6969]

Hi have AM2 next week and just need some help, 3 phase TP+N board, two way and intermediate lighting circuit with 3 switches obviously and one light, doing a global IR test, the lighting circuit say is on L1, so I’m testing all other circuits at once too do I have to switch my switches for every one of these tests
L1-L2,L1-L3,L2-L3,
L1-N,L2-N,L3-N,
L1-E,L2-E,L3-E, N-E

 

[westward10]

Yes you need to do it through all switching possibilities.

 

[Lucien Nunes]

I'm not sure what the 'official' procedure for the AM2 is but from an electrical viewpoint, you test all permutations of 2 or 3-way switch positions to make sure each of the strappers and the SL get included in the test along with the PL. But they are only associated with whichever phase the lighting circuit is on, L1 in your example. So, if the switch wiring is not present in any accessories with any of the other phases, there would be no benefit changing the switch positions when testing L2 or L3 as the strappers and SL can't be faulted to those phases.

 

[Bradley6969]

I'm not sure what the 'official' procedure for the AM2 is but from an electrical viewpoint, you test all permutations of 2 or 3-way switch positions to make sure each of the strappers and the SL get included in the test along with the PL. But they are only associated with whichever phase the lighting circuit is on, L1 in your example. So, if the switch wiring is not present in any accessories with any of the other phases, there would be no benefit changing the switch positions when testing L2 or L3 as the strappers and SL can't be faulted to those phases.

Ok thanks so if circuit is on L1 I’ll do,
L1-N,L1-E,L1-L2,L1-L3

So say if I do L1-N I’ll do,
Switch 1 ON test
Switch 2 OFF test
Switch 3 ON test then,
Switch 3 OFF test
Switch 2 ON test
Switch 1 OFF test
Then do the same for others

 

[kingeri]

Yes I find running around flicking switches a pain, I tend to keep a note as I am going so I don't lose track.

 

[telectrix]

so glad i'm getting outof it after 50 yeaqrs. back in the day, it was wire it, connect it....if it went bang, then tester came out.

 

[westward10]

Ditch the switches and whack them in Wagos.

 

[westward10]

Ok thanks so if circuit is on L1 I’ll do,
L1-N,L1-E,L1-L2,L1-L3

So say if I do L1-N I’ll do,
Switch 1 ON test
Switch 2 OFF test
Switch 3 ON test then,
Switch 3 OFF test
Switch 2 ON test
Switch 1 OFF test
Then do the same for others

I haven't drawn it out but you only need to find positions where each of the line conductors will have been zapped.

 

[Bradley6969]

I haven't drawn it out but you only need to find positions where each of the line conductors will have been zapped.

Could you draw it out please if not don’t matter I’ll just use that way

 

[westward10]

Just sketch out the three switches and draw through the line conductors until all have been covered, those will be your combinations.

 

[westward10]

I have only done it in my head because I just link them together, but one test with them in one position and another with them all switched the other way, am I correct?

 

[Risteard]

Do the tests. Reverse all switches and test again.

 

[Risteard]

I have only done it in my head because I just link them together, but one test with them in one position and another with them all switched the other way, am I correct?

That's the way I do it. It beats performing 48 different insulation tests on the installation!

 

[Bradley6969]

Ok thanks guys, the lighting circuit is feed to first switch then 3 core between switches then from last switch to ceiling rose so what I’ll do is,
Switch 1 off
Switch 2 on
Switch 3 off then test

Then Switch 1 on
Switch 2 off
Switch 3 on then test

So will I still have to do this for L1-E, L1-N, L1-L2,L1-L3

 

[Risteard]

So will I still have to do this for L1-E, L1-N, L1-L2,L1-L3

Or...

{L1+L2+L3+N} to E.
{L1+L2+L3} to N.
Then between phases.

 

[westward10]

Doesn't really matter what position you have them in for the first test as long as you switch them all the other way for the second but yes you are correct.

 

[Bradley6969]

Or...

{L1+L2+L3+N} to E.
{L1+L2+L3} to N.
Then between phases.

I’m just on about when I need to switch my switches as lighting circuit is only on L1

 

[Bradley6969]

Doesn't really matter what position you have them in for the first test as long as you switch them all the other way for the second but yes you are correct.

Thanks for your help

 

[westward10]

Not sure about others views but I was always told when a switch is connected for two way operation it is never off or on, the lamp may be off but the switch still provides an output no matter its position.

 

[westward10]

I’m just on about when I need to switch my switches as lighting circuit is only on L1

If you are doing a global reading the three phases should be linked together.