Three Bedroom Three Floor Town House.

[kai]

Three Bedroom Three Floor Town House.

I saw this house, of 1960's construction, strangely enough the mains intake service fuse block, has the main earth cable coming out of the right hand side of it, Did they have PME/TNCS earth all those years ago?

Checking the neighbours either side of it, also had PME/TNCS earthing.

On a three storey building, would it be better to run sub-mains to each floor, and route the circuits from each sub board, or trying to route everything from the original fusebox position in the entrance hallway?

It will have an 7.2kW Electric Showe , 7.2.kw Cooker, economy seven heating, 3kW immersion heater etc.

 

[RF Lighting]

Is it staying as a single dwelling or are you splitting it into three flats? If it staying as a single dwelling then just keep it as having one consumer unit feeding the whole installation. Are you sure the shower is 7.2kW? It sounds a bit on the small side to me. I am not sure wether PME was available around 1960, I would have expected a lead cable wrapped in steel and covered with horrid sticky tar soaked cloth stuff, with the earth taken from a clamp off the cable. It is possible that the DNO has replaced the supply cable and or service head.

 

[kai]

It will be staying as One Dwelling only, would Voltage Drop and EFLI issues come to light on the Ring Final Circuit for the top floor level? (Could wire the RFC in 6.0.sq.mm. cable, but would it fit in the socket terminals?).

 

[RF Lighting]

Do you know roughly the circuit length of the top floor ring? (Including legs to your CU)
6mm² would be a bit of a pig to terminate at the sockets, but if you have issues with EFLI and or volts drop then you could use 4mm² cable which is not too dificult to terminate, especially if you use a decent quality socket front such as MK

 

[cozycats]

socket terminals are designed 2x4mm max but if you consult the osg and circuit lengths it is unlikely above 2.5 required.

 

[plugwash]

MK claim 3x2.5mm or 3x4mm or 2x6mm will fit in thier terminals.

 

[RF Lighting]

you can fit four 2.5mm² cables at a push in an MK socket
Or so I'm told not that i've tried or owt

 

[Jaymack]

you can fit four 2.5mm² cables at a push in an MK socket
Or so I'm told not that i've tried or owt

Max Core Sizes for SO's
Clause 11.5 of BS1363-2 states:

"Line and neutral terminals in fixed socket-outlets shall permit the connection, without special preparation, of one, two or three 2.5 mm2 solid or stranded; or of one, or two 4 mm2 stranded conductors."

Do MK exceed this?

Jaymack

 

[plugwash]

first page of http://www.mkelectric.co.uk/PDF/technical/LOGIC_PLUS_tech.pdf claims

Terminal capacity:
Live, neutral & earth
3 x 2.5mm²
3 x 4mm²
2 x 6mm² (standard)

 

[Adam_151]

I've heard it claimed that while the socket outlets will stake 2x6mm² , the FCUs won't

Oh another point of note, but going off on a bit of a tangent, I do know that while a single 6mm² will fit in just about any socket, some people will record it as a deviation on a PIR as they are not designed for that, though I expect if it was a MK device and they had a copy of MK's specs, then they wouldn't be able to

 

[plugwash]

For MK FCUs

Terminal capacity:
Supply terminal: 2 x 6mm² stranded
2 x 4mm²
3 x 2.5mm²
Load terminals: 2 x 6mm² stranded
2 x 4mm²
3 x 2.5mm²

whether getting them in is easy or not is of course a different matter.