Why does the UK use rings for sockets?

[telectrix]

No fly leads on either

Isobar P is the first LV distribution board to have a plug-on RCBO (residual-current circuit breaker with overcurrent protection) capability. RCBO neutral and functional earth connections are usually wired into the neutral and earth terminals inside the distribution board, costing significant time by introducing additional wiring. With the new Acti9 Isobar P, installers can simply plug their RCBO directly into the board. This eliminates the need to cut, straighten or dress any excess wiring therefore reducing installation time by half.

not seen these as yet.

 

[Mike Johnson]

Contactum make dual pole RCBO's to international standard which in France, Switzerland and Germany it is a requirement to disconnect the neutral on activation: 40 Amp 30mA RCBO - 2 Module - Contactum - https://www.tlc-direct.co.uk/Products/CPBR402.html

 

[Ian1981]

not seen these as yet.

See link above
[automerge]1587651329[/automerge]

Contactum make dual pole RCBO's to international standard which in France, Switzerland and Germany it is a requirement to disconnect the neutral on activation: 40 Amp 30mA RCBO - 2 Module - Contactum - https://www.tlc-direct.co.uk/Products/CPBR402.html

2 modules is Far too big for some of the domestic CU’s and won’t fit in 3phase DB’s
Wylex and Crabtree do a single module type which is DP

 

[pc1966]

2 modules is Far too big for some of the domestic CU’s
Wylex and Crabtree do a single module type which is DP

I went with Wylex for that reason, but in my case it is more about ease of testing.

Another difference is in the UK a TT supply with a RCD incomer is relatively rare so you don't usually have to worry about a N-E fault tripping the RCBO and that, if single pole, will not isolate the N fault so the main incomer RCD might also trip.
[automerge]1587652030[/automerge]
Unfortunately the Wylex DP RCBOs are not approved for use in their 3-phase boards. Doh!

 

[Ian1981]

I went with Wylex for that reason, but in my case it is more about ease of testing.

Another difference is in the UK a TT supply with a RCD incomer is relatively rare so you don't usually have to worry about a N-E fault tripping the RCBO and that, if single pole, will not isolate the N fault so the main incomer RCD might also trip.

DP rcbos is definitely a consideration and necessary for that reason but you can have a domestic CU with just a mains switch isolator giving you your DP isolation and just single pole rcbo’s for the final circuits. Same principle for 3 phase, as long as the tails are subject to non movement and enter a ferrous material in a suitable gland etc, and are the insulated and sheathed type
[automerge]1587652277[/automerge]
[Unfortunately the Wylex DP RCBOs are not approved for use in their 3-phase boards. Doh!
[/QUOTE]
Why not?
If it’s because of them being only 6Ka then they don’t necessarily need to be greater than 6Ka, all would depend on the PFC and if there’s sufficient back up protection/ coordination if the breaker can’t break the fault current.

 

[pc1966]

Why not?
If it’s because of them being only 6Ka then they don’t necessarily need to be greater than 6Ka

Not the current, though 6kA is low for a TPN board. It might be the phase barriers are not up to 400V or something, but whatever the reason they are not listed by Wylex as approved.

 

[Ian1981]

Not the current, though 6kA is low for a TPN board. It might be the phase barriers are not up to 400V or something, but whatever the reason they are not listed by Wylex as approved.

Something to bare in mind, cheers.

 

[pc1966]

I could ask Wylex technical support about it, but I doubt I will get an answer until 2023 or so...

 

[Mike Johnson]

They are also made by Hager, Siemens and Schneider without flying leads, I have Hager three phase and neutral in my DB in France.
[automerge]1587654408[/automerge]
Hager two pole RCBO without flying leads: ESR RCBO B Curve 6KA 2 Pole Domestic Consumer Unit Circuit Breaker Electrical World - https://www.electricalworld.com/en/ESR-RCBO-B-Curve-6KA-2-Pole-Domestic-Consumer-Unit-Circuit-Breaker/m-2241.aspx
[automerge]1587654539[/automerge]
Sorry wrong link they are ESR not Hager.

 

[R-fur]

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

 

[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.
[automerge]1587809409[/automerge]
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.