smokes keep tripping

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meady

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Hi fellas, hope you are all enjoying your weekend

Did yet another cu upgrade today, big old house with multiple extensions over the years. Pretty much all the circuits were rings including all 4 light circuits. I installed a splitt load board with 3 socket rings, cooker, and utility room sockets on rcd side and put 5 rcbo in for the lights and smoke circuit. Anyway the smoke circuit kept tripping everytime I powered up

We checked all connections especially the neautrals in the consumer unit and the smoke detectors and all seemed fine.

By this time I had run out of light and the owners were going out so I said I will come back tomorrow to find the problem. Any ideas?

I will be testing tomorrow so no results to give.

 
would it be worth trying the live from the smoke and put it into same rcbo as the lights (one by one) and see if it trips.wonder if there wired in to a light circuit.

 
Hi meady,

you will be an expert at changing cu's if you carry on like this!

I would take the live, netrul and earth of the smoke circuit and put them in to a mcb. like adrian said you may have a N in the wrong place. did you do a IR test and r1 r2? it may have been wrong for years on an old fuse board.

sounds like you will be working a sunday

good luck

paul

 
Hi meady,you will be an expert at changing cu's if you carry on like this!

I would take the live, netrul and earth of the smoke circuit and put them in to a mcb. like adrian said you may have a N in the wrong place. did you do a IR test and r1 r2? it may have been wrong for years on an old fuse board.

sounds like you will be working a sunday

good luck

paul
Alright fella....hope all is well

I Am testing the circuit tomorrow cos the owners wanted me out. I tested all the other circuits and they were fine apart from a couple of low ir readings but they were passable.

Been racking my brains about this on the drive home, if it's a borrowed neutral from the lights surely the lights would trip aswell? Or would they? Hhmmmm.

Poxy cu changes lol

got another next Saturday ; -)......I should have the letters cu after my name ha ha

 
I would suspect a crossover on the neutral, if two circuits share a neutral and are on seperate rcd protection they will trip every time.

If the nutral is on the opposing rcd it will trip.

Disconnect the smokes and test whilst not connected to see if you have any continuity across any of the cables and the neutral bars on the cu.

This would show up any shared neutrals.

 
I would suspect a crossover on the neutral, if two circuits share a neutral and are on seperate rcd protection they will trip every time.If the nutral is on the opposing rcd it will trip.

Disconnect the smokes and test whilst not connected to see if you have any continuity across any of the cables and the neutral bars on the cu.

This would show up any shared neutrals.
Did that first thing and "bobs your uncle".......found the shared neutral. All sorted and owners are pleased thank god.

 
Another next week!just out of curiosity how much are you charging for them?
It depends on the layout, convienience of services and accessability of the cu, pain in the a**e when they are tucked under stairs or some little cubby hole. On average I would charge around

 
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