How to IR test a lighting circuit

[slippyr4]

Lighting circuit consisting of 3 fluorescent tubes. What is the proper way to IR test it?

Is it, disconnect P,N,E from the light fittings, and all switches on, then test from CU end?

or some other method?

 

[Spark123]

What type of fluorescent fittings are they, are they electronic ballasts?

 

[slippyr4]

They're entirely standard from B&Q units. They have the chunky heavy ballasts, as opposed to a circuit board. I think they're called reactive ballasts. Is that what you mean?

 

[Spark123]

I take it you have checked the earth continuity 1st?
Take the tubes out, disconnect the PF capacitors and with all the light switches on, IR test the CU end. L-N, L-E, N-E.

 

[slippyr4]

Yep, done my R1+R2's already. Was just wondering if fluorescent fittings needed disconnecting or not, as an incandescent bulb would.

thanks for the help

 

[slippyr4]

Should I be expecting my (newly acquired) megger to be reading approximately infinity when doing these tests?

It's an AVO Megger BM100/4 (which is an analogue one).

I'll check it by testing it with a known resistance tomorrow. But is brand new conduit wiring typically more than 200 M ohm?

 

[Spark123]

Yup, the more the merrier
(you're using 500v setting I take it?)

 

[RF Lighting]

Most brand new wiring should read infinity, singles in conduit included.

 

[dingbat]

Make sure you're not just measuring the insulation resistance of fresh air!
Don't enter 'infinity' on your test sheet - record what your meter actually displays.

 

[slippyr4]

Yep, am using 500V - it's all it does - the BM100/4 is a rather basic meter it seems. But it'll do cos my house has no SELV, so everything is to be tested at 500V.

I did test the last remaining old rubber circuit in the house, and that came out at about 40 megohm, so it probably is working. will test later with a resistor pack.

thanks for the help guys.