Ring Final Circuits (OK I don`t think that Flameport likes them!)

[EFLImpudence]

You were.

Hmmm let's design a circuit, a 32A sockets radial requiring 100m of cable in a domestic property.

 

[SUNRAY]

You were.

However silly you may think it is, such a circuit may be installed as a ring a heck of a lot cheaper than a radial.

 

[ebee]

well you might be lucky and not have an overload or short circuit or an earth fault on either of those two radials inadvertently occurring from a malfunctioning ring final circuit. It is not impossible but I would not suggest relying on it. Actually an earth fault or short circuit you may well get away with it if we consider only dead shorts rather than higher impedance possible real world scenarios. The biggest challenge is managing possible overloads

 

[JohnW2]

You do minimise inconvenience if something goes wrong. Yes, I know some of you have said it's a once in a blue moon scenario,

That's because it is

but then many of us would agree insurance cover for a breakdown for example would save a load of hassle. You may not need it but when you do, it will save you inconvenience and potentially money too.

I'm not totally sure how to interpret that, but I personally would not insure against a 'once in a blue moon' risk, unless the magnitude of the risk (like 'a house burning down') if it ever happened, would be far too big to 'bear' oneself (or unless I was legally required to insure).

In any circumstances, the cost of insurance premiums has got to be greater than the expected/'average' cost if policyholders bore the risk themselves (otherwise the insurers would not be able to pay they staff or overhead bills, let alone make profit!) - but, as above, some potential losses (e.g. of houses) are far too big for most people to be able to 'bear themselves'.

Kind Regards, John

 

[securespark]

Some people in certain situations may want to minimise the inconvenience of a trip causing a freezer thaw. So, instead of having the freezer on a ring final protected by an RCD along with other circuits, you may want a dedicated freezer radial on an RCBO.

 

[JohnW2]

Some people in certain situations may want to minimise the inconvenience of a trip causing a freezer thaw.

They do.

So, instead of having the freezer on a ring final protected by an RCD along with other circuits, you may want a dedicated freezer radial on an RCBO.

That's obviously an option but, as I always say, if you do that you really MUST also have a (battery-operated) over-temp alarm on the freezer - since loss of power to a freezer on a dedicated circuit can go undetected/un-noticed for a long time - if it's on the same circuit as the TV, it won't go unnoticed for long (when the house is occupied)!!. Even an alarm doesn't help if the house is unoccupied, but one can't do anything about that (and I agree that the chances of it losing its power are then greater if its on a dedicated circuit.

As I've said before, on the couple of occasions I've experienced an RCD to trip and de-energise the circuit the freezer was on, the trip has been due to a fault in the freezer, so the same would have happened regardless of what circuit it was on - and, similarly, when I have 'lost freezers', it's been due to a fault in the freezer, not a loss of power (although, as above, in a couple of cases the freezer fault has tripped an RCD.

One other thing about 'splitting into multiple circuits' (the ultimate being 'all-RCBOs') is that, for those people (not me!) who seem to experience fairly frequent random and never-explained 'nuisance trips' of RCDs, if it really is 'random', then the more devices there are, the more nuisance trips one is likely to get! ... although I agree that trips due to addition o multiple leakage currents (also something I've never knowingly experienced) will be less likely with 'split circuits'.

Kind Regards, John