How to deal with RCD tripping - external noise

[daba]

Hi guys (and gals) - here's the basics

My dis board new 7 years ago (LeGrande).

Electricity supply company laid new supply cables down the street around 2 months ago.

Have been getting sporadic RCD disconnects since then, but always 11:00 to 11:30 PM. weekdays. Weekends its 00:00 to 00:30.

I live about 150 metres from a pub, and i've done a cross-check, it's when they switch floodlights off I get the RCD trip on my dis. board.

The Electricity supply company fitted a monitor, and the feedback from that (they say) does not show any correlation between my trips and the pub lights being turned off, although they are saying there are some "spikes" on the supply.

We're getting into an argument about who should pay for any remedial work : they say I should get an electrician to test my RCD : I say they should send someone to test it.

Remember this has only started happening since they put new supply cables up the road.

Anyone got any ideas how to handle this....

TIA

 

[Zeespark]

Where in the UK are you daba?

AndyGuinness

 

[daba]

Cannock, Andy

---------- Post Auto-Merged at 23:58 ---------- Previous post was made at 23:52 ----------

Unsure if my location helps you, but can you say if this is my problem or grid supplier's ?

 

[steptoe]

it is possible that you have an internal problem that is only now showing up since they upgraded their cable.

I suppose if you get it in writing from them that its not their problem you could get your own electrician to check your install,

if he then finds that it is indeed a DNO fault you could forward his bill to them.

remember though, it is still you that has to pay the spark, but you could claim your money back from the DNO.

 

[SPECIAL LOCATION]

Hi guys (and gals) - here's the basicsMy dis board new 7 years ago (LeGrande).

Electricity supply company laid new supply cables down the street around 2 months ago.

Have been getting sporadic RCD disconnects since then, but always 11:00 to 11:30 PM. weekdays. Weekends its 00:00 to 00:30.

I live about 150 metres from a pub, and i've done a cross-check, it's when they switch floodlights off I get the RCD trip on my dis. board.

The Electricity supply company fitted a monitor, and the feedback from that (they say) does not show any correlation between my trips and the pub lights being turned off, although they are saying there are some "spikes" on the supply.

We're getting into an argument about who should pay for any remedial work : they say I should get an electrician to test my RCD : I say they should send someone to test it.

Remember this has only started happening since they put new supply cables up the road.

Anyone got any ideas how to handle this....

TIA

There could also be something failing inside you own property that you have not yet identified..

When were your circuit cables last tested?

What were the last test readings on the RCD?

is the RCD supplying the whole property or just some circuits?

A faulty dishwasher, washing machine, fridge, freezer, immersion heater, central heating controls, PIR security light, rodents in the loft.... etc.. etc...

could all cause the RCD to trip.

The pub up the road my be on a completely different supply phase to your property....

Do all your neighbors RCD's keep tripping as well???

On the balance of probability it is more likely to be something within your electrical installation not external to it....

So you need to check out all your own stuff first!

Just because two events happen at a similar time does not mean they are related!

:C

 

[Zeespark]

There is a chap named Badger on here daba, give Him a call, He lives in Burntwood, which I don't think is too far from you?

AndyGuinness

 

[steptoe]

and there was me thinking Cannock was in the bonnie land to the north,,,

:C

what do I know? not a lot obviously....... :Blushing

 

[SPECIAL LOCATION]

There is a chap named Badger on here daba, give Him a call, He lives in Burntwood, which I don't think is too far from you?AndyGuinness

Post #2 on here http://www.talk.electricianforum.co.uk/directory-uk-qualified-electricians-electrical-contractors-find-your-local-electrician/2370-find-your-local-electrician-here-list-uk-qualified-electricians-5.html

is our Mr Badger!

you can check if he is local enough..

 

[Steve3948]

Yeah I agree with Special Location, it's most likely internal.

I had a call out over the weekend, trip had started going from Wednesday last week once or twice a day, until Saturday when they could not reset it and called me.

I found the kitchen ring had a hard fault on it, even though everything to their knowledge was unplugged.

I decided to leave circuit disconnected, get them running again and call back Monday.

On Monday after breaking the circuit down as you do I ended with fault between two points, kitchen to landing socket.

The kitchen socket had a mirror about 200mm to the right of the socket, how long has that been there I asked, about 5 years was the reply.

Not that then I thought, but still decided to remove mirror and put leads between picture hook and my neutral, BINGO.

Dug out plaster and repaired, power back on all good, however client wanted to know why it had taken 5 years to become a problem.

My answer someone must have nudged the mirror.

My point is, I dismissed that mirror to start with when I had a visual look for problems because the client said its been there years and it was not in line with socket.

It could be anything in the OP's house, but you tend to relate it to something that has just happened, and that is not always the case.

