Testing insulation resistance

[learningspark]

Could anyone explain this test from start to finish? I.e .....lamp removal......fuse spares, ring final etc? Also do you do the tails?

 

[Electricalserv]

If I was on my comp I'd write it out for you, but I'm not. No you don't do tails

 

[SirKit Breaker]

Lighting. Disconnect circuit from CU, remove dimmer switches and join the line and switch line together, either remove all lamps and IR L-E, L-N, and N-E, or leave lamps in and join L and N together and test L and N to E. Ensure all switches are on prior to test, and repeat tests with 2 way switches in opposite directions to make sure you test the full circuit.

Rings and radials, disconnect both ends for ring, or the one end for a radial from the cu, make sure everything is unplugged and all FCU's are OFF. Test L-E. L-N, N-E.

Your best bet is to get GN3 it is all explained in detail and step by step.

Cheers........Howard

 

[mickys86]

You'll find a step by step guide in the on site guide. Do you have one?

 

[learningspark]

Sir kit , thankyou very much

Mickey I do but problem
Is as you would see with my tail comment.....I ask people and get alsorts of different answers, I don't see it in regs and wonder.

 

[NMc]

Check out guidance note 3 page 37

 

[SPARTYKUS]

Hi

good question about tails - reason that springs to mind as to why you would not do them is it would require entering the meter which is a no-no.

 

[learningspark]

There are a few vids on YouTube I have been watching were they do test the tails, what is that for?

 

[Electricalserv]

Ze external impedence

 

[BOROROBBO]

There are a few vids on YouTube I have been watching were they do test the tails, what is that for?

might be testing the tails to make sure theyre not damaged which could blow the 60/80/100 amp fuse and its expensive to get the electricity board out to fit new fuse.

i got told to do the same thing on a job i was on for that very reason

cheers

 

[Electricalserv]

Post the videos I'm 99.9% sure it will be ze

 

[SirKit Breaker]

You do an IR test of the full installation at the tails on a test rig as part of the 2391 course.

Cheers.........Howard

 

[Electricalserv]

Yes but there is nowhere on an eic which asks for an IR on the tails. The 2391 exam on tails is to IR on the whole installation. If I remember rightly it was the fault finding exam.

 

[Steve 82]

Another easier, acceptable method is to insulation resistance test the whole installation at once. By testing between the output side of the main db isolator. line to neutral, line to earth, neutral to earth. This will test the whole installation, and as long as you have adequate readings, you wouldn't need to start doing each circuit individually.

 

[Electricalserv]

Good point stevo