Anyone know of any manufactures of small recessed DB's or any other options?

[JohnS888]

Hi all

Have a job to replace 6 way recessed DB. Have looked extensively online but smallest can find is 10 way. Seems there's
limited choice with these. Don't mind if have to chisel away abit to but need something preferably near the existing dimensions which are: Width 305, Height 180, Depth 80. Any help appreciated

 

[nicebutdim]

The smallest flush CU I can think of is Proteus, but probably too tall for your recess.

Wylex made flush fit covers for some of their CUs. Is that worth exploring?


Edit: Proteus CU is taller and slightly deeper than your recess and here's an example of the Wylex covers I'd commented on, but it's also a bit too tall.

 

[pc1966]

I think you will struggle to get the height as low as that. Is it an old fuse board that is being replaced?

 

[JohnS888]

The smallest flush CU I can think of is Proteus, but probably too tall for your recess.

Wylex made flush fit covers for some of their CUs. Is that worth exploring?


Edit: Proteus CU is taller and slightly deeper than your recess and here's an example of the Wylex covers I'd commented on, but it's also a bit too tall.

Thanks mate checked out both proteus to tell like you said and the wylex lids would of been a nice work around but again unfortunately the boards the are made for them are to tall.
[automerge]1600014305[/automerge]

I think you will struggle to get the height as low as that. Is it an old fuse board that is being replaced?

It is mate it's an old MK board attached photo

 

[UNG]

Have you looked at skeleton consumer units, I have had a very quick look but difficult to work out what would fit your needs as the depth looks to be the problem
One thought might be to just use the guts and the cover of a skeleton board mounted in the existing box

 

[westward10]

Does it have to be recessed, get a big enough surface board to cover the existing hole.

 

[JohnS888]

Does it have to be recessed, get a big enough surface board to cover the existing hole.

It's at low level in tight walkway Westward. Have suggested an oversized one might be an answer to client but can understand why wouldn't be keen on this

 

[freddo]

What is the wall made of, it looks like a stud wall?

 

[JohnS888]

What is the wall made of, it looks like a stud wall?

No it's brick mate

 

[freddo]

No it's brick mate

Job done!

 

[westward10]

I wouldn't have thought a ten way would need much of a difference in hole aperture it might even be too small. The existing board is ten module with the main rcd switch with a huge gap to the left a ten way would be twelve including the main switch.

 

[freddo]

The Hager flush 10 way board is only a little wider but is about 10CM taller.

Edit I'm wrong, the box width is narrower at 298MM
The box height is 252MM, still 7CM to cut out.
Measurements in install manual here.

 

[JohnS888]

View attachment 60784
Job done!

? it's looking like it might come to that Freddo. Got a metabo wall chaser could just get my straight edges with it and just blast out the back and sides
[automerge]1600020423[/automerge]

The Hager flush 10 way board is only a little wider but is about 10CM taller.

It's 20mm to deep as well unfortunately

 

[kropaske]

BG Nexus is another one at 366x252x68 for 12 ways so you would have to cut out extra 30mm around.

https://www.bgelectrical.uk/public/downloads/data-sheets/consumer-units/CFFRSW8xx-rcd-incomer.pdf

Alternatively use existing guts as sugested above and get some fabricators to make you nice shiny cover for it

 

[SJD]

I've recently changed several recessed boards, where it was preferable to keep them recessed. Invariably the newer boards are taller, so I just accept having to chop a bit of wall out.

Obviously easier if stud, but if brick or block then either manual chisels & hammer and/or battery angle grinder (since there typically won't be mains power).

 

[telectrix]

rip out the guts. fit MK main switch and6 x RCBOs into existng recessed board. refit original front cover, appropriately labelled.

 

[JohnS888]

BG Nexus is another one at 366x252x68 for 12 ways so you would have to cut out extra 30mm around.

https://www.bgelectrical.uk/public/downloads/data-sheets/consumer-units/CFFRSW8xx-rcd-incomer.pdf

Alternatively use existing guts as sugested above and get some fabricators to make you nice shiny cover for it

Thanks Kropaske

The second option would be preferable if doable. What are you suggesting leave everything in internally including din rail? And mount RCD's, MCB's etc to this. Not sure if existing din rail likely to be suitable for this or if would be falling foul of manufacturers spec. But seems like it might be doable
[automerge]1600027937[/automerge]

rip out the guts. fit MK main switch and6 x RCBOs into existng recessed board. refit original front cover, appropriately labelled.

That's the way I'm heading Tel seems like most practical solution. Might be bit of a dumb question but is new MK main switch and RCBO's likely to fit existing din rail?

 

[UNG]

Might be bit of a dumb question but is new MK main switch and RCBO's likely to fit existing din rail?

DIN rail is a standard size because it is manufactured to the DIN standard. The MCB's, RCBO's, main switches etc are all designed to fit DIN rail

 

[JohnS888]

DIN rail is a standard size because it is manufactured to the DIN standard

Cheers mate ? I knew it was a pretty stupid question thanks for clarifying
[automerge]1600031075[/automerge]

with a bit of enginrerring ingenuity, anything can be fitted to anything. look at 1940's . american Mustang fighter was crap till we fitted a RR merlin to make it one of the best fighters of the time. and that was before the world went crazy (metric, i mean).

Very true Tel lol. Got my vote this the way forward will order bits tomorrow

 

[kropaske]

I'd still enlarge opening to accommodate new box it's going to take you half an hour or so to do it.

If you going to refit old cover check first if your new mcb's/Rcbo's are not going to stick out little bit more preventing cover to shut properly.

 

[UNG]

rip out the guts. fit MK main switch and6 x RCBOs into existng recessed board. refit original front cover, appropriately labelled.

