Another which RCBO/MCB compatibility question!

[MrPupsi]

Need a 6a RCBO for a lighting circuit otherwise it’s a 18 circuit board change!

Had a quick search on here, and Alto is Wylex rebranded?
If so, will the NHX mini RCBO series be a suitable replacement?

 

[IAmSparkytus!]

This won't help answer your question but had to install a circuit in a shop today where the breakers for the fuse board were obsolete according to the wholesalers but the board had Merlin and Chint breakers installed which fit really well.

Can't see the harm in fitting a different brand of breaker if it fits just as well as the correct ones did but decided against it and fitted a new 4 way DB instead.

I know you aren't supposed to fit different brands in a board but what's the general consensus? Do you all do this or not?

 

[Dustydazzler]

I would rather source a second hand breaker in the correct make

but worse case some breakers / rcbos can be mix n matched like old wylex with alto we’re exactly the same just rebranded

 

[Dartlec]

It can be a struggle even matching new Wylex with slightly older Wylex, depending on the busbar type ... There was a post recently clarifying which it was I believe, but there are two models now and only one will fit with some of their older stuff....

Picture showing the busbar might help - someone has probably faced the same issue...

Or pick up a Wylex MCB and see if that fits well, if so then you'll know the RCBO should be OK.

 

[MrPupsi]

Cheers gents.

Regarding the comment in post #2, I don’t see it as much of an issue if the MCB/RCBO fits correctly and the front cover sits on properly.
In the BPG it does mention this and classes it as a C3, provided the above is met.

It’s something I’d rather avoid, but sometimes practicality and cost has to intervene. To swap over a 17 way board for the sake of RCD protecting 1 circuit is just bonkers to me.

Whilst a manufacturer won’t recommend it, all these devices are made to same BS, so I do feel comfortable and confident in fitting mix/match if need be.

Will give a few MCBs a go tomorrow and post up my findings!

 

[Dartlec]

Do report back - always good to have reports of ones that do fit - I'm always meaning to put together a proper list, but lack the motivation/time...

 

[MrPupsi]

Went to the wholesaler and matched up a bunch of different breakers, and Proteus mini RCBO was a good fit.
Sits straight on the din rail and busbar, only protrudes a bit further than the Alto but lid closes comfortably.

Happy days!

 

[grumpyjohn01]

It can be a struggle even matching new Wylex with slightly older Wylex, depending on the busbar type ... There was a post recently clarifying which it was I believe, but there are two models now and only one will fit with some of their older stuff....

Picture showing the busbar might help - someone has probably faced the same issue...

Or pick up a Wylex MCB and see if that fits well, if so then you'll know the RCBO should be OK.

Further to my last post on this, I was perusing the current online Wylex catalogue yesterday for something else and came across a section concerning retrofits (pg 41 IIRC of consumer unit catalogue). It depicts the different busbar types historically supplied and gives a compatibility table. Its not entirely clear...! but additional info nonetheless. I identified other typo's on part numbers etc in other sections so might not be accurate either! Say what you like about Wylex but they certainly produce a comprehensive range of kit.

 

[Zerax]

I don’t see it as much of an issue if the MCB/RCBO fits correctly and the front cover sits on properly.

And of course the busbar lines up correctly underneath... (which is probably more important)

 

[Dartlec]

Further to my last post on this, I was perusing the current online Wylex catalogue yesterday for something else and came across a section concerning retrofits (pg 41 IIRC of consumer unit catalogue). It depicts the different busbar types historically supplied and gives a compatibility table. Its not entirely clear...! but additional info nonetheless. I identified other typo's on part numbers etc in other sections so might not be accurate either! Say what you like about Wylex but they certainly produce a comprehensive range of kit.

That's the picture/table I was looking for.

But I think one issue is that a lot of older Wylex I've seen use a different busbar to the two 'pre 2018' options they give. Whether it was an official Wylex busbar or just what anyone had to hand is another matter...

