Kindly noted. I did not think about the extension leads at the time. I will do that and if to no avail I will call a sparky. It’s just I wanted to see if I could isolate and find the fault could just replace the appliance
Rcd tripping
- Thread starter Ricky786
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I had that thought very early on, but when it was clarified that an MCB often tripped at the same time as the RCD, the credibility of that possibility reduced dramatically.
Extension lead could be at fault ?
It theoretically could if the 'live' conductor were intermittently coming into contact with the 'earth one' (which might cause both MCB and RCD to trip) but it's hard to see why it would happen intermittently when the lead was not being disturbed and, in any event, might well destroy the lead.
Kind Regards, John
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It’s a real confusing one. What about loose sockets ? I’m just trying to narrow it down
A loose socket isn't going to cause an earth fault enough to trip an RCD and an MCB.
I really think you are going to need an electrician with proper test gear.. Remote, virtual diagnosis isn't going to solve this..
Indeed - I think most of us have said that at one point or another. Indeed - on the basis of what we know, and particularly given that the trips only occur 'every few hours', it might prove to be somewhat of a challenge even for a clued-up electrician with all the right kit!
Kind Regards, John
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In my old house would every so often have the RCD trip for no found reason, and when I tried to reset it, it would trip the other RCD feeding the other fuse box, and I would need to remove the load switching the MCB's off before I could reset the RCD. I have no idea why a sudden load should trip the RCD, however I know from experience it can.
I can guess on spikes etc, but that is a guess, just know a sudden load can trip a RCD.
With that in mind I would disregard the RCD tripping, and concentrate on the MCB tripping, from what you say can't be freezer as that now on another circuit, it has also tripped with washing machine unplugged, so looking for some other device switched on with a timer of some sort or a thermostat of some sort, anything else would trip it all the time, with between 32 amp and 96 amp the thermal part of the trip will operate, so load would be there for some time, between 96 amp and 160 amp either the thermal or magnetic part could operate and over 160 amp the magnetic part will operate.
All are way over the normal load on a ring final, and in the main a fuse in the plug will rupture before the thermal part of the MCB, so it seems unlikely some thing plugged in, as others have said seems likely best option is get an electrician with test gear, but if you really want to DIY job one is list all that MCB supplies.
I do not mean kettle, but what sockets, FCU, etc. So start off with say 6 kitchen sockets, and 2 kitchen FCU's need to at least know how many, including and socket in cupboards supplying waste disposal unit, oven etc.
Once you have the list with power off remove each socket one by one and inspect. I had one in the flat under my main house where water from a leaking roof had got into the socket, and the socket back was warped where clearly some thing had gone very wrong inside the socket. One can't always see the damage, but some times one is lucky.
In the kitchen it is common for kitchen fitters to extend a socket from the original position to some where more assessable, they will have joined the cables some how, so any sockets in a cupboard find out where supplied from.
I still think likely rodent attack, this may also explain time, 1 am rodent may think it is safe to move around knocking some cable.
As an electrician I would use meters, however I remember daughters it was the screw holding socket in place touching neutral to earth, and it was triggered when floor boards moved slightly as they went to bed, found by visual inspection.
I can guess on spikes etc, but that is a guess, just know a sudden load can trip a RCD.
With that in mind I would disregard the RCD tripping, and concentrate on the MCB tripping, from what you say can't be freezer as that now on another circuit, it has also tripped with washing machine unplugged, so looking for some other device switched on with a timer of some sort or a thermostat of some sort, anything else would trip it all the time, with between 32 amp and 96 amp the thermal part of the trip will operate, so load would be there for some time, between 96 amp and 160 amp either the thermal or magnetic part could operate and over 160 amp the magnetic part will operate.
All are way over the normal load on a ring final, and in the main a fuse in the plug will rupture before the thermal part of the MCB, so it seems unlikely some thing plugged in, as others have said seems likely best option is get an electrician with test gear, but if you really want to DIY job one is list all that MCB supplies.
I do not mean kettle, but what sockets, FCU, etc. So start off with say 6 kitchen sockets, and 2 kitchen FCU's need to at least know how many, including and socket in cupboards supplying waste disposal unit, oven etc.
Once you have the list with power off remove each socket one by one and inspect. I had one in the flat under my main house where water from a leaking roof had got into the socket, and the socket back was warped where clearly some thing had gone very wrong inside the socket. One can't always see the damage, but some times one is lucky.
In the kitchen it is common for kitchen fitters to extend a socket from the original position to some where more assessable, they will have joined the cables some how, so any sockets in a cupboard find out where supplied from.
I still think likely rodent attack, this may also explain time, 1 am rodent may think it is safe to move around knocking some cable.
As an electrician I would use meters, however I remember daughters it was the screw holding socket in place touching neutral to earth, and it was triggered when floor boards moved slightly as they went to bed, found by visual inspection.
If it’s possibly a rodent attack we’re would that be excatly ? Behind the walls etc ?
It could be anywhere. However, as I've recently written about the extension leads, it's hard to see how such cable damage could result in things tripping every few hours, given that presumably nothing would be 'disturbing' the damaged cables.
As has been said, we can but speculate, in ways which probably won't help you. You really do need an electrician on-site and, as I've said, even he/she might find the problem rather challenging!
Kind Regards, John
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I have been lucky, spiders, slugs, even bats, but the bats have done no damage and spiders and slugs normally make direct contract, which will trip a RCD but not likely a MCB, so looking at some existing damage and some thing disturbing things, be it some one walking on the floor above, or a rodent pushing against a cable.
It is surprising how long a fault can exist before it starts to cause problems, I put a screw through a water pipe, and it was nearly a year before it started to leak. So the 3.5 mm screw holding a socket on the wall may damage a cable in the socket box, but can take a year or so before it starts tripping things, often fault found by inspection rather than testing.
In the main it is a combination, any time a socket is removed, one can introduce a fault, using a loop impedance tester if reading is 0.8 ohm before and after unlikely anything has gone wrong when replacing, but for you to remove sockets you can introduce more faults instead of removing them.
We take about inspection and testing, and it needs to be a combination of both.
Yes, I realise that and am not criticising you. However, as I said, given that it's clearly not a problem with an 'obvious' or simple solution, folk here can really only speculate/guess - and even that has not yet really come up with any 'particularly likely' ideas about what may be going on!
Kind Regards, John
So I have done some further investigating before calling a sparky. And managed to find behind the sink unit a socket (never knew it was there) followed it and it went outside and underground all the way into the garage
Disconnected it and I think that maybe the problem. Due to damp etc
Disconnected it and I think that maybe the problem. Due to damp etc
Maybe, so I hope you're right/lucky.
However, as I've said, whilst dampness (or even frank water ingress) could well make an RCD trip, it's pretty unlikley that it would make an MCB trip, particularly a 32A one such as you presumably have on your sockets circuits.
L:et us know how it goes!
Kind Regards, John
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