Intemittent tripping RCD.

[PEG]

...Good advice,and don't start the CSI craic,until ALL standard tests have proved non-productive. I had an intermittent RCD trip,on a split way recently,no rhyme or reason,not for weeks,then won't reset,then fine...Narrowed to lighting circuit,which was both floors,a mix of old VIR in conduit,and new.It went from not resetting on a N-E fault,to a clear IR result,whilst i was jogging up and down the place. In the end,i left the MFT at the DB, IR locked,with threshold alarm set highish,and marched about some more...a tread centre of landing,upstairs,gets a beep!...carpet up,loose boards out,and there are two VIRs bent round the end of a section of displaced old conduit,which has come 20mm out from a Tee,the board slightly pressing on said item...Felt like i'd found the Golden Chalice...customer said "Oh".........so all worth it :icon12:

 

[andyelectric]

This may sound strange HHD but with no fault finding preconceptions you may have the benefit of not proceeding down 'well worn experience based' routes. More times than not this method will find a fault quickly. But frustratingly if the fault is not found quickly it can be a while to reconfigure yourself to start from scratch methodically which can waste time. I am speaking from an experience of fault finding on equipment systems here rather than fixed wiring installations but same principles in fault finding.

 

[polo1]

...Good advice,and don't start the CSI craic,until ALL standard tests have proved non-productive. I had an intermittent RCD trip,on a split way recently,no rhyme or reason,not for weeks,then won't reset,then fine...Narrowed to lighting circuit,which was both floors,a mix of old VIR in conduit,and new.It went from not resetting on a N-E fault,to a clear IR result,whilst i was jogging up and down the place. In the end,i left the MFT at the DB, IR locked,with threshold alarm set highish,and marched about some more...a tread centre of landing,upstairs,gets a beep!...carpet up,loose boards out,and there are two VIRs bent round the end of a section of displaced old conduit,which has come 20mm out from a Tee,the board slightly pressing on said item...Felt like i'd found the Golden Chalice...customer said "Oh".........so all worth it :icon12:

Which MFT were you using PEG?

 

[nickblake]

Id put it down to a thermal related neutral to earth fault where a screw has nipped the neutral so when that point it warms very slightly causing the RCD to trip ,could be anything great fun these faults to find

 

[Knobhead]

3 years on the forum and still asking about RCD faults?

There’s only one way to find a fault, go and test the damn thing!

People on here will guess or come up with “I had xxxx last week”, non of which will help.

 

[UNG]

Can't wait for the updates on this one!

I'd be asking about leaks, DIY, outdoor connections, ...........

.............How old is the fridge and freezer if they are on the tripping RCD

 

[uksparks]

I hate faults where its not clean cut as to what it is, i usually start by scratching my head thinking hmmm... I wonder where to start.

Its not too bad when its a nice modern house, but its when its an old cottage or something like that where it becomes a nightmare.

 

[polo1]

3 years on the forum and still asking about RCD faults?

There’s only one way to find a fault, go and test the damn thing!

People on here will guess or come up with “I had xxxx last week”, non of which will help.

Ah, the true GG! I can kinda see where you're coming from Tony. On the other hand, I find it good for guys to tell us about faults they have found and how....it all adds to my/our knowledge.
Now, If only PEG would tell us about the mft that lets him do the trick he described.....

 

[Octopus]

...Good advice,and don't start the CSI craic,until ALL standard tests have proved non-productive. I had an intermittent RCD trip,on a split way recently,no rhyme or reason,not for weeks,then won't reset,then fine...Narrowed to lighting circuit,which was both floors,a mix of old VIR in conduit,and new.It went from not resetting on a N-E fault,to a clear IR result,whilst i was jogging up and down the place. In the end,i left the MFT at the DB, IR locked,with threshold alarm set highish,and marched about some more...a tread centre of landing,upstairs,gets a beep!...carpet up,loose boards out,and there are two VIRs bent round the end of a section of displaced old conduit,which has come 20mm out from a Tee,the board slightly pressing on said item...Felt like i'd found the Golden Chalice...customer said "Oh".........so all worth it :icon12:

Which MFT is that?

 

[Plonker 3]

A quick google search brings this tester range up

http://www.megger.com/me/products/ProductDetails.php?ID=612

 

[driverman]

Could be all those nice Christmasy items plugged in all over the place, internal as well as external. Have fun.

 

[HappyHippyDad]

Got there at 8am, found the fault by 9am, home with a cup of tea for 9.30am :smile5:

Actually I was a bit disappointed, I was prepared for battle and It wasn't even a minor skirmish!

Global IR test on faulty side showed 0.000MΩ, Only 3 circuits, so quickly broken down to discover fault was on the kitchen ring.

The house was pretty much a building site and was a complete DIY wiring job which the chap was quite happy to admit. He had a plug in one of the sockets which went into a cupboard and then fed another double socket on the side of the cupboard. This was the faulty set up and as soon as I unplugged it the fault cleared! Still feels good though finding it...

3 years on the forum and still asking about RCD faults?

There’s only one way to find a fault, go and test the damn thing!

People on here will guess or come up with “I had xxxx last week”, non of which will help.

Good Morning to you as well Tony, hope you have a happy day you cheery fellow :smile5:

 

[HappyHippyDad]

Post removed as I felt guilty!

 

[telectrix]

hope you charged him well. bloody DIY plonker.

 

[HandySparks]

Removed as I felt guilty!

Drat! I should have done a 'reply with quote' while I had the chance.

I was going to ask whether you'd had a glass too many with your lunch.

 

[Jay Sparks]

The first thing I do with a fault is forget everything the customer tells you!!!lol

No DIY work my Ar3e!!

Jay

 

[HappyHippyDad]

Drat! I should have done a 'reply with quote' while I had the chance.

I was going to ask whether you'd had a glass too many with your lunch.

Ha Ha, I wondered if anyone saw it! I was tempted to leave it but thought better of it!

 

[telectrix]

you're allowed to say "arse". it's in the oxford english dictionary.

 

[HappyHippyDad]

The first thing I do with a fault is forget everything the customer tells you!!!lol

No DIY work my Ar3e!!

Jay

It was actually his wife that had said 'no recent work'. He was happy to explain everything he had done recently... which included the extractor fan, 2 spurs and the 'faulty plug/socket'. The only good point was that he could tell me the exact layout of the ring in the kitchen!!

 

[Jay Sparks]

you're allowed to say "arse". it's in the oxford english dictionary.

Its my anarexia....I sometines mis pel thins.