Testing question

[keh7486]

Hi I'm about to start my testing course and started looking though my GN3 and I've got a question one of you lads could answer for me.
when doing insulation resistance test it states that all neon, dimmers, lamps and other sensitive equipment should be removed.
My question is do you remove all electrical items from the circuit, either by isolating or unplugging.
If so what would you do if you couldn't remove one, say there was a tv mounted to the wall and you couldnt get to the socket behind.
thanks in advance

 

[telectrix]

in that case you would not IR test L-N unless youy have funds to purchase a 42" LCD TV after you've fried it.

 

[moose]

Agree ^ then on a sheet you can im assuming write LIM in the sheet with a note to why..

 

[Plonker 3]

Agree ^ then on a sheet you can im assuming write LIM in the sheet with a note to why..

You would write that up in the section for agreed limitiation on the EICR sheet.

 

[ifindoubtdont]

Discussion time or Tin Hat...... OSG Page 10 612.3.2 . Where SPD's or other equipment (lah lah lah) or may suffer damage. Not practical to disconnect, test at 250V dc and at least 1Mohm. I personally start at 250 to see what's there. (Just in case).

 

[plugsandsparks]

Code it up as you cannot get access to a point of isolation and dont IR it.
In practice you are going to have to get used to stuff spoiling a good IR test.
Great for newly installed ccts but troublesome on well established lighting and socket ccts. I always use 250V setting for stuff i have not installed and on final ccts that are not simply point to point, this will do for 99% of the time but please dont mention it in an exam... lol

actually just had a look at the OSG to see if it allows reduced voltage testing and it is a recommendation as mentined above. There is also the option to tie LN together but TBH i really dont like the idea of LN tied and 500V, maybe my in-experience showing but i like 250V setting and i haven't blown anything up yet.

 

[RmBo_0]

When you think you've unplugged everything and your still getting a low reading and then find the Ariel booster tucked away in the loft somewhere. Happy days!