I note they seem to say that their AFDDs won't fit any pre-2018 units though - how convenient....

 

[HappyHippyDad]

Do report back - always good to have reports of ones that do fit - I'm always meaning to put together a proper list, but lack the motivation/time...

Yeah yeah, you've been saying that for ages ?

Am just about to update my MK RCBO thread with some pics, you could pop it in your records.

 

[grumpyjohn01]

That's the picture/table I was looking for.

But I think one issue is that a lot of older Wylex I've seen use a different busbar to the two 'pre 2018' options they give. Whether it was an official Wylex busbar or just what anyone had to hand is another matter...

I note they seem to say that their AFDDs won't fit any pre-2018 units though - how convenient....

They were definitely supplying flex busbar types pre 2018 that look more like the top one in the post 2018 part of the table. I am fairly sure these were often found in 'custom' units supplied in bulk to large contractors engaged in social housing work for specific layouts common to eg an estate of similar houses. I was doing this sort of work back in mid 00s and remember them being supplied in a populated state with 'special' part numbers, red clip breakers iirc.

 

[GBDamo]

Shouldn't be mixing and matching CU components any more.

Saying its only a C3 I get but it's a non-compliance and we should not be installing non-compliances.

It's difficult as if you don't do it there's always someone who will leaving you looking like you're trying to rip the customer off.

Another one of those regs that seem to have been written for the benefit of the manufacturers rather than the safety of the customers.

 

[Dartlec]

They were definitely supplying flex busbar types pre 2018 that look more like the top one in the post 2018 part of the table. I am fairly sure these were often found in 'custom' units supplied in bulk to large contractors engaged in social housing work for specific layouts common to eg an estate of similar houses. I was doing this sort of work back in mid 00s and remember them being supplied in a populated state with 'special' part numbers, red clip breakers iirc.

That makes some sense - The one I came across was in an ex council house, though it had a standard solid MK type busbar - which isn't on their list at all....

I have some on a Din rail here, and the NHX will only fit the even older NSB models using the balcony connection type busbar, not the bottom terminal....

 

[grumpyjohn01]

Shouldn't be mixing and matching CU components any more.

Saying its only a C3 I get but it's a non-compliance and we should not be installing non-compliances.

It's difficult as if you don't do it there's always someone who will leaving you looking like you're trying to rip the customer off.

Another one of those regs that seem to have been written for the benefit of the manufacturers rather than the safety of the customers.

Yep bad faith regs like bad faith laws are there to be summarily ignored if you believe you have grounds..its the only real way to show disapproval.
Having said that, I do try to avoid mixing & matching if at all possible but in the right circumstances, have no problem.

 

[grumpyjohn01]

That makes some sense - The one I came across was in an ex council house, though it had a standard solid MK type busbar - which isn't on their list at all....

I have some on a Din rail here, and the NHX will only fit the even older NSB models using the balcony connection type busbar, not the bottom terminal....

I've still to revisit the job I have try a new NHX RCBO in, its still rattling around in the van..
Would be interested to see a pic of the 'standard solid MK type' you mention as it doesn't ring any bells.

 

[Dartlec]

I've still to revisit the job I have try a new NHX RCBO in, its still rattling around in the van..
Would be interested to see a pic of the 'standard solid MK type' you mention as it doesn't ring any bells.

Not sure what the official name is - Similar to the one Wylex call 'fixed - cage connection' in their image, but not fixed.

This sort:

 

[grumpyjohn01]

Not sure what the official name is - Similar to the one Wylex call 'fixed - cage connection' in their image, but not fixed.

This sort:

mm don't think I ever came across that type tbh

Not sure what the official name is - Similar to the one Wylex call 'fixed - cage connection' in their image, but not fixed.

This sort:

Don't think I've seen that one, but really should fit all the cage clamp type devices unless of course its a hack job and doesn't have the proper set for the main switch in which case none of it will fit properly