Changing from fuses to MCBs in Memera 2000 consumer unit

[DEfusion]

In our new property we have a Memera 2000 AD consumer unit and it has glass fuses which you remove/replace by sliding out a plastic housing for each one.

I much prefer MCBs and wondered if replacing these is a job you can do yourself. All the circuits are fully labeled and it have RCD protection on one side. Assuming I can find the correct MCBs (any advice on the type would be appreciated) then isn't it just a matter of turning off the main and RCD protection switches and avoiding the incoming service cables?

Or is this a job best left to professionals, and if so what kind of cost would I expect to incur for a job like this?

 

[Iggifer]

The physical act of changing them is easy enough, it's just a case of undoing all the screws along the bottom to drop out the busbar, undo the screw at the top to remove the cable(s) unclipping the fuse carrier from the DIN rail with a flathead screwdriver and repeating in reverse for the MCB

There are other considerations that need to be taken into account that are probably beyond your knowledge such as disconnection times etc

Personally, so long as you've got an RCD I would be happy with fuses.

We all know fuses work each and every time, it's a piece of wire that blows, an MCB is a much more complicated piece of equipment, and whilst not unreliable, they can never be as reliable as a fuse.

 

[JohnW2]

...an MCB is a much more complicated piece of equipment, and whilst not unreliable, they can never be as reliable as a fuse.

Well, we hope that is the case. Given that it is to all intents and purposes impossible to test an in-service MCB, we really don't have a clue as to how reliable they are in service - we just 'hope'! Given that we know that RCDs (which we can test) sometimes 'stick', I think it would be a brave (wo)man who would be totally confident that this never happens with MCBs - at least, the magnetic part. Fuses, as you say, are essentially 'foolproof'.

Kind Regards, John

 

[mfarrow]

When you say 'glass fuses', I assume you know this but they have some writing on them, i.e. they aren't just clear?

If so, stick with the fuses, as they'll be very reliable, and leave a few spare around. You may even have a space to store the spares in the fuse holder.

MCBs have certain characteristics which can make them operate even if some downstream protection would have cleared the fault (i.e. a plugtop fuse). Although they are very good for adding individual RCD protection to for the circuit as a combined device (otherwise known as an RCBO).

If you have any of the non-RCD protected circuits with sockets on them, especially if downstairs, or a shower, then I would consider replacing these with RCBOs to give you the additional protection required when using portable equipment (stuff you plug in).