Why would circuit breaker trip every few hours?

scarletjim

Yes the next plan would ideally be to test the freezer on another circuit, but unfortunately it's hard-wired, and I'm not confident to plug-wire it myself.

So I think I'll leave it overnight as suggested, and if the electrics don't cut out, then I think I've at least found my problem (though I think Heedtheadvice disagrees, so I'm not sure if there is a flaw in my logic somehow...)

If I establish it is the fridge freezer, then what? Call an electrician? Call an appliance repair person? Fault-find it myself (how)? Buy a new one? (Hopefully not, as it looks horrendously expensive...)

brightontraveller

scarletjim wrote: »

Yes the next plan would ideally be to test the freezer on another circuit, but unfortunately it's hard-wired, and I'm not confident to plug-wire it myself.

So I think I'll leave it overnight as suggested, and if the electrics don't cut out, then I think I've at least found my problem (though I think Heedtheadvice disagrees, so I'm not sure if there is a flaw in my logic somehow...)

If I establish it is the fridge freezer, then what? Call an electrician? Call an appliance repair person? Fault-find it myself (how)? Buy a new one? (Hopefully not, as it looks horrendously expensive...)

I doubt heeds an engineer ?

Sorry but if you can’t wire a plug unlikely to be able to diagnose/repair successfully?


Try contacting manufacture see if there's a workaround , modification etc (wouldn't hold much hope with them though)


Move it onto dedicated circuit not protected by RCD?

Replace faulty component in appliance? If age related this has better chance? But if its newer ff then likely design fault/flaw thus replacing component doesn't cure for long if at all.


You can add resistors, change capacitors on appliance etc appliance engineer job really but would say 95% of them wouldn’t have a clue how to do so or equipment for diagnostics etc?

Try changing main RCD some are more sensitive than others problem is they tend or at least shouldn’t be mixed in CU e.g MK cu other make RCD ,

Put on own dedicated circuit with RCBO doesn't stop tripping but means only that circuit goes faulty,

Change rating of RCD /RCBO etc( questionably but some certainly would ?)


Buy new appliance,,,,,

There are others but above covers the basics

Heedtheadvice

Hi all, sorry if I have thrown an electrical spanner in the logic works!:eek:
The logic:
Power goes off
No trips of switches either mcb or echo/rcb (that was correct was it not?)
Hence no over current being drawn and no earth leakage fault.
Stop me if I am wrong here!
(Referenced response to Ben84 from OP on clarification regarding no tripping of switches unless 'test' is pressed)

So logically intermittent open circuit somewhere in the supply to sockets. That might be in wiring (including connection to the circuit that supplies your freezer), the feed out of the consumer unit or within it. Those who support the idea that the freezer causes a power failure in other circuits can maybe explain how though I accept the very small power drawn by it might have a slim chance of causing a high resistance joint in a common location to warm up bit and cause a problem, however unlikely). Could still be rodent damage as previously mentioned but that is more likely to cause an RCD to trip.

Did you not write that the lights stayed on? If so (and presuming they are also fed, as is typical, via the rcb) that indicates the fault is not with the rcb)
That leaves a connection problem.
The freezer connection (the attributable cause logic) is conceivably a possible link but not the likely cause as there will be other reasons why the intermittency may be activated or not and you have not discounted those to reach a conclusion.

I say call out the expert as what more can you do apart from more guesswork whereas an electrician can diagnose quickly (if competent so selecting a registered one gives that confidence of competency) or you can call out an appliance technician who may or may not be qualified to diagnose the fault on just a small part of your installation however good he or she may be.
Hope that explains how I see the different logic.

There will probably be little difference in cost to do the diagnosis (circuits vs one appliance) either way and a lot less than buying a new freezer -which may not cure the problem! -or potentially losing all your frozen food.

........for Brightontraveller, I am an engineer of over 40 years experience in electrical & electronic engineering ranging from design, installation, test and repairs. Retired so no axe to grind, gain no benefit from this thread but hope others can especially the OP saving money time (and hopefully the possibility of a fire!!) and if I write erroneously am more than happy to be corrected and still learn.:). There have already been some very good posts explaining the technical aspects (including from you) so why the snide comment framed as a question regarding heeds ?? OK, maybe I missed something in my dotage but would you explain please?

scarletjim

Oh dear, I think I might have caused lots of unnecessary confusion on that point. This picture should help (if it works):

http://img3.uploadhouse.com/fileuploads/22462/22462583c35a36819f1c99c05e48bdaa35357a69.jpg

On the far right, there are 6 black switches - none of these move when the power cuts out. However what DOES move is the single black swith just above the 'RCD protected circuits' sticker. It reverts to the middle (tripped) position after a few hours of being reset. Does that make sense? So what I meant was that none of the individual switches trip, but that main one does.

(NB. The red side appears to work regardless, so we always have lights on even when the 'green side' keeps failing).

screwedagain

A picture paints a thousand words!

