Mixed brand MCBs and EICR coding

[JohnW2]

Stop commenting then!

From your viewpoint, probably the most important comment I've made, several pages back, was:

... having said all of that, and despite what BAS seems to think/imply, I would never 'advise' anyone to used mixed-make devices, and nor would I install a 'wrong make' one in anyone else's CU (other than as a temporary measure). However, as far as I am personally concerned (i.e. in relation to my own installation), I am far more concerned with such issues as how well conductors have been terminated in the devices than whether or not the devices are 'the right make' (assuming they 'fit' {again, in common sense terms, rather than stillp's 'micrometer' view})

Kind Regards, John

 

[kai]

One engineer said that "If the maximum prospective fault current at the board is less than the breaking capacity of ALL the breakers in that board, AND the board is fed from a suitable BS88 or similar HBC fuse then you can use any make of MCB you want, as long as it fits the space properly."

 

[JohnW2]

One engineer said that "If the maximum prospective fault current at the board is less than the breaking capacity of ALL the breakers in that board, AND the board is fed from a suitable BS88 or similar HBC fuse then you can use any make of MCB you want, as long as it fits the space properly."

Whether that is electrically reasonable or not, a mixture of MCBs of different makes would be non-compliant with BS7671 if it was a single-phase supply ≤100A to an installation which was "under the control of ordinary persons".

Kind Regards, John

 

[stillp]

One engineer said that "If the maximum prospective fault current at the board is less than the breaking capacity of ALL the breakers in that board, AND the board is fed from a suitable BS88 or similar HBC fuse then you can use any make of MCB you want, as long as it fits the space properly."

In that case he should not be calling himself an engineer.

 

[kai]

It's a major flaw in the din-rail-system standards - when the board manufacturers got around the table in the Eighties in order to draft the din standard, they forgot to finish it off - they agreed on the din-rail mount, and the aperture openings, unfortunately they failed to reach agreement on the busbar connections, which would have probably solved the problems.

 

[stillp]

What are you on about? There's no formal agreement on the position of the so-called DIN rail in DBOs, nor on the aperture openings.
Those rails are standardised in BS EN 60715:2001.

 

[kai]

That's probably why you find empty din-rail housings for sale, and I found that I can fit many makes of breaker into them - as long as I do not try to connect the busbar in.
The din-rail and openings/apertures line up fine though.

MK_WYLEX_FUSEBOX_HYBRID

• kai
• 21 Feb 2016

 

[stillp]

That's probably why you find empty din-rail housings for sale

What is? The mounting rail itself is standardised, none of the enclosure dimensions are.

 

[Risteard]

One engineer said that "If the maximum prospective fault current at the board is less than the breaking capacity of ALL the breakers in that board, AND the board is fed from a suitable BS88 or similar HBC fuse then you can use any make of MCB you want, as long as it fits the space properly."

What he is suggesting is that the type testing is not necessary then as you are not claiming compliance with the UK-only derogation in Annex ZA for the conditional rating of the protective devices.