 

[park1]

Hi guys (and gals) - here's the basicsMy dis board new 7 years ago (LeGrande).

Electricity supply company laid new supply cables down the street around 2 months ago.

Have been getting sporadic RCD disconnects since then, but always 11:00 to 11:30 PM. weekdays. Weekends its 00:00 to 00:30.

I live about 150 metres from a pub, and i've done a cross-check, it's when they switch floodlights off I get the RCD trip on my dis. board.

The Electricity supply company fitted a monitor, and the feedback from that (they say) does not show any correlation between my trips and the pub lights being turned off, although they are saying there are some "spikes" on the supply.

We're getting into an argument about who should pay for any remedial work : they say I should get an electrician to test my RCD : I say they should send someone to test it.

Remember this has only started happening since they put new supply cables up the road.

Anyone got any ideas how to handle this....

TIA

If its external, its either transient current or transient voltage, the latter being the more probable, a poor joint on the cable could cause the RCD to trip, any neighbouring property's effected?

 

[Evans Electric]

As said above , never rule out the First Law of Coincidence .

And Mr Badger is indeed in your area.

( It could even be him causing the problem if he,s testing his Christmas lights !!!! When he switches them on the lights dim in B,ham)

 

[Bacon]

As said above , never rule out the First Law of Coincidence . And Mr Badger is indeed in your area.

( It could even be him causing the problem if he,s testing his Christmas lights !!!! When he switches them on the lights dim in B,ham)

Bloody good light show i must say having seen them.

 

[daba]

Thanks for the replies guys....

For those who think it is a coincidence, and that the fault is most likely internal, I thought I had pretty much nailed it down to external influence, as I checked with the pub on the last 4 of the occasions that the trip had gone. Each and every time they had just turned off their car-park and beer garden lighting. You just don't get coincidences like that.

On the latest 2 occasions, the DNO had their monitoring device fitted, and I duly gave them the times of the trips to correlate with their recording. Now I don't want to accuse them of lying when they tell me the trace shows no sign of disturbances at those specific times. Does anyone think the DNO would let me have a copy of the recordings they took for 10 days? I'm curious to see it.

I even spoke to the pub landlord, and I told him that there are only 2 switches, one for the car-park, and one for the beer garden. When he asked me how I knew, I explained that I hear 2 clicks on my cordless headphones every night at said hours (The RCD doesn't trip everytime - just occasionally, on average once to twice a week).

Rule out the Fridge/Freezer, it's been replaced since the problem started (for another reason).

Rule out the washing machine - who washes after 11pm at night?

Rule out the dishwasher - never on when the RCD trips.

Rule out the central heating - if on, it's programmed to go off at 10:30pm.

Rule out the immersion heater - I don't have one.

Rule out the PIR security light - I would be getting trips at all other times, but I don't.

Rule out rodents in the loft (at least I hope so !!) - I would be getting trips at all other times, but I don't.

There is just so much of a correlation to the pub lights, that it just has to be - if I were a gambling man I'd put a huge amount on it.

And also I said that I have only had this problem since they upgraded the supply network up the road - and I believe the pub is the last property it feeds.

I could check with the neighbours - is it every third house I should ask ? Is that the way the DNO will have split the load on the phases ?

I had no luck getting hold of Mr. Badger today - I'll try again tomorrow - and yes I'm sure I must have seen his lights !!

 

[Manator]

I do not think this problem is internal, I have a sneaky idea that the PME is not configured correctly probably due to the fact that the replaced cable was not rodded at the joint to a TNS supply.

You really should have a test done on your installation to rule out any internal faults though.

 

[daba]

Thanks Manator, although I'd be glad of a heads-up on your TLA's.... IF I knew what they stood for, I'd read up and understand them.

PME ?

TNS ?

"You really should have a test done on your installation to rule out any internal faults though. "

If I had internal faults, I would be getting trips at some other times of the day, such as when things are switched-on/off. I don't get ANY trips whatsoever at any other times - only 11:00 to 11:30 PM weekdays, and 12:00 to 01:00 weekends. The pub has a late licence Fri and Sat. IMHO the evidence is overwhelming.

This test would cost me money that I have no guarantee of recovering, even if the test proves my installation is fine. When I talk to the DNO line-manager again, I will directly ask him if they will pay for a PASS test. If they won't, I don't see the need to test my installation which was perfectly OK until they overlayed.

 

[springcrocus]

Why don't you ask the landlord to turn his lights on and off again during the day, as a test, to see if your RCD trips then. It might bolster (or disprove) your case.

 

[steptoe]

Thanks Manator, although I'd be glad of a heads-up on your TLA's.... IF I knew what they stood for, I'd read up and understand them.PME ?

TNS ?

