IR testing

[Sb8389]

Hi guys,
might make myself look stupid here
when wanting to carry out an IR test on a lighting circuit and you have sensitive equipment that you can't disconnect,if you do an IR test linking L-N to Earth is this basically the same as testing L-N.
the reason I'm asking is because I have an issue on a job where a customer is saying they are having an issue with there lights randomly tripping the MCB. I have already IR tested L-E and N-E and both came in at around 3.6meg, so I'm just curious if it's worth doing an L-N test and disconnect all loads

thanks for any replies

 

[uksparks]

Testing LN-E just makes it so there's no imbalance between L and N so it shouldn't cause any damage, however if you have tripping I'd disconnect all loads and blast it with a trillion vaults

 

[davesparks]

If it's randomly tripping what makes you think it ls a L-N IR issue?
Have you looked at the type of lights connected to the circuit and fully discussed the symptoms with the customer?

 

[Simonslimline]

Hi guys,
might make myself look stupid here 
when wanting to carry out an IR test on a lighting circuit and you have sensitive equipment that you can't disconnect,if you do an IR test linking L-N to Earth is this basically the same as testing L-N.
the reason I'm asking is because I have an issue on a job where a customer is saying they are having an issue with there lights randomly tripping the MCB. I have already IR tested L-E and N-E and both came in at around 3.6meg, so I'm just curious if it's worth doing an L-N test and disconnect all loads

thanks for any replies

No, it is testing between the live conductors & earth.

Testing between line & Neutral is testing between the live conductors.

 

[telectrix]

if it's the MCB that's tripping, then it's either

1. intermittent short circuit

2. " " overload

3. lamps blowing and taking the MCB out due to surge current.

 

[Pete999]

Hi guys,
might make myself look stupid here 
when wanting to carry out an IR test on a lighting circuit and you have sensitive equipment that you can't disconnect,if you do an IR test linking L-N to Earth is this basically the same as testing L-N.
the reason I'm asking is because I have an issue on a job where a customer is saying they are having an issue with there lights randomly tripping the MCB. I have already IR tested L-E and N-E and both came in at around 3.6meg, so I'm just curious if it's worth doing an L-N test and disconnect all loads

thanks for any replies

What make you think it is an IR problem? if it was me I would check the current being drawn on the particular circuit in question, it could be that the circuit is working on the limit of the OCPD and trips randomly when someone say, swotches an extra light on, try it and see, you might be lucky.

 

[varilite]

put in a bigger breaker that should do it