Old MK Sentry MCB Replacement.

9 Oct 2007
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Tyne and Wear
United Kingdom
Hello all, i've replaced the shower + cabling in my house and i'm looking to uprate my MCB accordingly. I have an old MK board with Sentry MCB's and I need a 40 or 45 amp MCB to replace the old 30 amp.

The board is marked up as MK LN 5612 - 12 module. The breakers are rail mounted and the busbar is on the lower-front side of the MCB's

I know that you can't get these breakers anymore, but i've read on the net that Siemens and Hager do some that will fit. I've looked on 'The Fuse Company' website and their Siemens ones look identical.

Can anyone confirm this or any other help is gratefully appreciated.

I don't want to replace the whole board if I can help it.
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Thats the retro fit kit I offered him over on Screwy.

The MCB's in the second post will not fit.

Siemens breakers will.
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I do not think that you should mix the breakers, ither use the original ones (if you can find them or change the whole unit, because it something will go wrong the manufacturer will not accept liability and the insurance will not pay.. (I know they never do :( )
I don't see how you could consider using new MK breakers in an old MK box by using MKs own retrofit kit to be a non manufacturer approved setup.
I don't see the problem with using MKs own adaptor kit, however to fit a Siemens breaker to an MK CU means it is only a partially type tested assembly.

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