Why does the UK use rings for sockets?

[pc1966]

I prefer radials protected by RCBOs and would welcome DP ones if they could get them in a single module.

If you are happy with Wylex or Crabtree they do single module RCBO for domestic boards with DP switching.

 

[Mike Johnson]

The problem is they are not true double pole switching in a single module, only the double module units have double pole switching, its the physical size of the internals that dictate the width of the module two contacts at a distance of 3mm width can't fit in a single module.

 

[Ian1981]

The problem is they are not true double pole switching in a single module, only the double module units have double pole switching, its the physical size of the internals that dictate the width of the module two contacts at a distance of 3mm width can't fit in a single module.

How can they claim to be DP but are not?
Is it not 3mm between contacts?

 

[Mike Johnson]

Because they do not provide a 3mm air gap when triggered on both, look at the side of any of the modules and you will see the circuit diagram.

 

[Mike Johnson]

How long before we have ARC also combined into a RCBO, perhaps called an ARRCBO or Arc Bo for short?

 

[Ian1981]

How long before we have ARC also combined into a RCBO, perhaps called an ARRCBO or Arc Bo for short?

We already do, wylex/ Crabtree do them.

 

[Mike Johnson]

I'v obviously lead a sheltered life, especially over the last four weeks, cost seem a bit prohibitive, but then if you take into account the three modules it replaces, perhaps not that expensive, thanks for that.
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Anyone found one without the flying lead?

Also is anyone able to confirm that they are truly dual pole and break the connection by 3mm on both the phase and neutral? Been looking for a wiring diagram, but without success so far on any of the specification sheets.

 

[pc1966]

Wylex are pretty rubbish in the documentation area, but most companies are these days. I doubt you will easily find one without a flying lead though, as virtually all UK domestic CU only have provision for a live bus-bar, and not neutral.

You can get the Wylex single module RCBO for around £25 so worst case you buy one to sacrifice and see what is inside it!

 

[Ian1981]

Schneider isobar p range have no flying leads and plug into the DB.
TPN set up tho so for non domestic really

 

[Mike Johnson]

I doubt that Wylex do anything more than Hager's RCBO who I have already investigated and found they are not true dual pole in the UK in single module width, but in dual module width in the rest of Europe they are true dual pole, I have come to the conclusion that you can't get true separation of 3mm on each pole without the extra width, which seems logical when you consider the doubling up of the number of mechanical components needed, obviously flying leads are not required.

All of the above makes me suspect that the current ARC/RCBO offerings with the flying leads are not true dual pole either, but it is only a suspicion.

 

[pc1966]

I'v obviously lead a sheltered life, especially over the last four weeks, cost seem a bit prohibitive, but then if you take into account the three modules it replaces, perhaps not that expensive, thanks for that.

With AFDD you are looking at something in the £1-2k region for a full CU at trade price, so it is something that is a very difficult to sell to most folk.

It is also a little unclear as to how effective they are in real terms, and so far no test equipment that I know of so for the 'AFDD' aspect you are trusting the self-test, though obviously you can verify the RCD action which provides some confidence on the electronics and mechanical trip reaction.

I suspect they will come down in price though but no idea how long for that to show.
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I have come to the conclusion that you can't get true separation of 3mm on each pole without the extra width, which seems logical when you consider the doubling up of the number of mechanical components needed, obviously flying leads are not required.

I can't see a problem in getting 3mm clearance when open, but I can see a problem in having an arc-quench chamber in a single-module size device if you were interrupting a N-E fault at high current.

Do you have a specific reason for needing this?

 

[Mike Johnson]

I think you'r right, the problem is IMO, domestic electrical instals are to a greater extent very reliable, so it's not seen as a priority to improve what is already working well, the old adage "If it ain't broke......." seems to be the majorities mantra.
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@pc1966 the only reason for needing this is the French regulations which stipulate dual pole 3mm gap, they are a bit behind in not using RCBO's in the main, but the availability of true dual pole units is getting better, I wont go into what I think they do better as it will start a very long debate. I am still looking for the "sat on the fence" smily.

 

[Mike Johnson]

As close as I can find, but looks painful.

 

[pc1966]

If you really need dual-pole tripping because you might have a L-N polarity reversal, etc, then it would need to be really a 2-P breaker (i.e. thermal/magnetic trips on both poles).

Is that a real concern? I guess you always have a high capacity dual-pole RCD incomer anyway due to them all being TT supplies?

 

[Mike Johnson]

The single module units offered in the UK do not have the thermal/magnetic trips on both poles, hence they do not comply with the French Regulations.

The incoming RCD is in reality set up to stop the consumer exceeding the tariff they are paying, there used to be a bit of head room to this, but with the installation of smart meters this head room has been drastically reduced, from what I have been told from 10% to 2%, most consumers who where on the limit prior to the change over have to upgrade their tariff at a cost.