Insulation resistance testing Lighting circuit

[Joseph Lewis]

Hi everyone. I'm looking for advise on how to test IR on commercial lighting. There's so many lights on 1 circuit , do I have to take out all the lamps in all the lights to perform the test or can I simply test between LN -E ?
Even though I have spent lots of time testing domestic installs and lots of installation work in commercial I lack experience testing it. And advice would be great

 

[westward10]

Disconnect neutral and just do L/E and N/E this is perfectly acceptable for an EICR. If you get any zero Meg readings it could be crossed neutrals. So if you get two or three zero readings disconnect all neutrals and retest, if you get okay readings it is crossed neutrals.

 

[Joseph Lewis]

Thanks for you reply.
So I just disconnect neutral from each light fitting ? Or at the board ? And its OK to do the test at 500v?

 

[Wilko]

I start at 250

 

[westward10]

Thanks for you reply.
So I just disconnect neutral from each light fitting ? Or at the board ? And its OK to do the test at 500v?

At the board, do it at 500V. Lighting rarely incorporates filters which trigger at 500V to give false readings. If the reading is down at 500 it will be down at 250. You could get all sorts of readings but anything above 2 Meg should be considered satisfactory. Don't forget my previous Post about crossed neutrals it is very common.

 

[westward10]

I should also say as a safety issue, if you cannot isolate the board, because it isn't always practical be careful disconnecting the neutrals in case they are not to terminal order. Pull one out and it is the wrong one can lead to arcing and if you are not overly experienced in testing can cause hazardous reactions, take care.

 

[Joseph Lewis]

96060"]Disconnect neutral and just do L/E and N/E this is perfectly acceptable for an EICR. If you get any zero Meg readings it could be crossed neutrals. So if you get two or three zero readings disconnect all neutrals and retest, if you get okay readings it is crossed neutrals.[/QUOTE]

I should also say as a safety issue, if you cannot isolate the board, because it isn't always practical be careful disconnecting the neutrals in case they are not to terminal order. Pull one out and it is the wrong one can lead to arcing and if you are not overly experienced in testing can cause hazardous reactions, take care.

Thanks for the advise , a great help . I will be very careful disconnecting the neutral

 

[Toneyz]

Hi everyone. I'm looking for advise on how to test IR on commercial lighting. There's so many lights on 1 circuit , do I have to take out all the lamps in all the lights to perform the test or can I simply test between LN -E ?
Even though I have spent lots of time testing domestic installs and lots of installation work in commercial I lack experience testing it. And advice would be great

Keep going at it the more you do the better it becomes to overcome these problems and you get to understand the unexpected reading you may get