It looks to me like your RCD is tripping after all. So you have an earth leakage on one of the circuits to the right. Most likely the kitchen sockets based on your earlier diagnostics with the fridge freezer (in that the RCD doesn't trip when you isolate the FF)

That should be enough info to give a good spark a helpful starting point in properly diagnosing the problem, or at least ruling out a problem with the fixed wiring in the house.

scarletjim

Last night, with some Skype help from an electrician, we disconnected the freezer from its hardwired installation, put a plug with 13amp fuse on it, and plugged it into a socket on another circuit. Within a few hours, the problem happened again. So presumably we know now that it can't be anything to do with the socket, and must surely be the fridge freezer? (Ok, I guess the RCD could be over-sensitive, but if so then I'd expect it to trip sometimes from other appliances, which it doesn't...)

Of all Brightontraveller's suggestions above, replacing the faulty part of the appliance seems most sensible to me - but who will be best to tell which part that is? If we are talking about inconsistent current leakage, will an appliance repair man be able to identify that, and the cause of it? Or (worst scenario) do I need both an electrician and an appliance repair person?

brightontraveller

Heedtheadvice wrote: »

........for Brightontraveller, I am an engineer of over 40 years experience in electrical & electronic engineering ranging from design, installation, test and repairs. Retired so no axe to grind, gain no benefit from this thread but hope others can especially the OP saving money time (and hopefully the possibility of a fire!!) and if I write erroneously am more than happy to be corrected and still learn.:). There have already been some very good posts explaining the technical aspects (including from you) so why the snide comment framed as a question regarding heeds ?? OK, maybe I missed something in my dotage but would you explain please?

All that experience should tell you Ask them the fault ? e.g. light not working, rcd tripping etc (if possible offer over phone remedy ?)
(Some might ask if they have done any diy, any building works or have problems with pest. flooding etc ) Ignore 99% of remedies they may have attempted ? Its ultimately your name on the ticket you that they come after if anything’s wrong saying client said attempted that is a fools path?

brightontraveller

scarletjim wrote: »

Last night, with some Skype help from an electrician, we disconnected the freezer from its hardwired installation, put a plug with 13amp fuse on it, and plugged it into a socket on another circuit. Within a few hours, the problem happened again. So presumably we know now that it can't be anything to do with the socket, and must surely be the fridge freezer? (Ok, I guess the RCD could be over-sensitive, but if so then I'd expect it to trip sometimes from other appliances, which it doesn't...)

Of all Brightontraveller's suggestions above, replacing the faulty part of the appliance seems most sensible to me - but who will be best to tell which part that is? If we are talking about inconsistent current leakage, will an appliance repair man be able to identify that, and the cause of it? Or (worst scenario) do I need both an electrician and an appliance repair person?

If cooker has plug point (Link A) for the 7 odd pound id give F/F with separate RCD (Link adapter plugged into cooker outlet if it has plug point a go ?



The tricky bit is now is now knowing does appliance have a fault ? Is that fault alone that’s exceeding 30ma Or is the appliance along with combination of items combined creating a fault current exceeding the 30ma e.g. F/F 15ma kettle 10ma blender 12ma thus making RCD trip on the circuit covered by RCD

Link A
http://www.screwfix.com/search?search=Cooker+Switch+%26+13A+Plug+Socket+White

Link B
http://www.screwfix.com/p/masterplug-rcd-adaptor/63731?_requestid=181690

Or get a good electrician of appliance engineer would be able to be able to do so

scarletjim

Sorry for being thick but I don't understand what adding the RCD adaptor would achieve - I already know via proces of elimination that the FF is tripping the 'main' RCD (I do know that now don't I?) - if I do as you suggest, won't the FF just trip this RCD in exactly the same way? Looking at the Q&A on Link B, the person answering the question suggests that this product will trip at 30ma, and is intended to add additional safety if your main RCD has a higher rating, say 100ma. But my problem is the opposite, my main RCD is tripping because of my FF but with apparently no reason to do so. What will fitting the RCD adaptor tell me that I don't already know?

In terms of your question about the combination of leakages, I doubt it can be this, as one night I left all other switches off, and unplugged all other appliances on the FF switch, so that only the FF was running, nothing else, and it still tripped. Another night, I had everything on except the FF, and it was fine...

brightontraveller

scarletjim wrote: »

Sorry for being thick but I don't understand what adding the RCD adaptor would achieve - I already know via proces of elimination that the FF is tripping the 'main' RCD (I do know that now don't I?) - if I do as you suggest, won't the FF just trip this RCD in exactly the same way? Looking at the Q&A on Link B, the person answering the question suggests that this product will trip at 30ma, and is intended to add additional safety if your main RCD has a higher rating, say 100ma. But my problem is the opposite, my main RCD is tripping because of my FF but with apparently no reason to do so. What will fitting the RCD adaptor tell me that I don't already know?

In terms of your question about the combination of leakages, I doubt it can be this, as one night I left all other switches off, and unplugged all other appliances on the FF switch, so that only the FF was running, nothing else, and it still tripped. Another night, I had everything on except the FF, and it was fine...

Clarify cooker has plug point?
You doubt its combination ( not intending to sound patronizing but not really going to help you explaining all the reason doesn't mean you'll understand ?)

Cookers not on RCD You can spend the £7 if it cures fault /symptoms you need spend no more potential to gain if it doesn't take it back no loss or call out engineer they'll likely do same but charge you more than £ 7