Correct cabling for flat consumer unit supplies

[Deleted member 26818]

you can't run plastic gas pipes in a building as it would be catastrophic in a fire. If the gas is run in plastic externaly it has to change to be being metallic before it enters the building. The yellow plastic pipe feeding external gas meters is not allowed to be exposed so again needs to change to be being metallic before it comes out of the ground.....in other words it's pretty hard to get away with not bonding gas.

Hmm, seen quite a few yellow plastic pipes connected to internal meters. Have even seen them bonded.
Yes the internal pipework has to be metal for gas, that is if there is gas.
The internal pipework for Water can be either metal, plastic or a mixture of both.

 

[Ian1981]

Do you mean were they connect to the meter externally?
Because where the gas enters the building is always in copper as it has to be , at least that’s what I’ve always experienced
I suppose the question is that the pipework entering the property, is it extraneous?

 

[Deleted member 26818]

Doesn’t have to be copper where it enters a building.

 

[Ian1981]

Doesn’t have to be copper where it enters a building.

Like I say I’m not a gas engineer but I’ve never seen plastic gas pipes enter a building from the outside

 

[Leesparkykent]

Would you need a switch fuse after the BEMCO or ryefield as you call it or just from that via meter and double pole isolator as you would have potential say 2 60 amp fuses in series and it’s a different set up to say a house where the tails are greater than 3 meters?

Tell you the truth Ian we just install switch fuses but reading the info the DNO supply you with, you could use a DP switch as you have the fuse in the Ryefield/BEMCO board. 9/10 times the flats we do a 60A supply is adequate so 100A fuses in Ryefield and 60A fuses in the switch fuses. Using the rule of thumb of x 1.6 for discrimination between upstream and downstream fuses of the same type then discrimination is just about achieved. I prefer it this way if it's possible so if there was a fault, the fuse in the switch fuse goes and an electrician can replace it rather than entering a sealed Ryefield which is frowned upon by whoever sealed it.

 

[Deleted member 26818]

I have seen yellow plastic gas pipes in cellars, have seen them enter buildings above head height (though outside on the external wall, the plastic pipe was inside metal tube.

 

[Ian1981]

Tell you the truth Ian we just install switch fuses but reading the info the DNO supply you with, you could use a DP switch as you have the fuse in the Ryefield/BEMCO board. 9/10 times the flats we do a 60A supply is adequate so 100A fuses in Ryefield and 60A fuses in the switch fuses. Using the rule of thumb of x 1.6 for discrimination between upstream and downstream fuses of the same type the discrimination is just about achieved. I prefer it this way if it's possible so if there was a fault, the fuse in the switch fuse goes and an electrician can replace it rather than entering a sealed Ryefield.

That’s a good way of looking at it lee.
Just we’ve done a few buildings/flats with BEMCOs and then double pole switches to flats as we consulted the DNO and they saw no problem with it and the BEMCO boards were fed from fused isolators anyway and via a single source of isolation.
We only had 63 amp fuses in the BEMCOs as the supply to the 1 bedroom flats were only 16mm swa so we saw no point in having 2x 63 amp fuses in series.

 

[Leesparkykent]

Plastic pipe for gas is not allowed to be used within a building at all...The options are copper, barrel or tracpipe. Externally plastic pipe is allowed to be used but not exposed so it has to change to one of the pipes mentioned above or be covered so it's not exposed.