First time in years could not find fault

[chris day]

split load DB

Every circuit (7circuits) 1st half tripped RCCD

And two circuits second side tripped The 1st RCCD whist the second RCCD supplying these circuits remained on??

Swapped over the RCCDs to prove the units were not faulty.

Removed every neutral to prove borrowed neutral not at fault still tripped.

Any suggestions guys as I am the second sparky with a damaged ego on this one

 

[Deleted member 9648]

N-E fault somewhere. Did you IR test?

 

[SparkyChick]

When you say you removed every neutral... did you take them out one at a time or all together?

Could be you're chasing multiple faults

 

[Octopus]

Are the incoming tails tight in the DNO head and / or meter - seen this on a number of occassions.

And yes - it woud trip 1 or both RCD's ...

Have you got a clamp meter - this may give you some pointers ...

 

[lurch]

. . .. . agree with above. Dead tests first. IR tests.. then test between circuits . . .

 

[PEG]

split load DB

Every circuit (7circuits) 1st half tripped RCCD

And two circuits second side tripped The 1st RCCD whist the second RCCD supplying these circuits remained on??

Swapped over the RCCDs to prove the units were not faulty.

Removed every neutral to prove borrowed neutral not at fault still tripped.

Any suggestions guys as I am the second sparky with a damaged ego on this one

Hi bud,not crabbing your methodology,but i would have isolated and tested the two RCD's independently,before guessing at not swapping two faulty units.

No matter who,and how many,have has looked at this problem,you need to start right at the beginning,and use the known and trusted methods,one step at a time.

These will not 100% guarantee a result,but it massively limits,what else can be happening.

As for guessing what is going on,aside from what is obvious,a whole host of additional information would be required,up to including,a practical joking teenager,next door,with a home-made EMP device,made from a you-tube instructional.....don't ask...

 

[dmxtothemax]

I think Sparkychick hit the nail on the head !
Multiple faults !
This would explain why no one can find the problem.
All the testing so far is based around the theory that there is one fault !
When there could be several.
Consider the possibility of several faults !
don't forget to come back and tell us what it was ?

 

[chris day]

Ok very embarrassed as client called another electrician round as I had been busy on an install.
They unplugged the one thing I thought would be fine as it was brand new and fixed in.
Bigger question how does one faulty washer dryer prevent the entires 1st split set of MCBs from switching on the RCCD.
EGO has been hurt a little as some glory hogger stole the spot light, just like the Americans in WW2. Haha

 

[Octopus]

How can you do proper fault finding of a scoket circuit with items still plugged in? I don't think you can!

I would say there is still a fault to be found ..............

 

[ruston]

Yes , like @SparkyChick alluded to earlier.
Probably cumlative leakage if one item cleared it .
Or you may have been had by the solution.

 

[chris day]

Yes , like @SparkyChick alluded to earlier.
Probably cumlative leakage if one item cleared it .
Ow i see what your saying, one large fault placed the RCCD over the thershold with all the remaining minute leakages still exeisting.

 

[Deleted member 9648]

How can you do proper fault finding of a scoket circuit with items still plugged in? I don't think you can!

I would say there is still a fault to be found ..............

How can you do proper fault finding of a scoket circuit with items still plugged in? I don't think you can!

I would say there is still

I do. Every RCD tripping fault I come across I want every possible source of the fault left in place when I initially test. Only if L-N tests are being conducted would connected loads need to be isolated.

 

[kingeri]

Before I started scratching my head I would have unplugged EVERYTHING!!

 

[richy3333]

Sounds like a 2 pipe riddle to me

 

[DPG]

Sounds like a 2 pipe riddle to me

Sounds rude to me