All of a sudden our house RCD keeps tripping about every 5-10 minutes. It was fine for years. As far as I know nothing has changed recently. What is the easiest way to diagnose this without unplugging half of everything and keep this up until the guilty device is identified?
?Divide and conquer? is the normal method but if it?s occurring as regularly as you say, I?d be wondering about something with a thermostat tripping it regularly.
Heating elements are common causes but it may be a fridge or freezer too causing the problem.
Tim
Something with a thermostat, like a fridge/freezer perhaps?
I had a similar problem here some 25 years ago. Lighting wiring in the celing getting very hot from the fitting below - so hot that the insulation was charred!
water ingress somewhere - leaky or overflowing loft tank near some wiring?
unplug half of everything and keep this up until the guilty device is identified :-)
Start with consumer unit and isolate circuits. Take the power circuits off first which will rule out the lighting. The slowly reconnect one at a time.
Owain
Could be a loose connection in a plug, I'd look at the oldest devices I have forst see if the cables need tightening or fixing. If it;s regular could be a noiey temp control switch on whatever you have on at the time, normally it might be a fridge/freezer.
Sometimes when I chneg chennles on my TV my dyson fan switches on or chnges speed, hit the same control again and nothing happenes (to the fan anyway) Not narroeed in down to why yet or what exactly causes it. But it;s happend about 5 times this year so far.
Snag with that is most MCBs etc are only single pole switching. A neutral to earth fault can still take out the RCD.
Better to unplug things unless double pole switched.
Most likely IMHO is anything with a heating element of a certain type. Washing machine, immersion, oven etc.
First thing I'd try to eliminate is anything with a water heating element, kettle, washing machine, dishwasher, immersion heater, etc. Bear in mind unless the device has a double pole switch in the off position, if it's connected a N-E fault can trip an RCD.
After that it would be switching of individual circuits at the consumer unit but bear in mind MCBs are single pole... Maybe a deliberate N-E "fault" is required to see if that can trip the RCD. It doesn't here but thats because the supply has a shared N and E.
At least witha 5-10 minute cycle time it shouldn't take long to find.
Favourites are (as others have said) stuff with heating elements, but especially anything that heats water.
Only sensible way is to isolate stuff in turn, but if you have an electric shower, I'd start there.
If it's *that* frequent, a useful first pass might be to unplug everything and see if it still trips (i.e. RCD gone faulty)
FWIW I don't know what is double pole switched here.
Thanks to all who have responded to my post. At the times when it was tripping regularly the washing machine was on. Right now it's better (i.e. it's not tripped again for a while). In addition the washing came out of the machine much wetter that usual. Maybe it's a conincidence but .....
We don't have an immersion heater or a electric shower BTW. Our water is heated by a Combi boiler.
Also, given the change of weather recently, suspect any outside wiring, security lights etc.
Insulation test all appliances with a multimeter. A megger or PAT tester is better but an MM will pick up the great majority of faults.
NT
Erm that often is the easy way ;-)
Other suggestions here:
That is the only viable way.
Well actually removing the earths is another way. Not too practical with washers or showers though and such activities are not welcomed in a shared house.
It would allow identification of the fault, or if rubber gloves and wellies were worn permanantly, would save on repair costs.
AB
Rather depends on the age of the installation. Things like cooker switches, water heater ones and FCUs are normally DP switched. Recent 13 amp sockets too.
Mark formulated on Wednesday :
There is no easy way, you have to disconnect completely one entire circuit at a time, until you find the culprit. Both the live and neutral have to be disconnected, as either could cause an RCD to trip.
With such a frequent trip it should be easier/ quicker to find. Once you have found the faulty circuit, it will need deeper investigation.
Oh come on, for a few minutes inconvenience. Disconnect everything and switch off heaters and indeed everything you can. If it trips you have a wiring issue. if not then yet it could take a while to find the culprit, but it has to be done, as something may be in an unsafe condition, and you don't mess around with faulty electrics. Brian
The RCD in our house occasionally tripped. We never found exactly where the fault lay, but it seemed to implicate a mains feed to a brick shed: this had an overhead (hopefully outdoor-grade) wire from house to shed, stapled to a wooden batten. There was an isolating switch in the shed which removed power to lights and 13A sockets.
When that was left permanently switched on, the RCD would trip - it seemed to be more common when there was a thunderstorm, but it also happened a couple times without a storm. With the switch turned off, I don't think the RCD ever tripped.
My father in law who is an electrician investigated and carried out various tests, but he couldn't find any fault with the shed wiring.
We got into the habit of always turning off the isolation switch except when we went in the shed and needed the light on, or used its socket for driving the lawn mower.
False-triggering RCDs are a real pain in the arse because there's usually only one for the whole house so any false alarm will kill the whole house supply and if it happens when we're on holiday that's four freezers of home-grown veg and other frozen food that has to go into the bin.
Are there any RCDs which are the same size as a normal MCB and will fit into a "fuse box", so you can have an over-current and earth-leakage protector on each circuit, so if one circuit trips, the rest of the house stays up - except in really serious cases.
Our house was actually unusual: it had two RCDs in series: one very old brown bakelite one near the electricity meter, and another built into the "fuse box" upstream of all individual circuits. It was 50:50 which of the two RCDs would trip in the case of the shed being left turned on.
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