Insulation resistance test

ian.goddard57 · May 12, 2012

Anyone who knows. Lighting circuit with MAINS voltage LED downlighters. If I do a 500v Insulation Resistance test on LED bulbs. Will it knock out the bulbs.
I know its electronic equipment that gets destroyed predominently.
Its quite a few down lighters, didn't want to hit the button without checking. Costly mistake.

Strima · May 12, 2012

Never tried it and never will. Pound to a pinch of poo it will fry the LED's, or they'll glow very brightly.

ebow72 · May 12, 2012

can you not do it on a 250v test? Your results will obviously be halved.
There is another way, but I don't want to tell you just yet in case you might not be sure of what to do, why are you wanting to do a IR test do you mind me asking??

Silly Sausage · May 12, 2012

ian.goddard57 said:
Anyone who knows. Lighting circuit with MAINS voltage LED downlighters. If I do a 500v Insulation Resistance test on LED bulbs. Will it knock out the bulbs.
I know its electronic equipment that gets destroyed predominently.
Its quite a few down lighters, didn't want to hit the button without checking. Costly mistake.

When you're doing a (Periodic) inspection, all you need to do is IR between L&N to Earth.
If in doubt, start with 250V.

ebow72 · May 12, 2012

Archy Styrigg said:
When you're doing a (Periodic) inspection, all you need to do is IR between L&N to Earth.
If in doubt, start with 250V.

I was going to suggest that, but didn't want to just in case he decided to do it now...

Silly Sausage · May 12, 2012

ebow72 said:
... case he decided to do it now...

I hope not, unless he's in Australia.
It's getting a bit dark here now.

ian.goddard57 · May 12, 2012

Hi Ebow,

Thanks for your advice. Think that might well be the safe option on this circuit.

first lighting circuit install as part of dare I say it PART P. Doing the testing ready for building control electrical testers to check my work before I can join a registering body.
Plumber by trade. Did the Part P so I can use it during the course of my work. I know fully qualified proper electritions dont like this much but it assists me to be more versatile in these difficult times.

Ian

jdd · May 12, 2012

I'd never take the risk, as previously posted L&N - E will be sufficient, or limitation on periodic. I'm assuming it's not an install cert for obvious reasons.

ian.goddard57 · May 12, 2012

Thanks very much to you all.

I'll go for the softer 250v insulation test.

Cheers

Ian

habitual · May 12, 2012

ian.goddard57 said:
Hi Ebow,

Thanks for your advice. Think that might well be the safe option on this circuit.

first lighting circuit install as part of dare I say it PART P. Doing the testing ready for building control electrical testers to check my work before I can join a registering body.
Plumber by trade. Did the Part P so I can use it during the course of my work. I know fully qualified proper electritions dont like this much but it assists me to be more versatile in these difficult times.

Ian

I am sorry but others may have missed this post. If this is a new install then all the dead tests should be performed before any circuit is energised, all the lamps should be removed and the insulation tests carried out properly. The correct procedure would be to test each cable against each other freely, then connect the earth to the MET and test against earth, this will establish any faults in the cable during installation.
If it is a periodic then the described methods above will suffice, never test at full d.c. voltage until you are sure. It saves you some embarrassment.