MK mcbs

[hard-work]

How backwardly compatible are MK mcb's? Neighbour has an MK CU with mcb's that was fitted in the mid 1980s. He has spare slots, and may need another circuit. Would a modern MK mcb fit? Anyone had experience of this?

He does not have the money for a new CU.

 

[flameport]

MCBs from that era are obsolete. There was a conversion kit which allowed either one or two of a later style to be installed in some limited circumstances, but that and the breakers used with it are no longer available.
The modern range is totally incompatible.

 

[SUNRAY]

How backwardly compatible are MK mcb's? Neighbour has an MK CU with mcb's that was fitted in the mid 1980s. He has spare slots, and may need another circuit. Would a modern MK mcb fit? Anyone had experience of this?

He does not have the money for a new CU.

Picture?

 

[hard-work]

Picture?

He is away for two weeks so can't take a picture. But from memory it looked similar to this. The protruding squared off part on the front I think was coloured black. I never saw them with the CU cover off.

 

[hard-work]

I saw these are available on ebay but used. Used old mcb's must be on their last legs.

 

[Taylortwocities]

If he has a spare slot, and it is a new circuit, it is important to know what the circuit is for.

A new circuit will need to meet today's regulations and, in most cases, that circuit will need RCD-protection. That is something that his existing CU may not have. Does it?

 

[SUNRAY]

He is away for two weeks so can't take a picture. But from memory it looked similar to this. The protruding squared off part on the front I think was coloured black. I never saw them with the CU cover off.

I don't know if I've seen that style of MK in black and I know I don't have any.
I have a habit of keeping old MCB's if I know their history. Just because they are old it doesn't mean they are knackered, but whether I'd trust all I see on ebay is a different matter.

Double check when he gets back.

 

[Taylortwocities]

Maybe it’s the old Dorman Smith breakers and not MK at all.
Pic needed

 

[AndyPRK]

I saw these are available on ebay but used. Used old mcb's must be on their last legs.

Just like the rest of the ones in your mates CU

So, QED, he needs a new CU then ??!

 

[hard-work]

If he has a spare slot, and it is a new circuit, it is important to know what the circuit is for.

A new circuit will need to meet today's regulations and, in most cases, that circuit will need RCD-protection. That is something that his existing CU may not have. Does it?

RCD? That old? No. It may have a ELCB. Will have to look when he gets back. A new circuit on an exiting CU and installation needs RCD? The new circuit will only be 6A supplying double insulated data equipement.

 

[hard-work]

Maybe it’s the old Dorman Smith breakers and not MK at all.
Pic needed

Definitely MK.

 

[hard-work]

A new CU with an RCD will need the earthing sorted. One earth cable from CU to pipe near water tap and another from the CU to the inlet pipe of the gas meter.

He aims to replace the CU in the next few years when he can stomach the mess and finances. It has worked faultlessly for over 30 years. He see no reason to rush.

 

[bernardgreen]

One earth cable from CU to pipe near water tap and another from the CU to the inlet pipe of the gas meter.

It is bonding not earthing , the connections are made as close as possible to the point of entry into the building, not "near the water tap"

 

[Taylortwocities]

RCD? That old? No. It may have a ELCB. Will have to look when he gets back. A new circuit on an exiting CU and installation needs RCD? The new circuit will only be 6A supplying double insulated data equipement.

I have seen many older CUs provided with an external RCD. Perhsps there is one. We cannot guess.
What has 6amp to do with anything? It doesn’t matter if the new circuit only provides power for one tiny lamp at the top of a Christmas tree, if the wiring is concealed, or has a socket then an RCD will be required.

 

[SUNRAY]

Maybe it’s the old Dorman Smith breakers and not MK at all.
Pic needed

That's what I wonder, as I said I don't recall seeing black (or brown) MK's I think I may have a small board's worth of DS's