Intermittently tripping RCD

[everyonelovescheese]

Hi All

Our house has been plagued with a problem for a while, we have had 2 electricians come and visit who have not been able to track the issue down.

The issue we have is that the RCD trips randomly. This month it has done it 3 times, twice early in the morning, and once during the day. Before this occurrence it hadn't happened for a couple of months.

British gas home care came out and ran a ramp up test on the RCD and it passed without problems. We have no external power sockets or light fittings and I am unable to make it trip at will.

When it does trip, I can reset the breaker 90% of the time without issues, the other 10% of the time it springs back down again and I have to wait a while before I can reset it again.

I run a business from home and have a fair amount of servers running 24x7. These are run from 2 separate UPS's (which have been replaced to rule them out), as such this is driving me crazy!

Any ideas? (pic of RCD attached)

 

[EFLImpudence]

The RCD is simply doing its job.

You have all the sockets in the house on one RCD.

The 'problem' sounds like an accumulation of earth leakage - particularly with your equipment.

I don't know what the electricians found or decided but if they found no actual faults it could probably be overcome by installing one or more RCBOs to separate the circuits.

Did no one suggest this?

 

[flameport]

I run a business from home and have a fair amount of servers running 24x7. These are run from 2 separate UPS's (which have been replaced to rule them out), as such this is driving me crazy!

How many exactly?
What type of UPS?

 

[plugwash]

Personally I would suggest putting the servers on their own non-rcd circuit. Large ammounts of computer equipment can get fairly leaky as it ages and there is really no need for it to be RCD protected.

You seem to already have a spare 32A breaker on the non-RCD side so this should be a relatively simple job.

 

[everyonelovescheese]

I run a business from home and have a fair amount of servers running 24x7. These are run from 2 separate UPS's (which have been replaced to rule them out), as such this is driving me crazy!

How many exactly?
What type of UPS?

8 - 2 smart ups 2200

 

[everyonelovescheese]

The RCD is simply doing its job.

You have all the sockets in the house on one RCD.

The 'problem' sounds like an accumulation of earth leakage - particularly with your equipment.

I don't know what the electricians found or decided but if they found no actual faults it could probably be overcome by installing one or more RCBOs to separate the circuits.

Did no one suggest this?

Hm, nobody has suggested that before, I assume to do this I would need a larger board as there would be no space left?

 

[everyonelovescheese]

Personally I would suggest putting the servers on their own non-rcd circuit. Large ammounts of computer equipment can get fairly leaky as it ages and there is really no need for it to be RCD protected.

You seem to already have a spare 32A breaker on the non-RCD side so this should be a relatively simple job.

I will double check to see if that is actually SPARE, I don't trust the people who labeled it in the first place.

Any idea how much it would be to run another circuit from that breaker cost wise (approximately of course)

 

[timtheenchanter]

even if its not spare, there is a spare (as in unoccupied) space on the non RCD side there, so you could fit another MCB. (then it would be full)

 

[everyonelovescheese]

even if its not spare, there is a spare (as in unoccupied) space on the non RCD side there, so you could fit another MCB. (then it would be full)

Ah yes I see what you mean. Sounds expensive either way.

 

[davidgreene]

Get a new consumer unit fitted, split your socket circuits up for a start, it's gonna be a problem in the kitchen i'd bet

 

[sparkwright]

Get a new consumer unit fitted, split your socket circuits up for a start, it's gonna be a problem in the kitchen i'd bet

What sort of answer is that?

Last night you announced to all and sundry that you're not too hot with RCBOs.

Why do you say the kitchen?

Though expensive, fitting a new consumer unit with individual RCBOs would of course help to pinpoint which circuit the 'fault' is on, and would prevent all the socket circuits going down together. You may even be able to adapt the old cu to accomodate the RCBOs.

 

[martinxxxxxx]

Hi

I think the that the amount of computing equipment is the main factor here. I hope you did not pay those electricians for not sorting out the problem. PAT testing the computing equipment would allow you to see exactly how much leakage is occurring.
I agree with the idea of putting them on their own circuit, but this does need to be done by a competent electrician; who is able to reconise if an RCBO is necessary for the circuit (it probably is) , if so then you would have 30 whole milliamps of leakage available for just the computing equipment. Don't listen to David Green he takes a bath with his laptop while it is plugged in . PAT testing which could be done by the electrician at the same time would determine if this would be enough and solve the problem.

Good luck

 

[EFLImpudence]

British gas home care came out and ran a ramp up test on the RCD and it passed without problems.

In case you do not know -

The ramp test determines at what residual current the device trips.
Although they are marked 30mA, this is the maximum at which it must trip.
It could be anywhere between 16 and 30 - usually 25 - 27 or so.

Did they tell you what the value was?
Did they test each (socket) circuit individually?

Did they offer any remedy?

 

[everyonelovescheese]

Sorry for the delay on this, I didn't see the update!

I wasn't given any information by the British gas engineers unfortunately

I don't believe they tested each socket individually (I wasn't at home watching them).

He essentially said he will replace the RCD and would come back if it happens again.

I think im going to go down the route of a new ring circuit for the Servers.