Insulation resistance test with transformers.

[panny300]

i understand tha an insulation resistance test uses 500v,and the usual advice is to disconnect electronic equipment and led warning lights on switches.it seems there is a lot of people fitting 12v downlights.i know someone who has about 40 spread through the house,so if a spark was testing,would all of the transformers have to be disconnected?

 

[Taylortwocities]

Yes
IR test circuits then connect the trannys afterwards

 

[securespark]

It is acceptable according to the ECA to do Method 2 IR test, ie link N & L & test across them to earth.

 

[GaryMo]

It is acceptable according to the ECA to do Method 2 IR test, ie link N & L & test across them to earth.

Yes, when doing a periodic inspection report which I guess is what the OP is talking about.

If not then this method can't be used for initial verification of a new circuit.

 

[Adam_151]

If not then this method can't be used for initial verification of a new circuit.

Which is easy enough, you just do the IR before installing the transformers

 

[Taylortwocities]

IR test circuits then connect the trannys afterwards

I wish I had thought of that....

 

[panny300]

thanks everyone,yes i did mean if they were already installed.

 

[GaryMo]

If not then this method can't be used for initial verification of a new circuit.

Which is easy enough, you just do the IR before installing the transformers

I'm well aware of that!

 

[Taylortwocities]

thanks everyone,yes i did mean if they were already installed.

Then you cant do an insulation test as the transformers will be hanging between L & N. If you try you'll scrog the trannies.

 

[panny300]

just reading post again and spotted another question,if garymo is correct and you put live and neutral together and test between those and earth,then you havn't tested between live and neutral.
I thought all 3 had to be tested between each other to pass.
as i mentioned i know someone with about 40 Lv downlighters,so lets say they added a few more to the lighting circuit in another room.as i understand it the whole of the circuit would have to be tested,(is that correct).
according to taylortwocities it would blow the trannies if testing between live/neutral.
so was wondering what sparks would do faced with adding lets say 5 lights,then having to take all of the bulbs and transformers out of the rest of the circuit to do their tests.
How many of you would bother with the test?

 

[Adam_151]

I'm well aware of that!