Mix and match of MCB's

[nickblake]

I know alot of you guys will do this but realy it should not be done .especially as the recent Electrium recall showed heres an example a recent CDU fire caused by a faulty breaker and installed by a spark the board had a mix of sector and deopoke mcb's in it when it was inspected the suppliers refused to take responcability for it due to the mix and match of MCB's ,and advised that any testing carried out would be voide , the suppliers are refusing to replace the damaged board due to this , and trading standards are now involved , consumer unit are tested to BS60439-3 with the MCB's from the same manufacturer , with the Regulations stating that the manufacturers instructions should be taken into account , if you use a mixture of MCB's from other manufacturers then it will invalidate any testing certification and warrenties and also you are then personally liable if anything goes wrong and you could end up prosecuted ,regulation 510.3 requires that the installer takes into account the manufacturer's instructions so realy if you are in any doubt ask your self what will i tell the judge

 

[Rockingit]

Rockingit,
However, 7671 does guide us to Manuf' Instructions, so, if the Manuf' says no then no it is, we can't argue

Agreed. But at what point is this information conveyed? When I install a CU I am required to read the instructions, fair enough. But at what point does E&OE come into it? If it doesn't say at the time........

 

[Engineer54]

E54,
Yep it is tosh, but it is the makers protecting their income, they can so they will.
Trouble is over here the "regs" say we must abide by Manuf' instructions, so there is an impasse there.
I don't agree with it, but as yet I have not managed to find a suitable argument that will IMHO stand up in court.
I would personally have no issues with replacing superseded equipment either, but, this was said to illustrate the flaw in the argument.

As I have recently posted, and you should know well, building an assembly from CE marked kit does not automatically result in the assembly being CE marked.

So, yes I agree and IMHO also it is a flaw in the system.
I discussed this with several MCB & DB makers at Elexx recently however, they were keen to protect their revenue streams!

Standards surely, are to ensure conformity, ....not serve as manufacturers protecting their business!! There are more than a few manufactures instructions that i would be more than happy to stand up in a court and tear them apart. ...haha!!!

 

[netblindpaul]

Rockingit,
IT must be in the instructions, or their published literature as I understand it.

E54,
Yes, however, there are many ways of meeting standards, a small aside, however, if you look at the current batch of F1 cars, there are significant differences between the cars, however, they all meet the same prescriptive rule book that is Formula 1, because the rules are the sport if you get my drift.
Just look at the side pods on the McLaren & the Red Bull as a typical example.
Take the arc chute on a breaker, which way does it face, if one manufacturer, say maker 1, faces down and thus they allow more space at the bottom of their enclosure to allow for the ejected plasma and another's, say maker 2 faces up thus they allow more headroom in their enclosure.
In a polymer enclosure would both MCB's perform adequately in each others enclosures, possibly not.
So the standards are either not prescriptive enough, or they are too prescriptive...

 

[ackbarthestar]

johnboy6083,
This is why CE+CE does not equal CE!

That would be:
Chinese Equivalent + Chinese Export =Not Conformité Européenne or Compatibility Electromagnetique

 

[ackbarthestar]

I can't find anything here: CE mark - Wikipedia, the free encyclopedia that states for any given CE product category that components cannot be mixed.
Our book of guidance, BS7671 133,134,511 tells us nothing,except for 134 which states that equipment should be installed according to manufacturer's instructions.
Now look at the manufacturer's instructions and see what they say about installing mcbs in CCUs.
as an example:
One RCBO manufacturer states for the return of faulty RCBOs
"The waranty is withdrawn if:
after inspection by 'acompany' quality control department the device is found to be installed in a manner which is contrary to the IEE wiring regulations and accepted practice within the industry at the time of installation
and
the procedure for the return of goods has not been followed. The explanation of defect must be included when returning goods"

So we may have a circular argument.

 

[Rockingit]

Surely, if you follow the logic of N-B-P's argument to the fullest extent, at what point does MK say that you can't fit a Crabtree 13A plug into a Logic socket? (for example).

I think the issue is more one of politics than actual engineering danger. And that's just stupid.

