RCCB Tripping

[adam1984]

Afternoon all.

This is a weird one but I thought i would ask your thoughts to satisfy my own cuisosity and apologies for long post!

Board is a Crabtree with 1no RCCB. The RCCB tripped when the TV was plugged in and socket turned on. RCCB would not instantly re-set but it did after a couple of minute.

The RCCB supplied: Downstairs power, Upstairs Power, kitchen, Extension, utility/boiler (5mcbs)

So I reset RCCB. Go back to "TV Socket", plug in Martindale socket tester, switch on socket switch and RCCB trips (do this a couple more times and keeps tripping) The TV socket is on Downstairs power MCB.

Homewoner says that its normally the tumble dryer / kettle / microwave (on the utility MCB) that ususally trips the RCCB but once reset they work again.

Reset RCCB and and all MCB's are in the ON position. Go to utility room and plug Martindale socket tester into socket, switch on and RCCB trips again. I try several different sockets and trips every time however when the boiler is fired up it doe not trip the RCCB.

If I turn off the MCB to the Utility room and try my Martindale socket tester in the kitchen sockets then it trips the RCCB. If i turn off the the Extension and utility / boiler MCB then the "TV Socket" does not trip the RCCB and nieither do the kitchen sockets.

Now the extension is actually a 2 storey extension but when I turn this MCB off it only turns the power off to the downstair extension (granted the upstairs may have been taken off the upstairs power)

I took off every socket face on the affected circuits and wiring all looked fine. I checked all cables where possible (ones clipped direct etc) for signs of damage. I asked the homewoner if they have done any DIY recently. I checked all outside equipment for signs of water ingress or damage and everything I checked looked ok and no signs of damage.

The homeowner has lived in the house for approx 4 years and on the face of it it is really modern and had a massive refurb job done by the previous owners but the current homeowner has said they have had quite a lot of problems with te house and especially with the electrics.

I think that there is a dodgy conection somewhere but I couldnt find it so must be burried in / behind a wall somewhere.The junction boxes I found were wired ok. Anyone shed some light on what they think it may be? Ways in which you would try and trace fault? No insulation resistance test was carried out.

 

[telectrix]

IR test. ramp test ( both with circuits connected and not connected ). earth leakage clamp meter round the tails. before that's done we're guessing.

 

[urbanmonkey]

Sounds like its time to get the proper test gear out and go through the usuals, should pick it up fairly quickly!

Probably throw the martindale socket tester in the bin as well.

 

[polo1]

Back to basics! Get the insulation res testing done, circuit by circuit. You need to break down the installation into its individual circuits, id what's good and what's not; rcd tests etc and work from there. It takes the time it takes.

Darn, these two ^^^^ are fast posters!

 

[R G]

The issues that you state sound very much like IR leakage on either circuits or appliances , have you not done ANY testing of the circuits at all , as already mentioned this would have been the first thing to do ....

 

[Plonker 3]

Time to get a electrician in who has a test kit and knowledge on how to use it.

I hope you didnt charge your customer for this waste of time.

 

[adam1984]

Thank you for your replies.No testing was done

The thing that is puzzling me is that the boiler would not trip the RCD but the utility room sockets do and they are on the same MCB.

Also the kitchen sockets would trip the RCD when the extension and utility room MCB's are on but when I turned off the Extension and Utility room MCB's the kitchen sockets would not trip the RCD.

Also everything was unpluged and the Martindale alone would trp the RCD.

Testing procedure duly noted.

 

[Sparkie30]

Thank you for your replies.No testing was done

The thing that is puzzling me is that the boiler would not trip the RCD but the utility room sockets do and they are on the same MCB.

Also the kitchen sockets would trip the RCD when the extension and utility room MCB's are on but when I turned off the Extension and Utility room MCB's the kitchen sockets would not trip the RCD.

Also everything was unpluged and the Martindale alone would trp the RCD.

Testing procedure duly noted.

Dont mean to be horrible mate but you cant sort this problem with a socket tester.

 

[TJ Anderson]

Basically your martindale is not suitable for this fault. Even though you are switching MCB's the neutrals are still all connected together so you would need to separate to determine which circuit has the fault and then go from there. You need an insulation resistance tester minimum and preferably a earth leakage clamp meter as well to fault find this effectively.

 

[Deleted member 9648]

Afternoon all.

This is a weird one but I thought i would ask your thoughts to satisfy my own cuisosity and apologies for long post!

Board is a Crabtree with 1no RCCB. The RCCB tripped when the TV was plugged in and socket turned on. RCCB would not instantly re-set but it did after a couple of minute.

The RCCB supplied: Downstairs power, Upstairs Power, kitchen, Extension, utility/boiler (5mcbs)

So I reset RCCB. Go back to "TV Socket", plug in Martindale socket tester, switch on socket switch and RCCB trips (do this a couple more times and keeps tripping) The TV socket is on Downstairs power MCB.

Homewoner says that its normally the tumble dryer / kettle / microwave (on the utility MCB) that ususally trips the RCCB but once reset they work again.

Reset RCCB and and all MCB's are in the ON position. Go to utility room and plug Martindale socket tester into socket, switch on and RCCB trips again. I try several different sockets and trips every time however when the boiler is fired up it doe not trip the RCCB.

If I turn off the MCB to the Utility room and try my Martindale socket tester in the kitchen sockets then it trips the RCCB. If i turn off the the Extension and utility / boiler MCB then the "TV Socket" does not trip the RCCB and nieither do the kitchen sockets.

Now the extension is actually a 2 storey extension but when I turn this MCB off it only turns the power off to the downstair extension (granted the upstairs may have been taken off the upstairs power)

I took off every socket face on the affected circuits and wiring all looked fine. I checked all cables where possible (ones clipped direct etc) for signs of damage. I asked the homewoner if they have done any DIY recently. I checked all outside equipment for signs of water ingress or damage and everything I checked looked ok and no signs of damage.

The homeowner has lived in the house for approx 4 years and on the face of it it is really modern and had a massive refurb job done by the previous owners but the current homeowner has said they have had quite a lot of problems with te house and especially with the electrics.

I think that there is a dodgy conection somewhere but I couldnt find it so must be burried in / behind a wall somewhere.The junction boxes I found were wired ok. Anyone shed some light on what they think it may be? Ways in which you would try and trace fault? No insulation resistance test was carried out.

That would be the FIRST thing I would do. Unplug vunerable equipment only,leave the rest and do a global LN-E IR test,you cant possibly rectify an RCD tripping fault without first confirming satisfactory IR readings.
Are you actually charging someone for this....?

 

[adam1984]

Apologies, the reason I am mentioning the socket tester was to say that even that was tripping the RCD with everything unplugged (My theory being that this isn't a big load)

The homeowner was not charged for me being there.

 

[R G]

By the description supplied , I very much doubt the OP knows how an RCD actually works and the fault it detects , and because of this the testing has not been done before actually asking this question here...

 

[adam1984]

Also how would you go about ramp testing this particular RCD as it was a Crabtree star breaker RCCB with 2 neutral terminals on the face

 

[adam1984]

I understand how an RCD works

 

[Anthony S]

I understand how an RCD works

You don't know and you don't know how to ramp one