rcd overloaded????

redmaurader

just finished building a house and moved in and the electrician has finishing up the electrics, well almost, he has fitted a RCD with 30mA sensitivity to the consumer board, the rcd serves 30 double sockets, oil fired burner its pump and stat, stove with its own pump and stat, fridge, freezer and dishwasher. It may also serve lights but i dont know to be honest if lights are supposed to be protected by a rcd
I think that its too much for a single rcd with 30ma sensitivity and should have at least 100ma sensitivity for a single rcd, the electrician says that this shouldn't be done as it doesn't give proper shock protection, so fair enough i say split the lot into 2 or 3 seperate rcds, one for plugs one for two heating systems and one for kitchen appliances, electrician sighs shakes his head and walks off, i'm left standing bemused.
so a couple of time now when we have pressed the switch on a plug to switch something on the power goes off and the rcd has tripped, once we were all sitting in the living room noting extra was switched on and the rcd trips, i've been on to the electrician and he says that its not due to the overload on the rcd that its most likely to be the exposed wires outside for the external lights (thats why i said almost finished)(also why i query are lights protected by rcd) Anyways there is a bit of tension between myself and the sparky for what reason i dont know other than me questioning him and hes stopped answering my calls.
So guys anyone got any suggestions, is the 30ma rcd overloaded, should i replace it with a 100ma, should i get a different spark in to finish off the job and spit the lot into 3 rcds can this be done easily and cheaply?

all advice greatly appreciated and thanks for taking the time to read this

Stoner

lights should not be on the same RCD as sockets, and at the moment you don't need an RCD for lights, if something trips you want the lights on. Most houses only have on RCD and this does not feed the lights.

Adding a second RCD to your board and splitting the circuits is the best option IMO .
what the electrician has provided for you is the norm, we cant tell from here if there are too many items on the RCD, what you have listed is nothing out of the ordinary. Security lights being turned off by a tripping RCD in not a H&S issue.

After sep this year an RCD or RCBO will be required for lights in toilets/bathroom with ceilings below 2.25M

redmaurader

is it possible to add another rcd to the fuse board and split the circuits or does it need a whole new fuse board, if it is possible is this an expensive job

Stoner

depends on the size of the board and if you need it.

How many rows on the board? maybe an RCBO (combined RCD and MCB) would be better for the heavy circuit in your kitchen.

But the electrician may have given you the correct advice, it could very well be the outside light, working on the board is a job for a pro though.

davelerave

Extra rcds or rcbos can be fitted to minimize nuisance . but they have to be rated at 30ma because of shock risk overload is not an issue

Randyleprechaun

Your spark is right...has to be 30ma RCD and i dont think from what you have said that it is overloaded. New rules will force outsdide lighting to be on RCD anyway.

Stoner

I've a couple of RCBOs on my board along with the RCD. I've one for the heavy kitchen circuit (most likely to trip) and I have one for all my computer equipment (can't have this falling over just because someone over fills the iron), these are the only reasons I have for adding additional RCD protection it's handy not having to reset the clocks and put the code into the alarm every time there is a trip in the kitchen. Nothing really trips that much though.

aws

The RCD is prob rated at 63A so very unlikely its overloaded. More like wire exposed for outside socket, or water pump or even sewege treatment plant. Could be damaged cable either in attic...

bertie1

redmaurader wrote: »

is it possible to add another rcd to the fuse board and split the circuits or does it need a whole new fuse board, if it is possible is this an expensive job

I have no doubt if you were willing to pay the electrician for extra rcds & his time (provided there is space in the board now for the extras) he would be happy to oblige but in order to add them in now it requires seperate neutral bars in the board for the different rcds, they will still need to be 30mA and not 100mA as you suggested. The electrican needs to comply with the regulations . The cost is the rcds electricans time & the extra neutral bars

The loads listed suggest a standard house so the extras you are now looking for would not be the norm.

