Why do we do it the way we do in the UK?

[Electrics]

Was just watching a video of an RCBO install and found it weird that the breakers are double pole yet still have to have a fly lead.

Why don't we do it like this:

Ignore the gibberish coming out of his mouth and take a look at the unit. L+N coming from the supply, feeding the bottom of the first RCD. All the RCD's are linked together by the linking bars running down the left, giving them all L+N feed. The feed then goes through the RCD out the top, into the bus bar that's linked across the tops of all the MCB's. The L+N of each circuit comes out the bottom. This does away with the need for a neutral bar (there is one but they are used when there is no linking bar employed and you have to run an N to each RCD), several main neutral cables and the need to fill the unit with loads of extra cabling, not to mention cost saving on the materials.

Why, even with dual pole RCBO's, do we still make them use fly leads when we could simply link them all to N via the main RCD in? Makes no sense to me.

Having said that we're still the only country i know of that uses rings.

Anyone think we'll eventually catch up and stop doing things in such weird ways? Although i guess one drawback of the way they do it in Europe is that their multi tier units are standard for almost any regular sized home and they are anywhere from £3-700.

 

[Mikegh]

Thanks I forgot the DP main isolation about time there , more harmonization with the UK

Surge protection

Dual RCDs is it , so that would be base spec in comparison to an rcbo board. ?

Didnt take a proper look yet but if they're gone from lighting mcbs to lighting on shared RCDs that would be a backward step

 

[Mikegh]

I install this tomorrow. First rewire under new regs. To my great surprise the single module rcbo and the "dreaded flylead" has invaded our shores. Our beloved 2 pole rcbo and L +N busbar is being sacrificed for space in preparation for rcbo populated DB, s.

Oops sorry I see the single mod 6amp lighting rcbos there ,proper order

 

[Mikegh]

And that's a shower rcbo too

I do shoot from the hip

Nice board

Good to see the DP main isolation and lighting rcbo kept separate from power , if its even advisable for domestic lighting in the first place which I have my doubts

 

[nicebutdim]

I install this tomorrow. First rewire under new regs. To my great surprise the single module rcbo and the "dreaded flylead" has invaded our shores. Our beloved 2 pole rcbo and L +N busbar is being sacrificed for space in preparation for rcbo populated DB, s.

Hate to break this to you, but those shores were breached some time back - now we're just slipping them over the border ?

On a more serious note, if single module RCBOs are going to become more commom in IE, it might be an idea to look at options that don't require a flylead - at least until such times as Hagar catch up.

 

[pc1966]

Thanks I forgot the DP main isolation about time there , more harmonization with the UK

What is very different though is the use of a 63A B-curve MCB as input isolator.

Certainly I think isolation should always be all-pole (though for TPN that is not so common and ideally then you want a mate first / break last on N) and I was surprised that ROI did not do so in the past.

The use of the MCB to me is kind of mixed, I can see it is a good idea to limit each CU's total current without pushing the DNO fuse in to that job (I presume ROI still has the equivalent of a fuse as ultimate limiter?) but it also seems a bad idea on selectivity as many high current faults will take out both the faulty circuit and the whole damned supply!

63A B-curve instant trip is 189-315A, though looking at the Hager tables it would be selective with a 20A B-curve for socket radial to around 700A. That is still less than often seen for PSSC on sockets here (my experience mostly the RFC, maybe easier at ends of 20A radial though?).

 

[LastManOnline]

What is very different though is the use of a 63A B-curve MCB as input isolator.

Certainly I think isolation should always be all-pole (though for TPN that is not so common and ideally then you want a mate first / break last on N) and I was surprised that ROI did not do so in the past.

The use of the MCB to me is kind of mixed, I can see it is a good idea to limit each CU's total current without pushing the DNO fuse in to that job (I presume ROI still has the equivalent of a fuse as ultimate limiter?) but it also seems a bad idea on selectivity as many high current faults will take out both the faulty circuit and the whole damned supply!

63A B-curve instant trip is 189-315A, though looking at the Hager tables it would be selective with a 20A B-curve for socket radial to around 700A. That is still less than often seen for PSSC on sockets here (my experience mostly the RFC, maybe easier at ends of 20A radial though?).

Yes. There has always been a switch fuse between the DNO and the customers DB. A short circuit on the cooker or shower circuit could potentially take the 63 amp mcb out but to date I have not experienced it. All installations are entitled to install a 63 amp "C" curve if the Fli allows for it which most will.
The DB on the picture is not available off the shelf yet in most wholesalers and I was, nt given a choice. I had to order direct from Hagar as I have a job to finish. Still struggling to get the new LZSH in all the necessary sizes due to the delays caused by covid

 

[Simon47]

Insides of an SBS board. The neutral bar tabs are visible, the live bar tabs are under a plastic cover. A bit sparse, but I wanted plenty of room for future expansion.

 

[pc1966]

Insides of an SBS board. The neutral bar tabs are visible, the live bar tabs are under a plastic cover. A bit sparse, but I wanted plenty of room for future expansion.

That looks really neat!

Are the SBS RBCOs dual-pole switching?

 

[Timbo]

That looks really neat!

Are the SBS RBCOs dual-pole switching?

Yes. Used a few now. Had an email recently saying they now do a DP MCB to fit the dual busbar system.
Also their SPD's are very reasonable price.

 

[Timbo]

Deleted duplicate post.

 

[Timbo]

Deleted duplicate post.

 

[Timbo]

Trying to attach pics, but keeps duplicating original post.

 

[freddo]

That wire has SHOWOR written on it.

 

[Mikegh]

What is very different though is the use of a 63A B-curve MCB as input isolator.

Certainly I think isolation should always be all-pole (though for TPN that is not so common and ideally then you want a mate first / break last on N) and I was surprised that ROI did not do so in the past.

The use of the MCB to me is kind of mixed, I can see it is a good idea to limit each CU's total current without pushing the DNO fuse in to that job (I presume ROI still has the equivalent of a fuse as ultimate limiter?) but it also seems a bad idea on selectivity as many high current faults will take out both the faulty circuit and the whole damned supply!

63A B-curve instant trip is 189-315A, though looking at the Hager tables it would be selective with a 20A B-curve for socket radial to around 700A. That is still less than often seen for PSSC on sockets here (my experience mostly the RFC, maybe easier at ends of 20A radial though?).

What we have is an MCB at the supply cabinet

Double pole main isolation at the main board
then

Its mostly similar to UK on the boards , heading toward all RCBOs

 

[LastManOnline]

That wire has SHOWOR written on it.

My spelling is gone to pot?