Do RCBOs need to be from the same manufacturer as the CU?

[SpaceCowboy72]

Good evening everyone.

If additional modules are being fitted in to an existing Consumer Unit, do they need to be made by the same Manufacturer as the Consumer Unit itself?

For example, could Wylex RCBOs be fitted in to a Hagar Consumer Unit?

Cheers

 

[JohnD]

1. Yes, and the same range by that manufacturer.

2. No

 

[SpaceCowboy72]

Thanks JohnD

By looking at the Consumer Unit should it be obvious what range to be looking for?

 

[JohnD]

photograph one or more of the existing devices, close up and showing its part no/identification.

 

[ericmark]

A consumer unit is a type tested distribution unit, to get the type testing it has to stipulate what units can be fitted, you may be able to get another manufacturers MCB's to fit, but then it would no longer be a consumer unit and can only be used where the control is not by an ordinary person. So technically I could fit another make in my house as I am not classed as an ordinary person. But if I want to sell or rent then I have a problem.

I have not seen a single MCB which does not have something on it that tells you the manufacturer.

 

[SpaceCowboy72]

Thanks both.
I'll try and get a picture tomorrow.

 

[SpaceCowboy72]

........ and can only be used where the control is not by an ordinary person.

Ha ha, none of the people that would be using the building are what I would call 'Ordinary', but probably not in the same context that you are referring to.

 

[winston1]

Often different makes of modules are perfect fits. I believe manufacturers come out with all this type testing stuff to make you buy their components. I've often seen mixed brands in CUs.

 

[JohnW2]

Often different makes of modules are perfect fits.

Indeed they do.

I've often seen mixed brands in CUs.

I'm sure we all have. But ...

I believe manufacturers come out with all this type testing stuff to make you buy their components.

As I understand it, it was really BS7671 who "came out with all this type testing stuff". One is free to use non-type-tested DBs (provided the components are 'suitable') but one cannot then invoke the 'dispensation' inherent in the BS7671 definition of a 'Consumer Unit' (which avoids the need for it to contain 16 kA devices).

I'm not even sure that the commercial ploy you mention would necessarily work all that well. What a manufacturer lost by people putting devices of some other make into their DBs would be at least partially compensated by the sale of their devices to be put into other maker's DBs. One might argue that people would put 'cheap' devices into a 'reputable CU', and that is bound to happen to some extent, but if a person was thinking that way, why would they not buy an entirely cheap CU/DB plus devices?

Kind Regards, John

 

[ban-all-sheds]

Often different makes of modules are perfect fits. I believe manufacturers come out with all this type testing stuff to make you buy their components. I've often seen mixed brands in CUs.

I've often seen cars wrecked because the driver has made a poor decision, so what's your point?

But type testing is a standards requirement, not a manufacturer marketing ploy so your belief is of no relevance.

 

[ericmark]

In my old house I have a fuse box, it is not a consumer unit, it was made before the type testing came out, it now has MCB's fitted there are two fuse boxes both fed from RCD's which are in a box with built in DIN rail and until the metal CU came in it complied with all regulations other than being type tested, at the point where the RCD's were added there were not any CU's with twin RCD's.

Only reason why Wilex MCB's were fitted was they were only ones that would easy fit a Wilex board, however with DIN rail mounted MCB's with a copper bus bar feeding them I have seen where massive strain has been exerted as the terminals were tightened as one make lifted the terminal to clamp and another screwed down. Strain on a RCD I have found caused it to fail to meet the tripping requirements, with an MCB they are not tested after fitting so it could result in the devices being out of spec.

"Could" is the problem, we simply don't know, no manufacturer tests a board with other manufacturers components, even 2 mm difference in bus bar alinement's could produce a strain which we are unaware of. If using loops of flex between each MCB then there would not be the strain but getting flex able to carry 100 amp is also a problem.

There will be situations where one can get around the problems, but then the CU is no longer a CU it is just a distribution unit, as to how that would effect with Part P is for courts to decide.

 

[ban-all-sheds]

Part P requires making reasonable provision in the design and installation of electrical installations in order to protect persons operating, maintaining or altering the installations from fire or injury.

I can't think of any prima facie reason why using a distribution board would make that a problem.

 

[SpaceCowboy72]

I have been told that Hager SP Type B are what I need. The CU is Hager, so I'll go down that route and wont upset the Type Testing or Regs.

 

[Risteard]

I can't think of any prima facie reason why using a distribution board would make that a problem.

All consumer units are distribution boards. See Part 2 (Definitions).

Type testing is particularly important because of Annex Zb and is also a requirement for domestic installations. DBOs are distribution boards for use by ordinary persons. You are technically free to take on the type testing yourself, but that's not a realistic option.

 

[JohnD]

I have been told that Hager SP Type B

Why does the person who told you that think that Hager has only ever made one model?

photograph one or more of the existing devices, close up and showing its part no/identification.