strange fault

[wattsup]

Strange fault.
Rewire, 8 circuits all rcbo protected
Tests out ok
Intermittent fault
Turn basement lights off at switch (fed via a 6a rcbo)

basement power trips? (on an adjacent 16a rcbo)
no crossed neutrals.

The 16a rcbo trips when turning lights off not on?
Any ideas, never seen this type of fault before.

Impossible ? you would think, or i would

 

[vernam616]

Im intrigued now, please update the thread when you find out!

 

[BigBreakfast]

so that could be something similar to an induced voltage affecting adjacent RCBO? clutching at an ethereal straw here! LOL.

Well that was one of my thoughts too, in the end I think I swapped out a couple of rcbos and the problem never appeared again?

 

[telectrix]

nothing wrong with proteus boards... in a skip.

 

[tony mc]

If your lighting cct is not tripping when you switch off the basement lights and only the 16 A RCBO trips out my money is on that one being faulty in some internal way IMO.

Have you tried replacing the 16A one for another to see if the problem replicates its self.

As you have stated the RCBO should be electronically OK but with lots of things these days you are now the quality control person but don't get paid for it.

Hope you get to the bottom of it!!

 

[OldeSparky]

earth neutral fault on other circuit...

 

[Blowcat]

Any wireless / UHF equipment near the DB.
I've had a whole DB full of RCBO's trip out due to a radio transmitter by the DB.

 

[kung]

Be intresting on discon flyleads !
good luck buddy when you do find the fault please post on my Tell us your faults thread.
Regards
Kung.

 

[wattsup]

Update
First off, it is a protek board / rcbo's, not proteus as I first said. Don't know why I said proteus
Anyhow, tried the easy bits first, no loose neutrals etc
Disconnected rcbo earth tails, still trips basement power.
Last resort, which I knew would be pain, move rcbo basement 16a rcbo to far end of board
At first I thought fixed, no trip, went into overdrive on off on off basement lights, tried it 20 times or more, customer at side of me, no trip.
Right fixed!
Err no, packed tools up, turned basement lights off, friggin downstairs ring main tripped.
The actual basement lights never trip, always other rcbo.
As I said before, the basement lighting circuit is 3 fluros and one pir flood only, I can actually physically see and trace cables, no damage, all connections secure blah de blah..
Please remember, trip only happen when switching off lights, not on.
Headache, I'm going to fit a new board, Crabtree Wylex or MEM I asked the customer to get, (I didn't supply anything) see what happens...
Lost me this one

 

[vernam616]

how are the flouros wired? i presume 3 plate then a loop off to others? try disconnecting the loop to rule out dodgy fittings etc..

But going back to my fault previous the loose neutrals in the flourescent fitting caused other rcbo's to trip whenever i turned the light OFF,

 

[tony mc]

Thanks for the update!

Out of interest what make were the RCBO's.

 

[vernam616]

Thanks for the update!

Out of interest what make were the RCBO's.

He quoted above the make was "Protek"

 

[pjcomp]

In case it is induced by the neighbouring MCB, have you got space to put a blank between them? Or move them around the board? Just to test out the theory, be interesting to hear if it cures it.

PJ

 

[wattsup]

Its the switching off, that causes the trip. No, not three plate, neutrals connected thru at switch boxes.

I can't get my head round to the 'off' that causes other rcbo to trip. If rcd then maybe dodgy ne fault, but not rcbo's. Each rcbo should be a dedicated circuit?

 

[vernam616]

well change the first light for a normal pendant and see what happens?

 

[OldeSparky]

please check you you dont have a neutral earth fault..

it doesnt have to be on the same circuit...

put money on it