Ring main problem

[jammy75]

Hi, I woke this morning to find no power to sockets, boiler and cooker in the house as the RCD on a split board had tripped, I flicked off all the MCB's, turned off all switches on plug sockets and started flicking the MCB's back on, cooker, boiler, first floor ring main and grd floor ring main all came back on fine, as soon as I flicked on the kitchen ring main MCB the RCD tripped. As I've unplugged all appliances and switched off the sockets in the kitchen could it be a faulty socket causing the trip?
Thanks,
Jammy

 

[HERTS P&D]

Normally the fault is with the: washing machine, tumble dryer or iron.

But if everything is unplugged and still tripping then it can be a socket.

Wait for one of the sparks to wake up, they can help you a bit more.

Andy

 

[securespark]

Possibly.

Have you made absolutely certain you have disconnected EVERYTHING?

DP switches need turning off. Hood, electric hob, oven, DW, WM, TD, fridge, freezer, microwave, kettle, toaster, gas hob, anything fed from the kitchen to outside, check every nook and cranny!

If you have disconnected everything & it still trips, you will need some test gear to proceed, or pick the circuit to bits and reconnect it leg by leg...

PS I was awake at 0630....

 

[jammy75]

Thanks for quick reply fella's, the switches on the sockets are all off and there's no electrics outside. I'm thinking of getting some 15amp terminal blocks, taking off all the kitchen sockets and fitting the terminal blocks so the ring main is a complete circuit and flip the MCB if the RCD goes again I know its something I need to get a spark to have a look.

 

[pjcomp]

Have you got a gas hob? The sparker is usually plugged in to something hidden in a cupboard or even behind the oven, and when you're looking for an electrical fault it's easy to overlook a gas appliance ... And yes, it can sometimes be a socket that goes rogue and causes the tripping.

pj

 

[Chri5]

Just to elaborate on an earlier post, kitchen circuits tend to have fixed appliances, via fused spurs mostly.

So do double check, there's not point in pulling things apart until you have isolated all potential problems. Washer, tumble drier, dish washer maybe supplied via obscure / hidden sockets and fused spurs behind the appliance.

 

[TicklyT]

Your fridge and freezer should feature in the list of 'usual suspects'.
Frost free ones usually have a tray to catch melt water from their defrost cycle mounted on top of the motor.

The theory is the heat from the motor evaporates the melt water, but sometimes the tray overflows...

 

[Taylortwocities]

Boiler/central heating system is the number one suspect in my experience.

Plus I'll bet you have a socket or two in/under kitchen cupboards that you have forgotten/do not know about.

 

[securespark]

Ha! Forgot boiler on my list...

Sockets being switched off is not enough. You may have SP switches in which case the neutral will still be connected.

 

[GarethW]

...the switches on the sockets are all off...

You need to physically remove the plug from the socket in case your sockets are only single pole,
otherwise, a neutral to earth fault on an appliance would still make the RCD trip.

 

[securespark]

Ha! Forgot boiler on my list...

Sockets being switched off is not enough. You may have SP switches in which case the neutral will still be connected.

 

[GarethW]

My bad, didn't refresh

 

[JohnW2]

Sockets being switched off is not enough. You may have SP switches in which case the neutral will still be connected.

You need to physically remove the plug from the socket in case your sockets are only single pole,
otherwise, a neutral to earth fault on an appliance would still make the RCD trip.

In the situation described, I doubt that is an issue. The OP has told us that switching off the (presumably SP) MCB for the kitchen circuit prevents the RCD tripping. As far as I can see, only if (I would say unlikely) there were absolutely no loads on other circuits protected by that RCD (AND there were some load still connected to the kitchen circuit) would that be the case with a N-E fault on the kitchen circuit - otherwise the RCD would operate, even if the kitchen MCB were 'off'.

Kind Regards, John.

 

[ljarrald]

...the switches on the sockets are all off...

You need to physically remove the plug from the socket in case your sockets are only single pole,
otherwise, a neutral to earth fault on an appliance would still make the RCD trip.

Ha! Forgot boiler on my list...

Sockets being switched off is not enough. You may have SP switches in which case the neutral will still be connected.

doesn't matter, it won't be a N-E fault because if it was then the RCBO would trip even if the kitchen circuit was off.

 

[ljarrald]

just seen JohnW"'s post which i replicated, sorry about that.