low insulation resistance reading

[jpaul]

Hi,

So I did and insulation resistance test on a lighting circuit today.

L-N 0.23
L-E 34.9
N-E 35.8

The L-N is under the required reading, what do I do?
Do I turn it off completely or advice the customer to get it re wired and leave it on???? Cheers

 

[Tiny Spark]

Sure you are not getting a short from a lamp or something daft like that?

If not then you need to find the part of the cct with the problem.
Split the cct down and test parts until you find the issue.

 

[Bobster]

Are you sure there isn't a dimmer in the circuit?

You can't make a customer switch a circuit off only recommend. I doubt all of it needs a re wire, any outside lights on this circuit?

Is this something you've installed? Or just an eicr?

 

[jpaul]

definatley not a lamp, old ali cable joined up to new copper = pain in the butt

 

[Richard Burns]

0.23Mohm sounds like a modern neon or a dimmer switch in circuit.

 

[markythesparky]

Might not be a lamp. Shaver socket? Transformer? Dimmer? LED? Could be lots of things. Half split the circuit and try again.

 

[jpaul]

no dimmers, there are outside lights but lamps out. I haven't installed anything - the lamps keep blowing so was testing to try and solve a problem.

- - - Updated - - -

theres no neons or dimmers in the circuit

 

[not clever]

TV splitter in the loft
Neon on loft light switch

 

[ferg]

yay another wind up, haven't seen one of those for a while.

 

[jpaul]

no neons or tv splitters, down stairs lighting circuit

 

[Marvo]

Daylight sensor/pir motion sensor switch maybe? I wouldn't advise on a re-wire or any other remedial action until you know exactly where the fault is, you may end up with egg on your face.

 

[Richard Burns]

PIR sensors on outside lamps?


As has just been said!

 

[jpaul]

disconnected the pir, still the same reading. What about it's just old wiring and degrading

 

[markythesparky]

What about half splitting the circuit and doing the test again?

 

[Tiny Spark]

Break down the cct and test individual cables to find the fault.

 

[Silly Sausage]

definatley not a lamp, old ali cable joined up to new copper = pain in the butt

That'll be the tinned copper per chance?!

 

[Marvo]

Break down the cct and test individual cables to find the fault.

Agreed, you ought to localise it to a specific cable. I've got a tenner that says it will be something else causing it though.

 

[Guitarist]

Hi,

So I did and insulation resistance test on a lighting circuit today.

L-N 0.23
L-E 34.9
N-E 35.8

The L-N is under the required reading, what do I do?
Do I turn it off completely or advice the customer to get it re wired and leave it on???? Cheers

Are you actually an electrician? You can't ask a forum whether a rewire is required!

 

[DNS1]

Jpaul, are your test results in ohms or Mohms?!

What test voltage is being used?

On a lighting circuit I'd be looking at the usual culprits first. PIR, dimmer, extractor fan, shaver socket etc

 

[ipf]

That'll be the tinned copper per chance?!

Fair chance, I'd say.