Crabtree 80A RCCB 30MA Trip Consumer Unit, circa 1987.

[ragsusu]

This unit(Earth rod outside) keeps tripping whenever there is a thunder clap. Alright if we're at home but on holiday the freezer & fridge stay off until unit is manually reset. Consequently - ruined food, etc. 3 local electricians do not seem to know the answer other than expensive replacement..
Can anyone please advise?

[raysparx1]

Does the Rccd cut everything off ? or just the sockets ?

[ragsusu]

Thanks for helping out.
Everything is cut off, lights & power, when there is a nearby thunderstorm. My idea was to fit another small consumer unit that didn't have this cut off device or at least not such a sensitive one & wire it into a convenient new socket just to feed the freezer & fridge whilst we were away, but since it would be connected to the mains coming into the house I don't feel I should or could do it.
Any suggestions?

[raysparx1]

Hi it depends on the wiring system coming into the house,
if it is what is known as a TT system everything MUST be covered by an Rccd if it is a TN-S or TN-C-S system you could put a seperate unit in just for the Freezer,

if you look at where the supply comes into the house, is there an earth wire coming out of where the incoming supply is ? can you check this, I will look on later, Ray

[Catso]

Ray's the techie, but I will add that a few years ago, our RCCB started tripping, at little provocation. It got more and more frequent; in the end we just had it replaced, and the problem went away.

So they can break/wear out.

[ragsusu]

Thanks Catso.
I hope it doesn't come to that as Crabtree say they no longer make the Consumer Unit.

Hi Ray,
Checked the meter box - single thick black wire going to meter via a PME System box (protective multiple earthing). This seems to be attached to a 60 amp fuse with a lead seal on it. A similar thick wire then goes into meter.
There is an earthing wire going into the ground beneath this meter box but I can't see any sign of it in the meter box itself. I thought that it may come from the Consumer Unit in the house, but I don't really know

[raysparx1]

where the main 60 amp fuse is, does an earth wire come out of that into the consumer unit ? it will either come out of the top or from a little brass section at the side of the main fuse. can you check that.

[raysparx1]

Thinking about this if you are on a PME system, I would think you would be okay to have a seperate circuit installed purely for the fridge/freezer, it would mean a seperate unit with a 16 amp mcb, and spur units put in for the appliances, but an electrician would have to do this under new building regs, but as I said if it is a TT system it has to covered by an Rccd, call out a local sparky and get him toi see if it is this type of system, I wouldn't think it should cost a fortune if its possible to put a one way unit in.

[ragsusu]

The only wire coming out of the 60 amp fuse is a thick black wire going into meter.

[raysparx1]

you are going to have to find out which system it is, I hope it isn't TT cos if it is it will mean a new Rccd, you may be able to just get that part changed not the whole unit.

is there a brass block at the side of main fuse or at the top of it ?

[ragsusu]

I also hope it's not a TT system, but if it is, Crabtree say the Consumer Unit is old hat which means a new unit & someone to fit it. 3 electricians in this area don't seem interested & that is why I'm on this site for advise.
As regards the brass block there doesn't appear to be any metal only plastic on PME & fuse box.
Is there any way that I can tell which system I'm on - TT or the others by just looking?

[raysparx1]

it sounds like it is a TT system, on the other systems an Earth wire comes out of the cut-out (main fuse) either directly or or from a block at the side a TT system has an earth wire from the Consumer unit to the earth rod, one thing you could try to improve earthing is pour a couple of buckets of water over the top of earth rod,

it is an easy job to have unit changed, why aren't they interested, that is mad, if I were you I would go to the "Napit" web site, type in the postcode you live and that will bring up local electricians in your area, good luck, Ray

[ragsusu]

Thanks Ray for all your advice.
I'll try the bucket of water as you suggest but it looks more like a replacement will have to be done.
Thanks again.