V
Virtus Lucem
Hello Guys,
I have a question for you on metal conduit earthing systems. I've been asked to upgrade the CCU on my wife's grandpa's 2 bed flat (bit of a love job so I want to keep costs down). On inspection I've discovered it's an old Imperial metal earth conduit system. All the EFLI values are well within range for the 3036 fuses protecting it and the Zs at DB is 0.15. My main concern is the main earth and main bonding. The steel conduit supplying the main tails is used as the main earth, obviously this is fine and safe complying to the old regulations, but if I update the CCU to another metal CCU will the installation comply to the 17th using the steel conduit as the main earth? If I can what would I put on the certificate as to the size of earth?
It's a 5th floor flat and the conduit disappears into the concrete floor so running a 16mm earth from the supply isolator would definitely take some further investigation as I don't think I would get a 16mm down the conduit. Can I use the existing conduit and comply to regs or not?
Also there is not water or Gas bonding that I can see however there is continuity to the earth terminal and a nice low reading. how did they bond in the good old days? Luckily the gas meter is in the same cupboard as the CCU so I can easily run a 10mm to it however to the water inlet would again be more involved.
One more thing is the flat has an old warm air heating system do you know the likelihood of asbestos in the heating system?
Cheers!
I have a question for you on metal conduit earthing systems. I've been asked to upgrade the CCU on my wife's grandpa's 2 bed flat (bit of a love job so I want to keep costs down). On inspection I've discovered it's an old Imperial metal earth conduit system. All the EFLI values are well within range for the 3036 fuses protecting it and the Zs at DB is 0.15. My main concern is the main earth and main bonding. The steel conduit supplying the main tails is used as the main earth, obviously this is fine and safe complying to the old regulations, but if I update the CCU to another metal CCU will the installation comply to the 17th using the steel conduit as the main earth? If I can what would I put on the certificate as to the size of earth?
It's a 5th floor flat and the conduit disappears into the concrete floor so running a 16mm earth from the supply isolator would definitely take some further investigation as I don't think I would get a 16mm down the conduit. Can I use the existing conduit and comply to regs or not?
Also there is not water or Gas bonding that I can see however there is continuity to the earth terminal and a nice low reading. how did they bond in the good old days? Luckily the gas meter is in the same cupboard as the CCU so I can easily run a 10mm to it however to the water inlet would again be more involved.
One more thing is the flat has an old warm air heating system do you know the likelihood of asbestos in the heating system?
Cheers!
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