Fuse box trip switch trips randomly

MaceFace

Hi Folks,

I've been my home a few years, and when we took ownership we were advised that the fuse box would trip sometimes but if it did, it would be down to an appliance we were using.
Since then, we have found that the switch trips every so often (weeks or months) almost at random. It tends to be more during the day, but not necessarily as a result of having a high load or even any appliance running.
It can also trip when we are out or on holidays so it really is at random.

I spoke to an electrician we had out the house before and he reckons it could be something to do with an external socket we have. I reckon he just latched on to that idea as the landscaper we had in said to him that one of the external sockets appears to go nowhere (the cable goes under the garden to somewhere he can not locate). The sparky reckoned there could be a crack in the cable letting in moisture, tripping the switch. I'm not really convinced as it can happen in the middle of summer in very dry periods. He suggested that the external cable was brought into the house "somewhere" other than the fuse box. Possibly tied to an internal socket (a simple twist of the wires to make a connection) and I could examine each socket in the house to try and locate.

The fuse box may actually be two (or possibly three different boxes). The one that trips is the more modern box with the switches that trip which we can just flip back on. There is another box just above it with more switches, but there is a master fuse in this, like you would have seen in fuse boxes 10 or 20 years ago (a bottle shaped fuse about 4-5" long).
There is another box which I was told controls the electric showers (we have one up stairs and one downstairs), but not sure if that is a fuse box of some sort or just ensures only one is switched on at a time.
Also, we have a large extension on the house almost doubling the size of it if that matters.

The previous owners provided us with documentation showing an inspection of the property and that the electrics were all fine.

I'm a little hesitant about getting an electrician in just because it seems like a very odd problem that may result in a complete rewire job when maybe the problem is something simpler.

Has anyone any suggestions of what may be the cause of the switch tripping at random times? Things I can try?

Thanks!

2011

I am assuming that it is an RCD that is tripping?
Can you please post a photo of the device that trips?
What circuits do you loose when it trips, just sockets?

This reply assumes that it is an RCD:
An intermittent fault is always the most difficult to find, however a competent electrician should be able to pinpoint this for you. Sometimes the simplest option is to install an RCBO per circuit (combined RCD and MCB). It will then be possible to work out which circuit has the issue and it will minimize the impact of the device tripping.

If a particular cable is under suspicion as you suggest a quick insulation resistance test will rule it in or out. If you electrician has not done this already it may be time to look for someone else. It may also be prudent to have the wiring checked while you are at it.

MaceFace

Thanks 2011.
I'll post a pic of the board later when I get home.

The switch that trips is a master switch for the board, which I enable again by turning rather than flicking (if that makes sense).
Almost everything in the house goes off, including lights.

I'll post a pic later and hopefully that will help make it clearer.

Thanks again.

MaceFace

Hopefully attached is the picture of my fuse board. The switch that trips is the bottom right. No other switches ever flip....

Any thoughts?

2011

Do you not mean bottom left??
Assuming that it is bottom left, that is an ELCB otherwise known as an RCD so my earlier advice stands.

Judging by the appearance of the board I would recommend that you get the installation checked over throughly.

MaceFace

2011 wrote: »

Do you not mean bottom left??
Assuming that it is bottom left, that is an ELCB otherwise known as an RCD so my earlier advice stands.

Judging by the appearance of the board I would recommend that you get the installation checked over throughly.

Yes, sorry. Bottom left.

I'll call someone to check it over. Thanks

BOARDHOG

The elcb on the bottom left should be for sockets only. If this trips your lights should still be on. The switch on the top left is your main switch which will turn off everything. That's assuming it's wired correctly.

Pod123

Bought house 6years approx. Got all electric renewed i.e new trip switches etc.
This trip switch tripped this morning. Nothing new plugged in.
What can cause this ?it’s the trip switch with the yellow button.
Thanks for all advice

meercat

Pod123 wrote: »

Bought house 6years approx. Got all electric renewed i.e new trip switches etc.
This trip switch tripped this morning. Nothing new plugged in.
What can cause this ?it’s the trip switch with the yellow button.
Thanks for all advice

Most likely an element. (Usually neutral to earth fault but not exclusively)I’d check your immersion first then a process of elimination. Unplug all your appliances and see if it trips. I see it’s rated 40amp. I’d advise a 63amp too.

greasepalm

Interesting also got an issue every now and again my one trips for sockets as lights still work.Went through the motions of unplugging things but as no set time it would go off .Now have a thread reference to follow.

rx8

I have been having an ongoing similar problem for a good while now...

The RCD randomly trips, sometimes in the middle of the night, when there is nothing in use or sometimes if I set the timer on the Zappi to charge the car, it will trip when the charge starts, though not all the time, most times it's fine. One time it went about 6 times in the one day, then it didn't go off for a couple of months. The switch always resets without a problem and continues to work normally until the next time.
I'm beginning to think that the RCD itself is at fault. Is this possible, has anyone ever encountered a faulty one like this ??

Thanks.

Malcomex

rx8 wrote: »

I have been having an ongoing similar problem for a good while now...