 

[netblindpaul]

Rockingit,
BS1363 is designed to allow such interchanges though.
The point the manufacturers seem to have is that 60898 etc. is not designed to allow such interchanges for whatever reason.

 

[ackbarthestar]

FYI and out of indignant curiosity
BEAMA published a guide to low voltage circuit breakers to BS60898-1 ,-2 and 60947-1, where the quoted contributors are as follows:

Eaton,
Electrum
Hager
Legrand
MK
Moeller
Schneider
Siemens
Timeguard
Western Automation

I don't suppose these companies are under the same manufacturing umbrella? Of course they are not, but they are all singing from the same song sheet. Therefore its logical to suppose that they are all trying to conform to the same standard, as is the publication. The only differences are likely to be the mechanical connections.
If the din rails, the terminal holes, the bus bars are common to all the manufactured MCBs/RCBOs then all manufacturer's MCBs/RCBOs will be interchangeable.

 

[ackbarthestar]

Since I can't inspire any of you to grapple the carrot. I thought I'd argue the case against myself - play Devil's advocate, I think they call it

Here's a response I found lately

IET Forums - BEAMA Bulletin - Installing New MCBs Into Existing Distribution Boards

This appears definitive?

 

[netblindpaul]

The link to the BEAMA papers is here:
Technical BulletinsUnfortunately we will find it difficult to argue against this, however much we disagree.
I think it is just protectionism, however, we are a bit stuffed!

Just another cost to pass on to clients which the cowboys won't have or care about, so more work for them, less work for us again!

 

[Guest112]

Where did this information originate from about the testing being void if there are mixed breakers. Ive been doing testing recently and I have never heard of a mix of mcbs failing the tests, Is there referance to this in any regs or gn3 books,

I read above that there is a reg that says manufacturers instructions must be followed is that the only one it seems to me that manufacturers want to play the blame game and basically want to blame the spark who installed the mcbs or the last spark that tested the board????

 

[netblindpaul]

Where did this information originate from about the testing being void if there are mixed breakers. Ive been doing testing recently and I have never heard of a mix of mcbs failing the tests, Is there referance to this in any regs or gn3 books,

I read above that there is a reg that says manufacturers instructions must be followed is that the only one it seems to me that manufacturers want to play the blame game and basically want to blame the spark who installed the mcbs or the last spark that tested the board????

peter,
You have misinterpreted the "testing", this is NOT "OUR" testing but the manufacturers type testing to achieve approval of their breakers for sale.

 

[vernam616]

Interesting article on this very subject in the October 2011 issue of "Professional Electrician" magazine (the free one you find on the wholesalers counters)

Also states shouldnt be done, in my eyes its logic, lets face it you wouldnt have one size tyre on one side of your van and another of the other side would you?

Same as brakes you wouldnt fit brakes from a vauxhall chevette when you drive a ford escort

 

[IQ Electrical]

Interesting article on this very subject in the October 2011 issue of "Professional Electrician" magazine (the free one you find on the wholesalers counters)

Also states shouldnt be done, in my eyes its logic, lets face it you wouldnt have one size tyre on one side of your van and another of the other side would you?

Same as brakes you wouldnt fit brakes from a vauxhall chevette when you drive a ford escort

I must agree with vernam616, all this talk of 'standards' is irrelevant, if you take BS EN 60898 as an example, it doesn't specify sizes and shapes of devices, only operating characteristics of the devices so how can you just assume that the stringent tests applied in UK Annex ZA of BS 60947-3 will work across a broad range of manufacturers components, all of different physical sizes etc.?

Here's the Annex, the test is described within:

 

[netblindpaul]

IQ,

I agree, however, it would not take much to have the standard, standardised, I don't have a copy of 60898 to hand at the moment, but I will check to see what is says.
I am aware of the Annexe ZA stuff.
I do believe that if the breaker complies it should be OK to fit, but, it looks like this is dying of death!
I would like to have a chat over a beer or 2 with a couple of the manuf' staff to see what the gripes are.
I will try shortly if I can.