"You really should have a test done on your installation to rule out any internal faults though. "

If I had internal faults, I would be getting trips at some other times of the day, such as when things are switched-on/off. I don't get ANY trips whatsoever at any other times - only 11:00 to 11:30 PM weekdays, and 12:00 to 01:00 weekends. The pub has a late licence Fri and Sat. IMHO the evidence is overwhelming.

This test would cost me money that I have no guarantee of recovering, even if the test proves my installation is fine. When I talk to the DNO line-manager again, I will directly ask him if they will pay for a PASS test. If they won't, I don't see the need to test my installation which was perfectly OK until they overlayed.

1. why? it may be that the DNO upgrading the supply simply showed up the inadequacies of your installation........

2. most things in life do, but if it doies show your installation is at fault then you should be able to claim it back. why should it cost the electric company money to prove they are not at fault? is there a difference?

 

[Manator]

Thanks Manator, although I'd be glad of a heads-up on your TLA's.... IF I knew what they stood for, I'd read up and understand them.PME ?

TNS ?

"You really should have a test done on your installation to rule out any internal faults though. "

If I had internal faults, I would be getting trips at some other times of the day, such as when things are switched-on/off. I don't get ANY trips whatsoever at any other times - only 11:00 to 11:30 PM weekdays, and 12:00 to 01:00 weekends. The pub has a late licence Fri and Sat. IMHO the evidence is overwhelming.

This test would cost me money that I have no guarantee of recovering, even if the test proves my installation is fine. When I talk to the DNO line-manager again, I will directly ask him if they will pay for a PASS test. If they won't, I don't see the need to test my installation which was perfectly OK until they overlayed.

PME and TNS are the supply characteristics most installs in this country historically have been TT and TNS, TT is when the supplier does not provide a connection to earth and the hous holder is responsible for the final earthing, this is done by providing an earth to the general mass of earth by inserting a rod or multiple rods.

TNS is wher the supplier is responsible for the earth and provides this earth via the outer sheath of the supply cable.

Another common supply introduced later is the TNCS, this is when the supplier supplies the earthing which is shared by the neutral conductor and is split on delivery to provide a separate earth connection within the installation.

PME is now what all network providers have been instructed to supply, PME (Points of Multiple Earthing) should not be confused with TNCS as is often the case, the differences whilst subtle are indeed different, as our distinguished member Steptoe will attest to,

 

[daba]

1. why? it may be that the DNO upgrading the supply simply showed up the inadequacies of your installation........2. most things in life do, but if it doies show your installation is at fault then you should be able to claim it back. why should it cost the electric company money to prove they are not at fault? is there a difference?

1. My installation has had no significant tripping for the 7 or 8 years since my dis board was installed (i guess once or twice a year) - each time it was attributable to something internal, like once my dishwasher sump flooded the motor. Each time the RCD told me something was wrong, it got fixed and that was it. My installation has had no tripping at ANY OTHER TIMES - I can't say it more plainly - each time it trips, I check with the pub, and ALWAYS they have just turned their lights out.

Please explain how an electricity supply can "show up the inadequacies of your installation"

I don't believe in a better supply showing up inadequacies - if I had RC issues, the RCD should have tell-taled it before - my supply runs 24/7 with no RCD trips - but it is now tripping since a "better" (lower-impedance) supply was installed - that just means I'm getting more noise into the dis board, and the RCD is acting upon it.

Sorry steptoe.... unless you can come up with a genuine scenario where the overlay can possibly cause RC faults, I'm not buying it.

2. Why should it cost me when I have enough evidence to say that what they have done is causing me nuisance tripping. They were the last people to do any work involving my supply, surely it is up to them to prove it is not there wrong-doings.

 

[Doc Hudson]

When was your installation last inspected and tested? BS7671 wiring regulations recommend a domestic dwelling is inspected every 10 years or at a change of ownership. Do you have up-to date test results? Periodic inspection and testing would verify the condition of the cables and earthing within the property. All wiring, including yours deteriorates with age, RCD's do not always trip when something is switched on or off, e.g. moisture ingress into a poor joint or damaged cable can cause problems. Steve3948 gives a typical illustration in his post 9. The moisture content within the plaster walls or movement of floorboards, doors, putting something on a shelf are all none electrical related issues than can cause RCD's the trip. Are all the connections in your fuse box tight? Is your RCD over sensitive? Does the installation have one global RCD or multiple RCD's installed? do they all trip or just one? There is no reasonable reason why any supply company should have to test and prove these items in anyones home.if a homeowner has failed to follow the industry recognised testing and inspection periods themselves. I am not saying your problem cannot be external, but you need to step back from your unproven ideas and go back through a systematical test of your own internal wiring first. As has been said earlier do you see any of your neighbours power tripping off at the same time as yours?

Doc H.