RCD randomly tripping, replacing with RCBO's?

I've got an old cartridge type consumer unit and the built in RCD trips, fairly randomly.
I think its something to do with moisture in the air, tends to happen during wet periods, but it happened during the dry cold period as well last winter.

Anyway.
Since I cant really afford to have the problem properly sorted, which would in my understanding basicaly requires a rewire, its my understanding that the unit wide RCD, can be replaced with circuit wide RCBOs, so that should the fault occur again, it will only disable the effected circuit, allowing the rest of my house to continue unaffected.

Is anything I've just said even close to being accurate? And if so, is it a proper electricians job?

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When I say randomly, I really do mean that, hasnt happened for at least three months, one day last winter, it went ever couple of minutes, then, with nothing unplugged or changed in anyway, it ran fine for days or weeks.
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A good start would be to get a PIR (Periodic Inspection Report) carried out by an electrician, this should hopefully help pinpoint the problematic circuit.
It is always better to sort the problem rather than try to work around it.

I agree with spark123. In fact, an insulation test might identify the problem within minutes and cost a fraction of installing RCBOs.


I see why you would want to switch to RCBOs to reduce the tripping to just one circuit and perhaps in doing so identify the culprit circuit. But what if this is not a single fault but an accumulation of poor insulation resistance on multiple circuits? In such a case the RCBOs will only be a short term fix since insulation resistance usually get worse over time.

If the whole installation is protected and it seems to happen in wet / cold weather perhaps it could be an outside light or socket causing the problem? Sometimes a build up of water in the casing will cause an RCD to trip. In any case as long as you have twin and earth PVC wiring I doubt if you would need a re-wire unless the wiring is very old.

A PIR would be the way to go, a realistic cost is about £20 per circuit and an electrican can advise about a replacement consumer unit.

Would need to see picture of your fuseboard, but I will bet that if cannot support RCBOs.
The only real solution is to have problem analysed. "damp air" won't cause an RCD to trip, damp or faulty wiring, or a faulty appliance is the more likely suspect.

But what if this is not a single fault but an accumulation of poor insulation resistance on multiple circuits?

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I thought that my one RCD will be tripping at a combined level of 30, somethings, but if I instead had four individual RCBOs, then each circuit can have 10 somethings and everything will run fine?

Would need to see picture of your fuseboard, but I will bet that if cannot support RCBOs.

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Damn, I'd just assumed they made RCBOs in the form Id need, but a quick google hasnt found any.

So could anyone guess a ball park figure if I need a PIR, New CU and 4 RCBOs?
£200?
£300?
£500?

It can only be determined after seeing the site. Find three competent and registered electricians and get quotes.