Flats with 10mm twin and earth

[dokkan1080]

Seen loads of flats are fed from a 60amp isolator in 10mm twin and earth?

don't they need to be 16mm tails and at least a 10mm earth?

or is it just down to the adiabatic?

 

[James]

What does the cable rating say for the installation method?

 

[Dave OCD]

Are you certain that the sub mains you've seen aren't 16mm rather than 10mm ? They do look quite similar but 16mm would be far more common.

 

[dokkan1080]

Are you certain that the sub mains you've seen aren't 16mm rather than 10mm ? They do look quite similar but 16mm would be far more common

Are you certain that the sub mains you've seen aren't 16mm rather than 10mm ? They do look quite similar but 16mm would be far more common.

My bad i meant 16mm twin and earth but still the earth is only 6mm?

 

[dokkan1080]

Its the same in my flat 16 mm twin 6mm earth

The bonding conductors are bigger than the 6mm earth

 

[Dave OCD]

Ah ok, it depends on what the bonding requirements are, and the earthing arrangement. If, for example the incoming water was plastic and there was no gas supply then the 6mm CPC would be perfectly adequate.

 

[dokkan1080]

Ah ok, it depends on what the bonding requirements are, and the earthing arrangement. If, for example the incoming water was plastic and there was no gas supply then the 6mm CPC would be perfectly adequate.

The gas and water are both 6mm but some one has also run 10mm to them no idea when that was.

Main earth is 6mm from the 16mm twin.

If I wanted the board changed would I need to have a 16mm earth run?

A new earth could be run easy straight out the wall and down to where the main intake is in conduit or something.

 

[dokkan1080]

Its the same in my flat 16 mm twin 6mm earth

The bonding conductors are bigger than the 6mm earth

If method A 61 amps?

 

[dokkan1080]

What does the cable rating say for the installation method?

earth

If method A 61 amps?

 

[Dave OCD]

If the supply is TNCS then yes you'd have to run an additional 10 or 16mm earth with a CU upgrade -assuming of course that the water and gas pipework is extraneous and actually needs bonding ? Whoever upgraded the bonding without paying attention to the main earth didn't really have a grasp of the requirements IMO.

 

[dokkan1080]

If the supply is TNCS then yes you'd have to run an additional 10 or 16mm earth with a CU upgrade -assuming of course that the water and gas pipework is extraneous and actually needs bonding ? Whoever upgraded the bonding without paying attention to the main earth didn't really have a grasp of the requirements IMO.

Not sure if its tncs but its to cold to go have a look...0.0

So if I get a 16mm main earth in leaving the new 10mm bonding and the old 6mm bonding on the gas and water would be okay?

Would the old 6mm earth from the twin and earth thats acting as the main earth from the met to the cu need to be disconnected or could it just be left in as well?

 

[Dave OCD]

You could just run a 10mm and leave the sub main cpc connected , the bonding appears OTT but that's fine too.

 

[dokkan1080]

You could just run a 10mm and leave the sub main cpc connected , the bonding appears OTT but that's fine too.

Ah gotcha :3

So leave all the bonding connected 10mm and 6mm

Leave the current 6mm earthing conductor connected and the new proposed 16mm or a 10mm earthing conductor connected as well.

My only thinking is if its in even if its over the top I won't have to worry about having to put new cables in at some time later on ?

 

[cliffed]

We’ve actually added 16mm earth cable to the T&E ,on flats we’ve tested.
The 10mm & earth is ok for a Distribution circuit,it’s a composite cable so the earth’s always smaller,worked out by calculation
The bonding should be appropriate to the supply 10mm if TNCS, so in this case back to the MET wherever that maybe.

 

[dokkan1080]

We’ve actually added 16mm earth cable to the T&E ,on flats we’ve tested.
The 10mm & earth is ok for a Distribution circuit,it’s a composite cable so the earth’s always smaller,worked out by calculation
The bonding should be appropriate to the supply 10mm if TNCS, so in this case back to the MET wherever that maybe.

What would be different if it was tns?

So if a 16mm earth is added from the met to cu you can run the 10mm bonding back to the cu earth bar as opposed to the met