Got an RCD issue I could do with some advice on please.
RCD covers 3 circuits, upstairs lights, upstairs sockets and downstairs . It is tripping on downstairs sockets; even with all devices unplugged. Tends to stay OK for about 20 minutes; when you reset it, sometimes takes two or three attempts before it stays connected. When I switch the downstairs sockets out, no problems. I've run one of those little 3-pin socket testers round all the sockets and they're coming up good. My money's on a faulty circuit breaker but i'd welcome any sensible advice.
Note; not planning to dig too deep myself, merely trying to cut the diagnostics fee down a bit!
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Had a similar issue on a lighting circuit. Was the circuit breaker. When you say you 'switched the downstairs sockets out' do you mean you pulled all the plugs out? in which case could be a burned out socket.
I'm not an electrician but can find my way round most issues.
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Had a chat with friends on Facebook, common consensus seems to be condensation in a downstairs socket causing a live to earth or nutral to earth leakage; my house is stone built and dates from late 18th century. I do have osmotic damp proofing but it has been exceedingly wet down here of late, and the high humidity is a perfect breeding ground for condensation.
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Had a chat with friends on Facebook, common consensus seems to be condensation in a downstairs socket causing a live to earth or neutral to earth leakage; my house is stone built and dates from late 18th century. I do have osmotic damp proofing but it has been exceedingly wet down here of late, and the high humidity is a perfect breeding ground for condensation
You'd need a lot of condensation to cause that problem. I'd have hoped the plug in tester would have shown up a live to earth fault. Neutral to earth, less so. My method would have been to use my Megger as it not only tests insulation (high resistance) but also measures low resistance and thus, earth continuity. Not sure if the electrician you've got coming will do this first, or will test the RCD first. Mind you, they will almost certainly have an up to date thingy to take the place of a Megger, no winding a handle needed.
SP - who is not a sparky but does have a degree in Electrical Engineering
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RCDs will also trip if there's a neutral to earth fault in the circuit which your plug in tester won't show.
Check for birds nests in loft if upstairs lighting circuit affected. Isolate fridge/freezer if you can.
RCDs can "wear out" (actually, the little magnet inside becomes de-gaussed) so you could just swap it out and see if it fixes the problem.
Edit: crossed posts.
Last edited by: Fursty Ferret on Sun 3 Jul 16 at 12:44
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Since I've got power upstairs and the kitchen's unaffected, I've rigged up an extension lead to power the telly (on pain of death from Mrs HM should I not!) and will call a professional in tomorrow. I am happy enough with 6 or 12 volts, even 24, but mains is something I don't unduly mess with if I can possibly avoid it. Thanks for the advice chaps.
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Had a similar problem last week.
Immersion heater thermostat (under the cover on top) was failing and damp.
(Trying to remove a 40 year old ( thermostat in degrees F) - immersion heater was fun)
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That reminds me, and I have put it forward on here before: an electrician mate of mine tells me that when called in for fault finding he goes to the immersion heater first as in his own experience they very often slowly break down in some way and can cause no end of issues.
I don't know a lot but it can't be good for long term reliability to have an electrical thingy pumping out extreme heat often splashed and drowned with very cold water while all the time in a humid possibly high limescale environment.
Maybe isolate it and see what happens.
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From time to time all our electricity goes off. If the other house still has juice it means that our mains connection has tripped. Often happens late at night when it is raining.
I have to go outside, open a big box, unscrew the lid of a smaller box inside it and then operate trips and switches in the right order to make the juice come back. I can never remember what the right order is of course, so trial and error in the dark and rain are the order of the night.
So far I haven't given myself a fatal shock.
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>> Maybe isolate it and see what happens.
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No need. I don't have an immersion heater, but thanks for the tip.
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I remember we had an issue with the RCD tripping randomly and just could not fathom it out.
Then got my sparky cousin to come in and check it out and everything looked fine but it tripped while he was here but still couldnt find it.
Then, purely by chance, we realised it was my son's laptop charger and this was tripping the RCD everytime he plugged it in!
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>> Then, purely by chance, we realised it was my son's laptop charger and this was
>> tripping the RCD everytime he plugged it in!
If mine goes first question is 'has somebody just turned something on'? One occasion obviously the tumble drier, in another the washer on spin. A third was a short in a light fitting - insulation trapped and breached.
If not and it keeps tripping it's isolate everything possible on the circuit and gradually switch things back on.
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Coincidentally we've been getting something similar since Thursday. Prime suspect is the freezer, since that starts and stops repeatedly and autonomously. The only other appliances on the ring in question are the Infinity modem, router and associated gubbins; nothing that hadn't previous run trouble-free for months. There's another socket, seldom-used socket on the garage ring but connecting the freezer to that gives the same symptoms.
