Fitting back boxes and cabling new extension

[oly]

Thinking to use 35mm back boxes set into the blocks, but can I simply run cables on the surface of blocks covered in plastic or metal channelling? Or do I need to chase out the walls?

Walls will be conventionally plastered.

 

[JohnW2]

... can I simply run cables on the surface of blocks covered in plastic or metal channelling? Or do I need to chase out the walls? ... Walls will be conventionally plastered.

Provided there is going to be a reasonable thickness of plaster (otherwise plaster may crack over cable runs), just clipped onto the surface of blocks ought to be adequate - covering with metal or plastic is not necessary unless you want to do it to protect cables from the plasterer's trowel!

Since the cables will clearly be buried less than 50mm deep, they will need to be RCD protected and run in 'safe zones' - are you familiar with them?

You may well get some comments about the bureaucratic aspects of this work.

Kind Regards, John

 

[oly]

... can I simply run cables on the surface of blocks covered in plastic or metal channelling? Or do I need to chase out the walls? ... Walls will be conventionally plastered.

Provided there is going to be a reasonable thickness of plaster, just clipped onto the surface of blocks ought to be adequate - covering with metal or plastic is not necessary unless you want to do it to protect cables from the plasterer's trowel!

Since the cables will clearly be buried less than 50mm deep, they will need to be RCD protected and run in 'safe zones' - are you familiar with them?

You may well get some comments about the bureaucratic aspects of this work.

Kind Regards, John

Thanks John, it will be joined into 30A existing ring circuit which goes back to the MK Sentry consumer unit with individual trip fuses.

It is a straight replacement of the exist kitchen power, plus adding three new sockets into the new dining area.

I have read about the safe zones but in the kitchen the power will come down all along the wall so I can protect with channelling there?

 

[JohnW2]

Thanks John, it will be joined into 32A existing ring circuit which goes back to the MK Sentry consumer unit with individual trip fuses. It is a straight replacement of the exist kitchen power, plus adding three new sockets into the new dining area.

Any new buried cables and any new sockets are required to have RCD protection. Is the circuit in question protected by an RCD(a wide device with a test button) in your consumer unit? If all the work consists of an extension of an existing circuit, it shoud not be 'notifiable' work.

I have read about the safe zones but in the kitchen the power will come down all along the wall so I can protect with channelling there?

If cables were buried (<50mm deep) and not in 'safe zones' then protecting them with 'channelling would not be adequate - you would either have to use special cable or else run the cables in earthed steel conduit. Perhaps you could explain more about "power coming down all along the wall"? Each socket creates safe zones horizontally and vertically aligned with them - so if a cable ran vertically down a wall into a socket, it would probably be in a safe zone.

Kind Regards, John

 

[oly]

Thanks John, it will be joined into 32A existing ring circuit which goes back to the MK Sentry consumer unit with individual trip fuses. It is a straight replacement of the exist kitchen power, plus adding three new sockets into the new dining area.

Any new buried cables and any new sockets are required to have RCD protection. Is the circuit in question protected by an RCD(a wide device with a test button) in your consumer unit? If all the work consists of an extension of an existing circuit, it shoud not be 'notifiable' work.

I have read about the safe zones but in the kitchen the power will come down all along the wall so I can protect with channelling there?

If cables were buried (<50mm deep) and not in 'safe zones' then protecting them with 'channelling would not be adequate - you would either have to use special cable or else run the cables in earthed steel conduit. Perhaps you could explain more about "power coming down all along the wall"? Each socket creates safe zones horizontally and vertically aligned with them - so if a cable ran vertically down a wall into a socket, it would probably be in a safe zone.

Kind Regards, John

Thanks again John.

No, I don't have RCD protection to the kitchen circuit.

The kitchen will have about 6 sockets where I plan to bring each's cable down from the ceiling vertically.

 

[JohnW2]

Thanks again John. No, I don't have RCD protection to the kitchen circuit.

Well, as I said, any new buried wiring, and any new sockets, would not be compliant with the regulations unless the circuit is RCD protected.

The kitchen will have about 6 sockets where I plan to bring each's cable down from the ceiling vertically.

If each cable remains within the zone vertically above the socket it supplies, that would be in a safe zone. However, if these sockets are all on the same ring, that would seem a very inefficient way of doing things. It is normally/often possible to bring a cable down to the first socket, wire each socket to the next (in the horizontal safe zones created by the sockets) and then take another vertical cable up from the final socket. However, if there are several different (non-joining) walls concerned, that may not be possible.

Kind Regards, John