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

 

[wattsup]

no ne fault, my first thought btw. In any case if ne fault it would/should trip the relevant rcbo...I would think? and the fault would be there whatever ...only trips when switch off basement lights.

 

[ChristianG]

Make sure that if the l/n terminals have a resistor across them that all the fittings that supposed to have them do have them.

We had a fitting that was doing the exact same thing, it was missing its resistor that it normally had. Replaced that and the rcd didn't trip anymore.

 

[wattsup]

Make sure that if the l/n terminals have a resistor across them

Ahh, I do know one fitting has the supressor for sure.....I'll check the others on monday, good call, hope you are right,,,clutching at anything right now

 

[OldeSparky]

no ne fault, my first thought btw. In any case if ne fault it would/should trip the relevant rcbo...I would think? and the fault would be there whatever ...only trips when switch off basement lights.

no it wont i have been there.. check again

 

[ackbarthestar]

I'd agree with des56. and OldeSparky
unbalanced Neutral earth voltages, however they are caused, can produce nuisance tripping on other unrelated RCBOs. Its usually caused at the point of switching both on and off.

 

[Blowcat]

Do you have any items plugged into the 16amp circuit that trips out? if so what are they.

Its really is a brain teaser this one..., Have you done a full IR test? Might be worth doing it again
Are you sure you got L&N connected correctly in the fittings including PIR?
Check you have the same L&N out the RCD for all ccts?
Is the neutral bar correcly connected.

Any chance of getting a pic so we can all have a look of the DB?

 

[wattsup]

Tested again, same 'good results'...so changed board to wylex. Problem fixed!

Another ...kin 6 hours testing retesting, scratching head, but some relief at last...beware of protek rcbos

 

[richy3333]

I've been following the thread with interest. Glad to hear it's been resolved, mate. The old adage of buy cheap, pay twice comes to mind. It's just a shame the customer cant ever see this!

 

[Big n Daft]

The Great Lord Proteus strikes again.
Complete and utter CEF rubbish, another example of whats wrong with the bloody industry. How on earth are these companies in business peddling such rubbish.

 

[ChristianG]

Proteus? Oh dear, looks like a few fuseboard changes for some social housing in a few years then.

 

[OldeSparky]

do what i did last month, send them a bill..

i got £150.00 off JCC for some crappy fittings of theirs i tried to fit and were faulty..

 

[Blowcat]

Tested again, same 'good results'...so changed board to wylex. Problem fixed!

Another ...kin 6 hours testing retesting, scratching head, but some relief at last...beware of protek rcbos

Thanks for the update, been thinking bout this fault lots, thank god its fixed

 

[wattsup]

just come to light tonight...
A year or so ago there was a 'bad batch' of protec rcd's/rcbo's.
Anyhow the manager of the wholesaler (small independant shop) vowed never to stock protec ever again, sick of callouts and exchanging cu's for contractors who had bought.

The supplier gave assurances the problem was fixed, so he bought in again at a very cheap price...sweetener. All has been well apparently for the past 12 months or so. Until now!