The freezer is nine years old and previously trouble free; the consumer unit and RCDs are new since we moved here in 2010. With holiday approaching we need to resolve this. I did wonder if the RCD had become over-sensitive, as Fursty suggests. Otherwise, assuming the freezer itself is not actually faulty but merely over-eager, would I do best to have a new, RCD-less socket fitted just for that?
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Maybe insert an "In Line RCD Extension Lead" for the freezer.
That might trip first and identify that it is to blame.
They cost less than £20.
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Do you mean the sort that plugs into the socket, Henry, then takes the appliance plug? If so, I have one of those from the days before we had RCDs in the consumer unit.
It went off again during the night but it's been all right now for four or five hours. We'll see.
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>>Do you mean the sort that plugs into the socket, Henry, then takes the appliance plug? If so, I have one of those
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That is an even better option as it is zero cost to try it.
The hope is your plug in RCD will be the first to trip rather than the consumer unit one.
( the extension lead version was the first that popped up on Ebay )
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Apologies for delayed result announcement, been away.
It turned out to be an earth leakage on one of the wires between two sockets. I was away when the sparkies came (local firm, very efficient and old-fashioned enough to just send you a bill) but Mrs HM tells me they've put something in the consumer unit which is called a "radio socket"; effectively it reduces the offending socket to a 20A loading but it can still be used without having to remove all the wiring from the wall.
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>>> something in the consumer unit which is called a "radio socket"; <<<
This caused some thinking time! I guess that they have split the old ring into 2 parts , removing the offending length of cable and rated one part as a new spur at 20A with a new RCD, and put in a new 'return for the ring', leaving that part as 30A ring.
Had somebody been putting screws in the walls?
Last edited by: sherlock47 on Mon 11 Jul 16 at 07:44
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....yes indeed - "radial socket" ;-)
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>> This caused some thinking time! I guess that they have split the old ring into
>> 2 parts , removing the offending length of cable and rated one part as a
>> new spur at 20A with a new RCD, and put in a new 'return for
>> the ring', leaving that part as 30A ring.
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>> Had somebody been putting screws in the walls?
>>
Not as far as I'm aware. Your explanation does make sense though; Mrs HM dealt with the sparky as I'm currently on long-distance, so I was going on what he told her and it probably got lost in translation.
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Thanks, Henry. With the freezer connected through the plug-in RCD, each incident still tripped the one in the consumer unit.
Once it starts happening it can trip every 20 minutes or so - not that it's that precise. When it's happening frequently, unplugging the freezer seems to stop it, so I still suspect the freezer - but of course I can't leave it unplugged all day to see if it stops altogether. There's no easy and secure way to run an extension from a ring on the other RCD (inside the house) to see if it trips that instead.
I've probably learned as much as I can about the problem. The electrician who installed the consumer unit and the garage ring is approachable and decent so I'll get him in to check it.
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It was worth a try. The consumer unit RCD may be more sensitive and is still the first to trip.
After all you tests it does point to the freezer causing the problem.
While you are at the freezer have you tried switching either the temp down or the rapid freeze switch on to see if the fault is invoked ? This might add further conviction to your suspicions.
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We've been using the rapid freeze button a lot since the problem began. (Just looked and it's showing -29°C; turned it off for a bit.) My guess is that the trip happens when the motor cuts out, because it's never happened again immediately on restarting.
I wondered whether it would be possible to swap the RCDs round, but they're of different ratings. This one is 80A, the other 63A.
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Would it be an idea to get a sparky or refrigeration engineer to look at the freezer?
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Well, we've lined up a friendly (really - someone we know well) local electrician to look at the problem but, perplexingly, it seems to have gone as suddenly as it appeared. It's been three days now since the last trip, and we're not conscious of doing anything different. Something in the weather, perhaps: warmer days making the freezer run more continuously rather than cycling on-off? No idea, but it's making it harder to work on just now!
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I realise the problem seems to have gone away now, but if it was tripping then something must have been causing it... Not sure I'd be putting a higher rated RCD in - surely that's just masking the problem? The last thing you want if you're going to be away is an electrical fault getting worse!
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The mains ring in my workshops started tripping it's RCD now and again a few weeks ago. Luckily the consumer unit is in the building rather than up at the house so t'was easy to reset' I wasn't too worried, I still had lights, but there's a freezer in there. I plugged in a small light so I could see from the house if the mains were still on when we went to bed and they did stay on all night but tripped again a few days later.
I have about 25 sockets on the ring so I wasn't looking forward to searching for the short. Happily, I went into the caravan to do something which involved the 240V power and nothing worked. Outside, I found the problem, I had run over the outside cable when moving the van a few feet, the cable had pulled out of it's plug and was resting on the ground....and it was wet !
Rewired it back in and all has been tickety-boo since. It's not always the place you think of first !
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Any sparkies on here please? - Fullchat
