We cannot work out what has caused the fusebox to trip out.

[BorderReiver12]

I was working at the computer tonight when it suddenly went off, as did all upstairs sockets and downstairs lights. One of the main switches in the fusebox (is it still called that?) had tripped. I pushed it back up without any problem and so far it's been OK after an hour.
We had our whole house rewired and a new fusebox installed about a year ago.
The central heating system (pump) developed a fault recently which kept tripping the same switch in the fusebox, but we've had a new pump installed on Saturday and all has been well.
The areas covered by that switch are...upstairs sockets, downstairs lights, kitchen and office sockets (downstairs) and central heating + immersion heater. We don't use the immersion heater at all, so when the system tripped, there was only one light, one computer, heating and fridge in operation. The heating system wasn't at any stage where it was doing anything...pump not operating and timer or thermostat not switching anything off or on, so there was little demand on the system.
Has anyone any suggestions as to what the problem might be and if it's likely to happen again...or is it one of those things that sometimes happens?

 

[conny]

I'm not a spark so can't give a definitive answer, however, there have been a number of similar posts which suggest the fridge/freezer may play a part in this scenario.
Keep checking the replies because I am sure you will get the help you need.

 

[ericmark]

All RCD's are not equal and the cheaper ones can trip due to electric storms or spikes caused by switch mode power supplies such as those used by computers.

So likely this is normal and will happen from time to time. There are items like the freezer which switches on the de-frost element at odd times and can be really hard to pin point but more likely just a spike on the line.

The more the circuits are split the less likely they are to trip so using RCBO's instead of just 2 RCD's will likely reduce the problem. However the problem is then realising when something has tripped.

There are also more expensive RCD's like the X-Pole click here to read more there are even auto resetting RCD's like this

Untitled

• ericmark
• 6 Dec 2008
• 34

but the cost is really high around £350 just for the RCD in the picture.

You get what you pay for and most people don't want the extra expense of RCBO's and consider to have to reset it every now and again is worth the money saved.

 

[crystal ball]

Had a problem with a fridge freezer (suspected) tripping an RCD, changed from a Proteus (cheap) to Merlin Gerin (more expensive) and the problem went away

 

[PrenticeBoyofDerry]

Has anyone any suggestions as to what the problem might be and if it's likely to happen again...or is it one of those things that sometimes happens?

RCD trips do happen out of the blue and once reset there is no continuation of the RCD tripping again.
But if it does do, monitor the actions taking place in the house at the time of the trips and what appliances are in use. If the RCD continuously trips, the best method of investigation is to remove appliances and reinstate them one at a time and see what is causing the problem. Could be that two appliances(or more) , build up enough leakage to cause the problem.

 

[BorderReiver12]

Thanks for the replies everybody.
We have a brand new Volex VR80 with 2 main switches + 2 secondary switches, each covering 4 other switches + a seperate shower switch. Everything has been fine since last night and as it didn't trip out immediately when I reset it then, I'm going to go with the theory that it's just a one-off. The worst that can happen is that the fridge and heating goes off & we're getting a new heating system in soon anyway. House alarm is covered by the other switch.

 

[BorderReiver12]

The system tripped out again tonight - a couple of hours earlier than last night, so I switched off the four minor switches covered by the one that tripped, then switched that main one on, followed by the other four, one at a time ...and when I switched the heating system trip switch back on, it tripped out the main one. I then tried adjusting the Tempus 7 central heating control and when changing it from twice to off, it tripped out at the fuse box. It's an ancient control box and it's just as well we're putting in a new combi, rads and pipework soon. I'm trying to get around the problem for now by putting the heating on constant and just controlling it with the thermostat alone - turning the heating up or down using it, doesn't trip any switches in the fusebox.... I hope.

 

[EFLImpudence]

Well done. You seem to have found the area of the fault.

You could put in a new programmer as you will need one soon anyway although it could be a zone valve or something else, depending on the type of system.

These faults are very difficult to find.