RCD or RCBO consumer unit

[Fazz711]

Hi .

I normally do industrial electric work.
Usually on Schneider and Merlin Gerin boards

I am looking at fitting a new consumer unit at home and seem to be getting two versions of which board would suit best.

Either a dule RCD board with MCBs
Or A board with all RCBOs.

Which would be best and why?

 

[newfutile]

Rcbo board anytime,keeps faults separate and you don't need to worry about the 9ma leakage current limit on any 1 rcd. I only fit full rcbo boards with spd for single phase

 

[Fazz711]

Rcbo board anytime,keeps faults separate and you don't need to worry about the 9ma leakage current limit on any 1 rcd. I only fit full rcbo boards with spd for single phase

Thanks.
Any recommendations on type.

I usually fit Schneider stuff and I can find one with the right RCBOs I need but will consider other if any are recommend as better.

 

[Tom256]

Thanks.
Any recommendations on type.

I usually fit Schneider stuff and I can find one with the right RCBOs I need but will consider other if any are recommend as better.

What do you mean by 'better'

 

[littlespark]

Hager or Fusebox….. or whatever I get the best price on.


As explained above, all RCBO gives better separation of circuits the dual RCD, losing only one circuit instead of a bunch of them.
Possible nuisance trips are harder to diagnose.

Only downside is the increased initial cost.


What’s the physical location like for space to fit in a new board?
All mine seem to include destroying some well built cupboard surround,

 

[Fazz711]

Hager or Fusebox….. or whatever I get the best price on.


As explained above, all RCBO gives better separation of circuits the dual RCD, losing only one circuit instead of a bunch of them.
Possible nuisance trips are harder to diagnose.

Only downside is the increased initial cost.


What’s the physical location like for space to fit in a new board?
All mine seem to include destroying some well built cupboard surround,

It lives above kitchen cupboard.
I was going to box it in when I fitted the kitchen but it didn't happen.
Glad now as plenty of room.

 

[brianmoooore]

RCBOs can help with the space problem. Going from dual RCD to RCBOs releases four modules on the DIN rail, which may allow you to go down a size in enclosure.

 

[littlespark]

It lives above kitchen cupboard.
I was going to box it in when I fitted the kitchen but it didn't happen.
Glad now as plenty of room.

That doesnt sound like its easily accessible for swapping out.

Be prepared to take the cupboard down to give you some more working space.

 

[Fazz711]

This is the space

 

[Fazz711]

RCBOs can help with the space problem. Going from dual RCD to RCBOs releases four modules on the DIN rail, which may allow you to go down a size in enclosure.

I have eight RCDs and only use seven.

The Schneider one I think is 12 and comes with eight RCBOs and will cover what I need

 

[Fazz711]

What do you mean by 'better'

Maybe easier to fit or cheaper more available parts
Better quality.

 

[brianmoooore]

You don't appear to be limited in space horizontally, as is often the case, so my comment isn't really applicable here.
Is that meter as your supplier left it?

 

[Fazz711]

You don't appear to be limited in space horizontally, as is often the case, so my comment isn't really applicable here.
Is that meter as your supplier left it?

No I had the twist it when I fitted the kitchen

 

[mainline]

A fusebox dp rcbo board is my goto one.

I always now use DP rcbos as in the case of an N To E fault sp ones won't clear the fault.

Especially recommended on TT that uses an upfront Rcd.

 

[Fazz711]

A fusebox dp rcbo board is my goto one.

I always now use DP rcbos as in the case of an N To E fault sp ones won't clear the fault.

Especially recommended on TT that uses an upfront Rcd.

I like Schneider ones as that is what I have most experience of from years of industrial work.

Having looked at fusebox ones I am leaning that way.

 

[EricMark]

Step one, measure the leakage, I have 8 mA spread between 14 RCBO's after losing two freezers full of food, not taking that chance again, my freezers are supplied from the UPS with RCD sockets, so likely tripping is unlikely.

But guessing is not the way to go, you look at background leakage, then decide.

 

[mainline]

View attachment 121156 Step one, measure the leakage, I have 8 mA spread between 14 RCBO's after losing two freezers full of food, not taking that chance again.

There's always a chance of a rcbo tripping, even when there's nothing wrong with the installation or appliance.

 

[Teddy Lop]

Sorry I don't mean to be that person on the Internet, maybe there's something unsaid or I'm being cynical, but I'm puzzled how someone who installs distribution equipment would not be familiar with RCBO v Dual RCD pros&cons?

Dual RCD's are wretched things and I always felt a bit dirty when fitting one, I'm told the "they" never envisioned such a thing and were anticipating greater use of RCBO's but due to their failure to anticipate the market looking for loopholes to find cheaper solutions (especially with overblown complex wording of rules where simplicity would suffice), the dualies quickly materialized and the they permitted their use in preference to admitting they could have done their job better.

With the low cost of RCBO's today they're a no-brainer, but even before on small installs they didn't add much more, and as you go larger the benefits of RCBO's only become more prevalent. The dual sweet spot (if such a thing can be said to exist) was probably 3-5 circuits per RCD, as you sail past that you're stretching the obligations for things such as minimisation of nuisances IMHO.

I explain the benefits of RCBO to every prospective client and 95%+ are happy to pay the extra, most dualies i fit are builder or landlord insistence, and most of the clients I talk to about their dualies, particularly when doing a bit of fault finding, are chagrined at never having had an explanation or the option!