The outside light cables that are not fininshed just need to have the neutrals & earths seperated until you are actually fininshed as every wet night could trip them at the board

Cheeble

IMO the RCD is tripping for a reason; it's almost certainly nothing to do with being overloaded.

You need to find out what this reason is, and fix it before it kills somebody.

Cheeble-eers

Offy

If the RCD keeps tripping there is a problem. A RCD monitors the current flowing in the live and neutral wires of a circuit. If one of the lines is grounded the current differs in the two lines and the RCD trips. If its a human touching a live of neutral wire when it trips then the RCD is functioning correctly. If i live or neutral wire outside the house is grounding of something then the RCD should trip.
RCD sometimes suffer from nuisance tripping, this is caused by a faulty RCD of a faulty circuit. Replacing the RCD might help. The electrician has specified the correct RCD, I wouldnt change its rating.
Id say the exposed wires outside are the main suspect but it could also be a loose wire in a socket of switch somewhere.

redmaurader

have gone round all the sockets checked the wires weren't loose or no plaster droppings making earth contact, have taped up the exposed wires outsidewith insulating tape for now until i can get spark back or another one in to replace, went to fit a light fitting myself at the weekend switched it on and nothing, checked in attic and the wires are lying loose not connected into circuit so it probably isn't the external lights, only other electrics outside is a switch outside for the oil burner, this is located on the outside wall on under an external staircase in a standard internal fitting should this be a weather proof switch? checked inside it but couldn't detect any moisture, but dry conditions over the weekend so maybe i'll check again next time it trips.
bought one of those plug in testers from homebase i know they probably aint great but it found no faults in any socket, which only leaves the socket for fridge, freezer & dishwasher which are under counter behind the appliance and controlled on an isolater, have noticed the trips are mainly in the games room when something is switched on but not always.
will let you know how i get on

fishdog

If the RCD keeps tripping there is a problem

Exactly.
This should be an easy problem for any competent electrician to fix. An insulation resistance test (meggar test) will show where the problem is quite quickly. An RCD tester may come in handy too, just in case the RCD is faulty.

Offy

What make is the RCD, I design RCD's so with the make I might be able to tell you more about the problem.

redmaurader

Offy wrote: »

What make is the RCD, I design RCD's so with the make I might be able to tell you more about the problem.

nearly certain its a Hager rcd but not 100%, its either hager on a garo board or garo on a hager board, i'll check this evening when i get home

fishdog

nearly certain its a Hager rcd but not 100%, its either hager on a garo board or garo on a hager board, i'll check this evening when i get home

It does not really matter. RCDs are not a servicable item. If it is faulty you must replace it, end of story. An RCD tester will tell you in minutes if it is faulty or not. Your electrician will have an RCD tester.

redmaurader

Offy wrote: »

What make is the RCD, I design RCD's so with the make I might be able to tell you more about the problem.

its a garo rcd

Offy

I'll check them out tomorrow in work. Not one I ever worked on thank god

scarpetta

Best advice I can give you is to protect each socket cct. with it's own dedicated, correctly sized RCBO, thus providing both shock and overload protection for each cct. No more nuisance tripping of all your sockets - faults are automatically isolated to problem circuit. Consumer unit should be easily reconfigurable to allow for this unless you've got a small or crowded one.

paddymick

you havent said what rating the rcd is.is it 40A or 63A alot of boards used to come with a 40A as standard especially single row boards because if its a 40A you could very well be overloading it if its a 63A i think its very unlikely your overloading think about it if you are overloading a 63A rcd that combined with all the stuff not on the rcd dont you think the main fuse would blow which is also rated at 63A.So paying someone to fit and extra couple of rcd`s is a total waste of money.
Also is the board more than a couple of years old because there was lots of problems with Garo RCD`s a few years ago,

At the end of it all RCD problems are not for the DIY electrician theres just to many factors that can be wrong and you need the proper gear to find faults,
Get an electrician to do a quick rcd triping test and an insulation resistance test on the out door stuff any obvious faults will show up straight away.

Anyway good luck.