Are different brands of MCB interchangeable?
mike
32A MCB for a new ring main.
I'd assumed that different brands of MCB were interchangeable until I
saw how many different brands at similar prices Toolstation stocked -
and that made me think there must be a market for specific makes.
Toolstation don't do Wylex though -- so will other brands do?
Thanks in advance.
Bob Minchin dangling via a dongle
Bob
Andrew Gabriel
In general, they aren't. Even if they mechanically fit, you're
going to be running outside the design and test criteria.
MCB's have issues with heat and magnetic fields straying from
one to another. One manufacturer will ensure their own work
correctly when used as specified, but they aren't going to go
to the trouble of making theirs work with alien stray fields
leaking in from someone else's.
There are some which are well known to be interchangable, such
as MEM, BILL, Eaton, because they're really all the same company
and production line.
Note that individual manufacturers often have several ranges,
and they often aren't even interchangable.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
Tim W
wibbled on Thursday 29 October 2009 19:06
You would be well advised to use the correct part. Some form factors to vary
and technically, a Wylex assembly will not have been type tested with other
manufacturer's devices in.
Having said that, sometimes the same parent manufacturer makes stuff under
different names and those devices may be interchangeable.
--
Tim Watts
This space intentionally left blank...
John Rumm
> I need to swap an unused 40A Wylex MCB in a Wylex consumer it for a
> 32A MCB for a new ring main.
>
> I'd assumed that different brands of MCB were interchangeable until I
> saw how many different brands at similar prices Toolstation stocked -
> and that made me think there must be a market for specific makes.
There is *some* interchangeability, but its certainly not universal.
Even in cases where they do fit, you may find small differences in
positioning of components that may make getting the fingers on bus bars
in the right place, or the projections mounted through the apertures on
cases etc.
> Toolstation don't do Wylex though -- so will other brands do?
Although incomplete, an early stab at an interchange chart is available
here. Note the chart is incomplete - just because there is no X in a box
does not mean that it won't fit!
http://wiki.diyfaq.org.uk/index.php?title=Consumer_Units#Device_interchangeability
Note that using "foreign" parts in a CU will probably violate its type
approval (not that means its any less safe, just it has not been tested
and proved as such).
Its also a bit of a moving target - makers tend to redesign ranges from
time to time and new ranges may be incompatible with old.
--
Cheers,
John.
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Mike Clarke
> Although incomplete, an early stab at an interchange chart is available
> here. Note the chart is incomplete - just because there is no X in a box
> does not mean that it won't fit!
>
>
http://wiki.diyfaq.org.uk/index.php?title=Consumer_Units#Device_interchangeability
I have a Siemens Stratum CU for which it's now well nigh impossible to get
parts. Hager RCBO's fit this box and appear to work without any problems.
Perhaps it would be worth adding this to your list for the benefit of
anyone else unfortunate to have one of these rare CU's.
--
Mike Clarke
John Rumm
Ta, added.
Roger R
"Andrew Gabriel" <and...@cucumber.demon.co.uk> wrote in message
news:hccqkk$ik7$1...@news.eternal-september.org...
>> I'd assumed that different brands of MCB were interchangeable until I
>> saw how many different brands at similar prices Toolstation stocked -
>> and that made me think there must be a market for specific makes.
>>
>> Toolstation don't do Wylex though -- so will other brands do?
>
> In general, they aren't. Even if they mechanically fit, you're
> going to be running outside the design and test criteria.
> MCB's have issues with heat and magnetic fields straying from
> one to another. One manufacturer will ensure their own work
> correctly when used as specified, but they aren't going to go
> to the trouble of making theirs work with alien stray fields
> leaking in from someone else's.
I would have thought the Electromagnetic Compatibility (EMC) regulations
required these devices to be compatible (not interfere) with each other.
Stray fields are certainly covered by the regulations, and should not
interfere with adjacent equipment.
I am no expert on these regs and whether individual MCB's can be
considered separate pieces of equipment is debatable.
As they are an individual item sold separately its quite probable they
should comply wherever fitted.
Explanatory note:
http://www.uk-legislation.hmso.gov.uk/si/em2006/uksiem_20063418_en.pdf
Regulations:
http://www.uk-legislation.hmso.gov.uk/si/si2006/20063418.htm
Roger R
ARWadsworth
"Mike Clarke" <UCEb...@milibyte.co.uk> wrote in message
news:g6WdnSBJhdoogHfX...@brightview.co.uk...
You star Mike.
I was working on a Siemens Stratum today and I was going to spend tonight
looking for a second hand Siemens RCBO on the internet.
Incidentally the Siemens Stratum is identical to one of the old MK CUs (for
which you also struggle to get parts).
Thanks
Adam
ARWadsworth
"mike" <mike...@yahoo.com> wrote in message
news:2ea37df2-c2d0-4e8b...@j9g2000prh.googlegroups.com...
B&Q sell Wylex MCBs but you will be about �5 better off by calling into your
nearest electrical wholesalers to buy one.
Adam
mike
standardisation would actually be useful.
Mike Clarke
> I was working on a Siemens Stratum today and I was going to spend tonight
> looking for a second hand Siemens RCBO on the internet.
Glad to know the info was useful.
In my case the need to add extra RCBO's was because of a major kitchen
refit. In view of the part P implications I had the wiring done by an
appropriately registered sparkie. He was working on a new CU installation
nearby before starting our job so called round with a handful of different
breakers to try for size in a spare slot. I don't remember what the other
ones were but the Hager one fit OK. I'd assume Hager MCB's should fit too.
The main switch was also in a bad state with part of the casing broken off.
It had been like that since we moved in but was functional and (reasonably)
safe bur scary looking so we had that replaced as well. When he was
initially checking things for size he had a Hager and a Wylex one with him,
they both looked like they would be possibles when slotted onto a couple of
adjacent spare ways to check for size. When he came to do the job it was a
Wylex main switch that was in the van so that's what we now have. I'd
expect Wylex MCB's to have a similar profile to this so they would probably
also be compatible with this CU but I'm not sure about their RCBO's - I
can't remember if he tried one for size on the first visit.
> Incidentally the Siemens Stratum is identical to one of the old MK CUs
> (for which you also struggle to get parts).
Perhaps the Wiki needs updating to highlight the incompatibility between the
two different flavours of MK?
--
Mike Clarke
ARWadsworth
Perhaps I ought to try to remember to write down which MCBs I have seen in
different CUs when at work and then I could contribte to that wiki
article:-)
Adam