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Compact RCBOs


Onoff

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Is this a major manufacturer finally seeing the light?

 

Single module compact RCBO. Still only one way in/out and still with a reference fly lead but interesting none the less:

 

https://www.wylexreasons.co.uk/?dm_i=8TT,5E1UN,OHEQG7,KUO5L,1

 

EDIT: Note how it says "fully complies" (with the regs). Adds weight to those of us of the opinion that anything other than all RCBO DOESN'T COMPLY!

Edited by Onoff
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If it were me I'd fit them, or get a sparky to buy the trade-only ones that have been mentioned before.

 

No reason at all for anyone to refuse to fit them.  The electrician I worked with thought that me insisting on an all-RCBO board was a good idea, and couldn't understand why the compromise had been made with the 17th Ed to introduce the split board, with just two RCB zones.

 

The big advantage of an all-RCBO board is that only the faulty circuit trips, all the others keep working as normal, which is not only more convenient, but it helps to pin down where the fault may be.

Edited by JSHarris
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2 hours ago, recoveringacademic said:

@Onoff, I have watched the video,  twice. With the the best will in the world, I'm never going to understand it. 

Which makes me ask;

  • Do I ask my sparky to fit them?
  • What reason  might he give for refusing to fit them? [ A refusal from a sparky is a big deal for people like me]

Ian

 

I wasn't saying "fit these Wylex RBCOs" just to be clearon that. I was alluding to the fact that what is a major manufacturer (Wylex) appears to be moving towards the small form / compact / same size as an MCB, RCBO.

 

Wylex are a big name in consumer units but they're just a bought out "trusted" name of yesteryear now under the umbrella of the Electrium consortium. Wylex, Volex, Crabtree, all cu makers & all owned by Electrium. They were all hit by a serious breaker recall a few years back. Note the Steeple, Sector, Alto etc brands. Punted by this that or the other electrical wholesaler as "their" own line. Bites from the same cherry! So you had all these "names" re-badging the same basic kit in what, the name of profit, perceived wider choice by the customer?

 

https://www.electricalsafetyfirst.org.uk/product-recalls/2012/02/electrium-miniature-circuit-breakers/

 

Then, MK (not Electrium owned) themselves had faults with their main switch incomer issues.

 

https://www.electricalsafetyfirst.org.uk/product-recalls/2013/04/mk-sentry-switches-and-consumer-units/

 

Even Hager, Square D etc have had recalls. (Don't forget Square D, Merlin Gerin are both Group Schneider).

 

https://www.electricalsafetyfirst.org.uk/product-recalls/2016/10/hager-minature-10ka-circuit-breakers/

 

- Plain and simple no ifs, buts or maybes  ONLY all RCBO cus comply with the regs. OK, the regs aren't law but what else do you have if you don't abide by them?

- Compact RCBOs are common in other countries

- The ones available here should hold all relevant BS, EN approvals

- Some switch both live and neutral off in the event of a fault which is desirable for multiple reasons

- Some allow you to wire them with the feed or outgoing circuit either side.

- Some don't have the flying earth and reference neutral leads. Means less wiring, neater install in the cu

 

These new Wylex ones are small, given, BUT retain the flying neutral and only allow wiring one way up. To my mind they could have gone further. However.....it's Wylex, many people's favourite. They will likely fly off the shelves. Go back 30 years and I loved Wylex.

 

Personally I would ask your sparks what he thinks of SBS. Dave there is very approachable and would happily chat to him.

 

https://www.sbstradesales.co.uk/technical-considerations/

 

They have been offering the benefits of compacts for the last 5 years. If concerned that SBS is a small player, maybe without the "clout" of Wylex then go to them but the cu will be more cluttered. As above though even the "big boys" have had recall issues. You could argue their systems will pick up recall issues quicker but then counter that with SBS being a smaller, more personal service company with a reputation to build. They're all mostly made in China anyway!

 

Yes, btw I will be having an SBS cu in my own house. Slight problem in that the wall where it's going isn't there yet.....and you know how long I take! :)

 

 

 

 

 

 

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1 hour ago, dpmiller said:

 

Garo is a Swedish company and I think the stuff is made in Poland? I think they are line / load side specific so wire 'em up wrong and they go bang. Could be wrong. Have a feeling they had at one time a short circuit capacity of 4.5KA but seem to have upped that to 6 now. I don't know if they are true DP and switch the neutral in the event of a fault.

