Lighting Circuit r1+r2 values.

[CDB]

Are you registering voltage between line/earth at the light fitting and is the insulation resistance clear.

Obviously this is a dead test so if you are asking about 230v I have not looked.

But could I be picking up on Smoke/Heat alarms or Emergency Lighting?

But if that is the case then why are the other lights not seeing the same issue. Argh - my computer scientist brain likes consistency!

Thanks for the continued help by the way!

 

[westward10]

It isn't a problem I thought you meant ohms for when the switch was open. I assume you get 130 meg ohm when you IR test the whole circuit with all switches closed.

 

[CDB]

It isn't a problem I thought you meant ohms for when the switch was open. I assume you get 130 meg ohm when you IR test the whole circuit with all switches closed.

Yes 130 meg ohm for IR.

But either 130 or 150 ohm for the two problem pendants when switch is closed.

 

[westward10]

It is not a problem 130 meg ohm is well above what you require. Your picture indicates the wiring to be 50 odd years old and you would not necessarily expect an infinite IR reading especially on a lighting circuit, I would think no more of it.

 

[CDB]

It's not the IR that concerns me because as you put it the wiring is old and it's well above the minimum.

My question relates to the 130 OHM and 150 OHM I'm getting for the R1+R2 test on two different pendants when the switch is open. If the switch is open I should be getting open circuit or in my case >2000 ohm as I do with all the other lights on that circuit.

 

[Ian1981]

Are the switches relatively old as you could be getting dirt on the contacts at the switch tracking across or you may have leakage through lower insulation resistance

 

[westward10]

It is possible old, worn switches are the cause but I wouldn't have thought low ohms would pick this up but yes ditch the wiring from the switch.

 

[Ian1981]

Disconnect at switches and see what you get

 

[CDB]

Are the switches relatively old as you could be getting dirt on the contacts at the switch tracking across or you may have leakage through lower insulation resistance

Hi Ian,

Dodgy switches was my first thought. They are old.

To determine your second suggestion I guess I would need to do a full IR which is pretty difficult given the installation.

Switches first!

Thanks for the ideas.

 

[Deleted member 26818]

Are the CPCs for these pendants connected in terminals, or twisted together either at the roses or perhaps in JBs in the loft?

 

[westward10]

Hi Ian,

Dodgy switches was my first thought. They are old.

To determine your second suggestion I guess I would need to do a full IR which is pretty difficult given the installation.

Switches first!

Thanks for the ideas.

Why is it difficult to do a full IR you can ignore the L/N test.