insulation res testing?

[brs73]

what methods do people use for testing insulation resistance on lighting circuits,when there are loads of transformers on the circuit?

 

[kung]

Hi brs73
Isolate tranny or drop to 250v dc IR test.
Regards
Kung.

 

[Mr Mark Sparks]

i would test l-e and n-e, l-n would be a limitation these should be agreed in advance with client if poss

 

[Archie]

Agreed, I always put down that Ins Res..' between L & N on lighting circuits as a limitation.
Even though you know that the readings will be OK, you'll alway get some Smart Alec saying 'did you disconnect all the fittings / remove all the lamps??'

 

[shafiq]

what is the acceptable insulation resistance of a lighting circuit

 

[Guest123]

Hey.

It depends what voltage you are testing at. Really you should be disconnecting all the transformers and other electronic equipment and testing at 500V - the minumum acceptable being 1Mohm but really should be greater than 200Mohm.

If you have to test at 250V, even though the minimum acceptable is 0.5Mohm, this would only be for a SELV circuit so really the minimum for this would be 1Mohm also but as I said really should be greater than 200Mohm.

Cheers

 

[Mr Mark Sparks]

the minimum reading on all 230/400v circuits is 1 meg ohm testing at 500v