 

I'll find out!

 

EDIT: They appear to be true DP but only wire one way:

 

garo.png.befce061c82fcc2d7dd452030acaa7ca.png

 

Some have a solid neutral

Edited by Onoff
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Schematic on a typical SBS Compact RCBO:

 

IMG_3177.thumb.JPG.704eb1c1d92e4ee1b58fcf0c29600708.JPG.07603d8614a3831a23c0bda64b003585.JPG

 

This from Dave at SBS:

 

"The GARO is a true 2-pole device, but its biggest size is 25A. Probably couldn't achieve 6KA at bigger sizes.

Couldn't therefore deal with 32A rings or 40A showers.

It is LIVE IN at the bottom only, which shouldn't be a problem in the UK."

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Pity about the 25A max, as these otherwise look to be the dog's danglies.  I have a three 32A RCBOs plus a 50A RCBO on the water heater feed.

 

Looks like a good set up for a radial wiring set up with no heavy loads though.  I still wish I'd had room to radially wire our build, but I was just to short of wall real estate where all the electrics had to go to take the bigger CU needed.

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12 minutes ago, JSHarris said:

Pity about the 25A max, as these otherwise look to be the dog's danglies.  I have a three 32A RCBOs plus a 50A RCBO on the water heater feed.

 

Looks like a good set up for a radial wiring set up with no heavy loads though.  I still wish I'd had room to radially wire our build, but I was just to short of wall real estate where all the electrics had to go to take the bigger CU needed.

 

SBS DP Compact, single module RCBOs go to 40A.

 

SBS do the bigger, standard height 50A RRCB-B50L. This has flying neutral and earth leads and is £12.

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This thread has made my brain ache.  And thus the more enjoyable. Just like being back at work all this just-in-time learning.

 

I have done a good deal of YT research (mainly John Ward's stuff )  However, I think I learned just enough (in the last 24 hours) to be able to talk to the sparky and maybe - just maybe - understand what he says.

 

I have got this  far with my thinking and wonder if any of you might nudge me a step or two further, please?

On the don't buy a dog and bark yourself principle, and in the context of our piggery (not the main house)

 

On 17/01/2018 at 20:13, Onoff said:

I wasn't saying "fit these Wylex RBCOs" just to be clear on that. I was alluding to the fact that what is a major manufacturer (Wylex) appears to be moving towards the small form / compact / same size as an MCB, RCBO.

[...]

- Plain and simple no ifs, buts or maybes  ONLY all RCBO cus comply with the regs. [...]

- Compact RCBOs are common in other countries

- The ones available here should hold all relevant BS, EN approvals

- Some switch both live and neutral off in the event of a fault [...]

[...]

Ask my electrician to fit a CU with

  • RCBOs only
  • If possible compact RCBOs
  • If possible RCBOs that cut off Line and Neutral at the same time (Double Pole  RCBOs)

In our piggery, I anticipate needing circuits for LED lighting,  10 standard sockets, and a  car  charging point, and a couple of spares. But I bet I'll have missed something, so make sure there's space in the CU

 

Which takes me to @JSHarris point

19 hours ago, JSHarris said:

Pity about the 25A max, as these otherwise look to be the dog's danglies.  I have a three 32A RCBOs plus a 50A RCBO on the water heater feed.

[...]

and  @Onoff's response

 

19 hours ago, Onoff said:

SBS DP Compact, single module RCBOs go to 40A.

[...]

 

If I need more than 40 amps, then I'll have to use the bigger form of RCBO.

 

I really like the Schneider range of CUs because they have lots of room in them and the terminals are on the left and right hand side. That makes it easier for me to work in them (under appropriate supervision) because of my Bend-It-With-Beckham hands.

 

What have I missed?

Before I forget, thanks very much @Onoff and @JSHarris 

Ian

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2 hours ago, ProDave said:

 

[...]

All I would add is the type that SBS sells, with a dual busbar is better as you don't have the flying neutral lead from each rcbo to terminate. Point your sparky to SBS so he can see for himself.

[...]

 

Thats interesting.... The second busbar obviates the need for the flying neutral, then? (excuse the possibly stupid question)

Ian

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5 minutes ago, recoveringacademic said:

 

Thats interesting.... The second busbar obviates the need for the flying neutral, then? (excuse the possibly stupid question)

Ian

 

Yes, and makes for a MUCH tidier CU, with more room to lay things out neatly.  All those flying leads always end up making the box cluttered and a PITA to work on, IMHO.

