Steinel spot one led problem

[ptarmigan]

Had a pir exterior spot that used a incandescent lamp but the unit started to flicker and then packed up so brought a steinel spot one with pir sensor to replace, before installing checked power and polarity to outside and fitted the steinel light which tripped the rcd for the ground floor lights, cooker and shower so checked that it was wired correctly again and same thing tripped the rcd, strange i thought so took the steinel down and temporarily wired a 60w incandescent lamp in and the lamp lights and no tripping.
Power for the light is taken from what used to be a lobby light but that was redundant since moving the front door outwards years ago and the old light worked without problems till it packed up, for testing i have a no contact buzzer/tester and a basic multimeter.

 

[EFLImpudence]

Many an hour is wasted on faulty new products.

Connect the lamp to a plug and see what happens on another circuit.

 

[ptarmigan]

It works so what does that mean?

 

[EFLImpudence]

Is there an RCD covering that circuit?

 

[ptarmigan]

Yes, they are both 63a/30Ma, the lights are split up and down with the sockets being on the upper one, all lights both up and down are led apart from 1 cfl on both circuits.

 

[EFLImpudence]

Recap.

New lamp trips RCD on the circuit to its proper position.
Ordinary lamp there does not trip RCD.

New lamp does not trip RCD on another circuit.

Don't really know what to suggest.

 

[ptarmigan]

Correct, But thinking about it the only other thing is a borrowed earth from the downstairs toilet to a light under the stairs a distance of 1m although both fittings are plastic and both lights are on the downstairs circuit as i checked when it tripped the second time yesterday after checking the light terminations.

 

[JohnW2]

Recap. New lamp trips RCD on the circuit to its proper position. ... Ordinary lamp there does not trip RCD.

The 'ordinary lamp' (60W incandescent) will presumably have been wired just L & N, hence could not (without 'scraping barrels') trip an RCD.

If the new lamp trips RCD 'on its proper circuit', it presumably must have L+N+E connections. Reversing the N & E connections would presumably result in an RCD trip? ... and ....

New lamp does not trip RCD on another circuit.

...maybe it's N and E were connected correctly for that test?

Kind Regards, John

 

[EFLImpudence]

The 'ordinary lamp' (60W incandescent) will presumably have been wired just L & N, hence could not (without 'scraping barrels') trip an RCD.

Ok - I suppose.

If the new lamp trips RCD 'on its proper circuit', it presumably must have L+N+E connections. Reversing the N & E connections would presumably result in an RCD trip? ... and ....
...maybe it's N and E were connected correctly for that test?

Well, 'scraping barrels' the OP said he checked polarity and rechecked it was wired correctly, so...


From what has been stated, the circuit and the new lamp would appear to be "alright" so - what does that leave?

 

[JohnW2]

Ok - I suppose. ..... Well, 'scraping barrels' the OP said he checked polarity and rechecked it was wired correctly, so...

Sure, but as you go on to imply, something 'must be wrong', despite what we've been told.

Kind Regards, John

 

[ptarmigan]

I know googling stuff can be a mistake but i found this although it relates to led strips.
Two things that immediately spring to mind. Firstly the LED light strip drivers probably have internal surge arrestors. When surge arrestors actually 'arrest' a surge it would be seen by the RCD as a fault current.

Secondly the RCD is supplying other circuits and the earth leakage it sees is the cumulative leakage of all those circuits simultaneously. Consequently if there's already a reasonably high amount of standing leakage on the other circuits even a small amount of extra leakage introduced by the LED drivers might be enough to take it past the tripping threshold.end quote.
Would it be worth me turning off the other 2 items on that half of the cu which are the shower and the cooker along with the washing machine which is plugged into the cooker socket and then seeing what happens or would they need to be disconnected in the cu.

 

[EFLImpudence]

Surely the surge-arrestor would be the same on both circuits - and why would there be a surge?

It is true that a small fault on the light circuit might cause an RCD to trip when a large load like a cooker or shower on another circuit is turned on, but not the other way round.
Were there such a fault on the cooker or shower circuit, then the RCD would trip when the cooker or shower were on.

 

[ptarmigan]

Going back to using an incandescent lamp and it working although as pointed out no earth was connected would it be worth trying a 9w bc led in without earth or would that work anyway as no imbalance could be detected without the earth.

 

[JohnW2]

Going back to using an incandescent lamp and it working although as pointed out no earth was connected would it be worth trying a 9w bc led in without earth or would that work anyway as no imbalance could be detected without the earth.

As I wrote, and as you suggest, if there is no 'earth' (deliberate or 'accidental'/unintentional) at the lamp, there is no way that it could result in an L-N imbalance that could trip an RCD.

Such an imbalance can only occur if some of the current in the L does not 'return' in the corresponding N but, rather, finds some route to earth.

Kind Regards, John

 

[ptarmigan]

Thanks John,
Im clutching at straws now.