Does the original cover meet the requirements of amendment 3 that may become the issue if trying to comply with the latest regs

 

[pc1966]

It is never a problem of fitting the DIN rail, it is the busbar matching the new switch/RCBO that is an issue.

Might be as cheap/easy to by a MK board for the main switch and matching busbar and get RCBO separately!

 

[JohnS888]

I'd still enlarge opening to accommodate new box it's going to take you half an hour or so to do it.

If you going to refit old cover check first if your new mcb's/Rcbo's are not going to stick out little bit more preventing cover to shut properly.

Thanks for heads up Kropaske had already thought of this. Just going to order a second hand old mcb and compare it to new bits for sizing to be sure it's a goer

 

[westward10]

The new devices are approximately 8mm taller through the board cover. Dimensionally when on the DIN rail they seem okay. Whether they are compatible with that enclosure in compliance with Regulations is another thing.

 

[JohnS888]

The new devices are approximately 8mm taller through the board cover. Dimensionally when on the DIN rail they seem okay. Whether they are compatible with that enclosure in compliance with Regulations is another thing.View attachment 60813View attachment 60814View attachment 60815

Top man Westward. I'll have to check whether have the 8mm to spare. It's more likely that will go with RCBO's so hopefully these won't be much bigger. Don't suppose you have one of those as well do you? ?

 

[westward10]

No but the dimensions should be the same except the rcbo will be longer which could be an issue.

 

[freddo]

I'd still enlarge opening to accommodate new box it's going to take you half an hour or so to do it.

I'd also go with this for the amendment 3 thing, assuming the existing cover is plastic. I'm not sure if mixing different devices and enclosures is allowed.

 

[JohnS888]

I'd also go with this for the amendment 3 thing, assuming the existing cover is plastic. I'm not sure if mixing different devices and enclosures is allowed.

It is metallic freddo. I hear you with covering arse with mixing enclosure but just seems to be a non issue in my opinion if din tails are all made to a certain spec and fit both same spec main switch and rcbos surely we have pretty much not changed any other important characteristics of a pre manufactured board

 

[freddo]

You are probably fine then as long as the lid closes!

 

[JohnS888]

You are probably fine then as long as the lid closes!

? it's a big if yet mate lol

 

[JohnS888]

Another query for you's. I haven't had a chance to check out supply type for property yet so there is a possibility it could be a TT earthing arrangement although very much doubt it. I find the fact that they installed a 300ma main switch pretty strange. Has 300ma circuit protection ever been a requirement in previous regs? And also as my DB is only supplying a residential property with no distribution circuits or essential services am i correct in thinking even if is a TT installation 30ma rcbos or 30ma main switch would be appropriate? I can't see why it wouldn't be. Thanks

 

[pc1966]

Having an RCD up-front above 30mA is usually a TT thing, or sometimes a fire safety for agriculture sites. 100mA is more common for domestic, but 300mA is just as acceptable provided the earth rod is below 167 ohms.

I don't think there ever has been a requirement on 30mA / 100mA / 300mA (or possibly more) as such. The main point has always been to meet ADS times and for TT that is often only possible via an RCD as you will struggle to get a rod arrangement low enough to trip even a 6A B MCB in the required times.

I suspect 100mA is the 'sweet spot' as less likely to nuisance trip than 30mA for a whole installation, and can had delay so it is selective with downstream 30mA 'additional protection' RCDs, whereas 300mA starts to demand an earth rod impedance that can be a challenge to meet all-year in some soil conditions without quite an effort for several deep rods, etc. Or the no-no of relying on a nice long buried metal water pipe...

 

[JohnS888]

Having an RCD up-front above 30mA is usually a TT thing, or sometimes a fire safety for agriculture sites. 100mA is more common for domestic, but 300mA is just as acceptable provided the earth rod is below 167 ohms.

I don't think there ever has been a requirement on 30mA / 100mA / 300mA (or possibly more) as such. The main point has always been to meet ADS times and for TT that is often only possible via an RCD as you will struggle to get a rod arrangement low enough to trip even a 6A B MCB in the required times.

I suspect 100mA is the 'sweet spot' as less likely to nuisance trip than 30mA for a whole installation, and can had delay so it is selective with downstream 30mA 'additional protection' RCDs, whereas 300mA starts to demand an earth rod impedance that can be a challenge to meet all-year in some soil conditions without quite an effort for several deep rods, etc. Or the no-no of relying on a nice long buried metal water pipe...

Thanks for clarification PC so am right in thinking then if is a TT installation if either install dual rcd board with non rcd main switch or all rcbos I have still achieved the required disconnection times. Thank

 

[pc1966]

Thanks for clarification PC so am right in thinking then if is a TT installation if either install dual rcd board with non rcd main switch or all rcbos I have still achieved the required disconnection times. Thank

If all of your final circuits are off an RCD/MCB or RCBO then you would be able to meet the ADS times on any reasonable TT earth rod setup.

Personally I would still prefer an up-front delay RCD so you don't have a single point of failure for protection in something as complex as an RCD (which is normally seen as "additional protection" along with OCPD based primary ADS protection, and in practice don't get tested by the users), but it is not a requirement as such.

 

[JohnS888]

If all of your final circuits are off an RCD/MCB or RCBO then you would be able to meet the ADS times on any reasonable TT earth rod setup.

Personally I would still prefer an up-front delay RCD so you don't have a single point of failure for protection in something as complex as an RCD (which is normally seen as "additional protection" along with OCPD based primary ADS protection, and in practice don't get tested by the users), but it is not a requirement as such.

Thanks PC very valid points. I think I'm with you on that thinking to