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23 hours ago, JSHarris said:

Thanks for that, so you could "mix and match" DP RCBOs for the lower loads, with a few bigger SP ones for the higher loads?  That neatly gets around the problem for things like electric water heaters that need a higher rated one.

 

Yes. The picture below from SBS shows a line of Compact RCBOs on the left then two MCBs before the main switch. Subsitute full height RCBOs for the breakers:

 

5a60c576cff15_boardwithTDRCDandMCBs.JPG.3a711b4d779adc690b8b347df7e04e15.JPG.9da5688167d067446adc33d2df593b29.JPG

 

The busbar along the bottom is in fact two, one for L and one for N insulated from each other. They pick up from the main switch. Only the Compacts are fed like this. The full height RCBO's (or mcbs in this case) are fed conventionally.

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1 hour ago, SBS Dave said:

Thanks OnOff for your support.

The photo shows the double busbar setup. Note, in the previous photo, I also fitted a 100A/100mA TD RCD in place of a Main Switch, as specified by my customer.

SBS Dave

IMG_2868.JPG

 

Hello Dave, first post! You might want to introduce yourself on here.

 

I'm sure you'll get a few questions direct now!

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As I recall, the customer was supplying 2 outbuildings via the 2 x MCBs. The outbuildings each had an RCBO board.

The TD RCD provided protection for the feed cables to the boards, whilst providing discrimination between the TD RCD and the series connected RCBOs in the boards.

 

Thanks for the welcome OnOff and I will be happy to answer any questions the Forum may have. I am not here to promote my Company or its products, as I am sure the Moderators would take a dim view of that.  If anybody wants more information, please PM me.

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16 minutes ago, SBS Dave said:

Thanks for the welcome OnOff and I will be happy to answer any questions the Forum may have. I am not here to promote my Company or its products, as I am sure the Moderators would take a dim view of that

 

Dave - you have a PM... :ph34r:

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Ah! I didn't realise the board was feeding sub mains. 

 

I thought it was an overkill seeing as you are using Compacts hence no fly leads!

 

For others here thinking wtf, consider a metal cu on a TT system.  The earthing arrangement is likely nowhere near as good as with TN systems. The incoming meter tails are stranded copper cores that are sheathed and insulated, in effect double insulated but it's actually wrong to call them that even though the sheath is insulating! They will come in through a plastic gland. Quick CAD sketch (in lieu of my earlier fag packet sketch - felt the thread deserved better):

 

cu2.JPG.84c10ca3171c2a6795ad7d0f43dabf8a.JPG

 

You have in the cu for want of a better word "fly leads" from the main switch to the individual RCDs in the case of a split load board. These fly leads are single insulated. They're also pretty flexible by construction. Add to that the modern move away from two screw terminations in main switches to one bfo screw (bad move imo). That's a big bone of contention on the basis it's easy for it to loosen. NEVER, EVER think that these screws are factory tightened properly, always check.  

 

So with potentially dodgy single screws and springy, single insulated, flexible conductors, if one comes adrift it could easily touch the metal enclosure...and that's BAD! :) Wasn't a huge issue before when a TT enclosure had to be made from "plastic". 

 

So the way round this, in a TT is to fit an upfront TD RCD in place of the normal DP main switch. Wire comes adrift, touches the case, TD RCD trips. The 100mA rating is there to give fault protection for the single insulated cables that feed the 30mA RCDs. If you put a normal, no time delay 100mA RCD in front of the line of 30mA RCDs it doesn't guarantee it won't trip first hence the time delay element. Only a TD 100mA provides proper discrimination.

 

There's a lot of confusion over time delay but think of it like this: A fault occurs on an outgoing circuit in excess of 100mA you would think that it should trip the 30mA RCD first if that's before a 100mA RCD. But normal BS EN RCDs (& RCBOs) only have to trip within 300ms. The issue is that the 100mA RCD if non time delay may react quicker than the 30mA RCD. Making the 100mA RCD time delay gives the 30mA a chance to trip first. Hope that makes sense.

 

If you look at the SBS Compact assembly the bus bars take the place of the single insulated fly leads. They're affixed at multiple points and can't really come undone and spring against the enclosure. 

Edited by Onoff
Added: "touches the case" + added CAD sketch
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