Plug socket lost power.

grumbler

The easiest way to check is trial and error. Plug a switched on lamp into a socket and check which MCB switches it off. If your fridge has a light inside, no need to use a lamp.

For each socket (or a group of sockets - ring) it can be only one MCB.

tony3619

macman said:

Rather weird to run separate radial circuits for a kitchen just to put a fridge/freezer and hob on it? Is this a very large kitchen with lots of 13A sockets installed?
By contrast, the entire 1st and 2nd floors are on a single ring circuit...

Definitely not a large kitchen. It only has a washing machine, hob, cooker and fridge. All controlled by that fuse panel on the kitchen wall. 

What's also strange is I dont have a stair lift! 

Section62

grumbler said:

For each socket (or a group of sockets - ring) it can be only one MCB.

At the risk of being accused of the 'P' word, the "can" ought to be read as "should".

People have been known to do some very odd things, and if the installation is not properly tested, and both MCB's are on the same RCD, then a ring (or unintentional ring) which started on one MCB and finished on a different one, woudn't necessarily reveal itself in the tripping of anything, unless one of the MCB's had a much lower rating.

The situation could happen quite easily - for example if someone thought two radials were supposed to be connected and installed a link between them.

Proper testing of the installation should pick this up before any harm was done... but not everyone does proper testing when they make wiring alterations.

grumbler

Section62 said:

grumbler said:

For each socket (or a group of sockets - ring) it can be only one MCB.

At the risk of being accused of the 'P' word, the "can" ought to be read as "should".

Yes, I wanted to edit my post to the same effect, but decided not to.

tony3619

Section62 said:

grumbler said:

For each socket (or a group of sockets - ring) it can be only one MCB.

At the risk of being accused of the 'P' word, the "can" ought to be read as "should".

People have been known to do some very odd things, and if the installation is not properly tested, and both MCB's are on the same RCD, then a ring (or unintentional ring) which started on one MCB and finished on a different one, woudn't necessarily reveal itself in the tripping of anything, unless one of the MCB's had a much lower rating.

The situation could happen quite easily - for example if someone thought two radials were supposed to be connected and installed a link between them.

Proper testing of the installation should pick this up before any harm was done... but not everyone does proper testing when they make wiring alterations.

Well it was a new build 4 years ago and judging by the rest of the problems I've had it's probably a bodge Job on the electrics aswell. 

What I can confirm is that a loose wire on the washing machine and a water spill on the hob have both tripped the kitchen MCB over the last 4 years. 

Risteard

macman said:

Rather weird to run separate radial circuits for a kitchen just to put a fridge/freezer and hob on it? Is this a very large kitchen with lots of 13A sockets installed?
By contrast, the entire 1st and 2nd floors are on a single ring circuit...

Not strange at all. In fact the Irish Wiring Rules require it so that a fault elsewhere doesn't cause loss of food in a freezer. However with your setup on a shared RCCB this isn't actually achieved in an Earth fault scenario.

FFHillbilly

I don't think it's weird either, The more divided circuits are the less disruption is cause in the event of a fault.
the price of the materials seems to have come down, in contrast to everything else for example a 6 way fuse box in the 80's was 1 months wages, now a 15 way consumer unit with RCBO's costs a weeks wages. so it makes prefect sense to divide everything up. in America they have circuits for every room. some houses over here still have 4 circuits

tony3619

grumbler said:

Section62 said:

grumbler said:

For each socket (or a group of sockets - ring) it can be only one MCB.

At the risk of being accused of the 'P' word, the "can" ought to be read as "should".

Yes, I wanted to edit my post to the same effect, but decided not to.

so I had an electrician round who checked the fuse board and the socket and found no problems. 

The fridge worked fine for the last 7 months and randomly switched off last night.  

In order this is what happened when I tried to switch it back on ...... 

I open the fridge and no light is on + it's warm

I tried others appliances in the same socket, nothing works. Other sockets are fine.

I try to switch the fridge off and on at the FCU panel and try to change the fuse. Nothing helps

I turned off the main power and it trips one of the two RCDS. I turn on the power and try to reset the RCD which produces a bang/ popping noise (from somewhere in the kitchen) and the RCD trips again.

I turned off the fridge at the FCU and turned on the mains power and reset the RCD and this time it stays on. I turn the fridge back on at the FCU and the fridge has come back to life.

I have an electrician booked to come back but am concerned about the bang noise and the fact only one outlet continues to cut off. The only common dominator is my oven light also cut out the same as the first time (the oven still worked) 

Sorry I posted a new thread. Forgot I had this one open.

Any clue??

Jonboy_1984

tony3619 said:

I find it baffling that turning the trip switch on and off would make it work again even though it didn't trip in the first place. 

We had a rcd on a lighting circuit at work that tripped regularly, and it didn’t consistently move the switch when it did, so we had to toggle it off and on to reset. 

Last circuit I had that made a popping noise had a loose wire in the back of the socket (they can vibrate and work looser over time, particularly if used with a high energy appliance).

tony3619

Jonboy_1984 said:

tony3619 said:

I find it baffling that turning the trip switch on and off would make it work again even though it didn't trip in the first place. 

We had a rcd on a lighting circuit at work that tripped regularly, and it didn’t consistently move the switch when it did, so we had to toggle it off and on to reset. 

Last circuit I had that made a popping noise had a loose wire in the back of the socket (they can vibrate and work looser over time, particularly if used with a high energy appliance).

Did the socket still work after the popping? Or did it keep tripping?