The RCD randomly trips, sometimes in the middle of the night, when there is nothing in use or sometimes if I set the timer on the Zappi to charge the car, it will trip when the charge starts, though not all the time, most times it's fine. One time it went about 6 times in the one day, then it didn't go off for a couple of months. The switch always resets without a problem and continues to work normally until the next time.
I'm beginning to think that the RCD itself is at fault. Is this possible, has anyone ever encountered a faulty one like this ??

Thanks.

Could be a few things

Damp somewhere this time of year ,usually at a joint or outside

Faulty Rcd

Faulty appliance

Wiring fault/s

Malcomex

An IR test of the installation will prob show up low readings i'd expect

If not you could try swopping out the RCD


Do car chargers connect to the main RCD. I would have thought they would be independent of it?

I'm not familiar with them though

meercat

rx8 wrote: »

sometimes if I set the timer on the Zappi to charge the car, it will trip when the charge starts, though not all the time, most times it's fine..

Is the car charger plugged into a conventional socket.it should be on a dedicated circuit if it’s a charge point outside

rx8

meercat wrote: »

Is the car charger plugged into a conventional socket.it should be on a dedicated circuit if it’s a charge point outside

Thanks for the replies... The car charger is on a dedicated circuit. It's only been there since last September. The problem has been there for years now at this stage.

meercat

rx8 wrote: »

The car charger is on a dedicated circuit. It's only been there since last September. The problem has been there for years now at this stage.

And when it trips does it turn off your car charger

rx8

" And when it trips does it turn off your car charger"

Yes,

Picture of board attached. The whole top row shuts off when RCD trips.
Bottom row is lights, cooker, electric shower etc.

newuser555555

rx8 wrote: »

" And when it trips does it turn off your car charger"

Yes,

Picture of board attached. The whole top row shuts off when RCD trips.
Bottom row is lights, cooker, electric shower etc.

why is it that all garo boards look incredibly cheap

meercat

rx8 wrote: »

" And when it trips does it turn off your car charger"

Yes,

Picture of board attached. The whole top row shuts off when RCD trips.
Bottom row is lights, cooker, electric shower etc.

I’m assuming no7 or 9/10 is your car charger. It shouldn’t be connected to your rcd. It should be on its own rcd protected circuit ( most commonly rcbo protected).

rx8

7 is for Kitchen sockets, 8 is the supply to the Inverter, (I have Solar Panels) 9/10 is the Car Charger.

The switch has been tripping way before the Solar and Zappi were installed.

Malcomex

Shouldn't an inverter be separate as well ? I'm not familiar with them either

I thought they required an AC or even a B type Rcbo could be totally wrong there

Either way there's a lot of equipment connected to that RCD

Malcomex

I'd be separating the inverter and car charger from the main RCD anyhow

After that an IR test off the installation probably

Malcomex

If there's no installation faults showing or anything obvious

Prob swop out the RCD or fit some Rcbos

meercat

rx8 wrote: »

The switch has been tripping way before the Solar and Zappi were installed.

It’s not correctly connected. You’re overloading the rcd. As pointed out you need 2 independent rcbo
Fault finding will be easier if done correctly

rx8

Thanks for the replies anyway, I'm going to have to get a sparks up to have a gander at it and try to resolve it somehow.

meercat

rx8 wrote: »

Thanks for the replies anyway, I'm going to have to get a sparks up to have a gander at it and try to resolve it somehow.

Fitting 2 new rcbo and an insulation resistance test should resolve/identify your issues.
Don’t forget to get a certificate and also a copy of your test results from him.

Malcomex

newuser555555 wrote: »

why is it that all garo boards look incredibly cheap

They're a sh1t brand

Wouldn't surprise me if they were French , they have a weird setup where they're halfway down sometimes

Risteard81

Malcomex wrote: »

An IR test of the installation will prob show up low readings i'd expect

If not you could try swopping out the RCD


Do car chargers connect to the main RCD. I would have thought they would be independent of it?

I'm not familiar with them though

Every EVSE (Electric Vehicle Supply Equipment), i.e. chargepoint must be protected by its own dedicated RCD which breaks all live conductors. This RCD cannot be shared with any other circuits or equipment, or with any other EVSEs. This must be a Type B RCD unless 6mA DC leakage protection is incorporated into the EVSE, in which case it can be a Type A RCD.

Risteard81

Malcomex wrote: »

Shouldn't an inverter be separate as well ?

Yes it should, as it could be supplying the installation for a number of seconds after the RCD operates before shutting down due to loss of power. This defeats the requirement of the RCD to operate within 40mS at 5 I delta n. Also there is a strong chance that the RCD is of the wrong type - can't see clearly but it might be a Type AC RCD.

Risteard81

Malcomex wrote: »

I thought they required an AC or even a B type Rcbo could be totally wrong there

They must not be Type AC as DC leakage components could "blind" or saturate the RCD, preventing it from operating (or operating within the required time).

Risteard81

Malcomex wrote: »

They're a sh1t brand

Wouldn't surprise me if they were French , they have a weird setup where they're halfway down sometimes

Garo are Swedish (although they have a factory in Dublin I believe).