help on sub mains.

[jl-heating]

pic for kieth to view on Flickr - Photo Sharing!

talk me through this guys,.

(ignore the shoddy work this is not about that or the bare cables in the consumer.)

how on earth can i let this go, 10mm T&E tails and the 4mm cpc for main earth.

supervisor on site turned the consumer on after i condemned it and shut it down..

all i was told is its a sub main there fore ok. ?

 

[betty swollocks]

cpc looks more like 10mm to me

10mm tails for a submain cu is fine depending on the outgoing load

only looks like 1 32A mcb and 1 6/20A? rcbo being used so 10mm would be fine for that

looks fine for a cu wired in the dark

not ideal but what job ever is?

 

[jl-heating]

the 10 mm are gas and water.

its a 1 bed flat, and a 9 Kw shower is on the circuit to . god only knows why when there is a combi in the flat .

 

[maccarooni]

the 10 mm are gas and water. its a 1 bed flat, and a 9 Kw shower is on the circuit to . god only knows why when there is a combi in the flat .

JL

If there are protective bonding conductors ie 10mm for gas / water. In the event of a fault, the 4mm won't carry the required fault current. As a MINIMUM, I would bring across a seperate 10mm earth to the new board. If it cant be brought from the existing supply ( where the sub main comes from) would it be possible to whack an earth stake in?

Macca

Guiness DrinkGuiness DrinkGuiness Drink

 

[jl-heating]

nothing to do with me now its more for a reference for future work.

i was told the 10mm gas/water is fine for the fault current and he even gave me a figure to work to . LOL !!.

he was not interested in the fact that the whole property was in fact protected by a 4 mm earth,

cables out of the safe zones,

main bonds not connected,

A spike would of sorted it if in fact he thought there was a problem,

never mind the 10mm tails.

supervisor over rode my decision , i was in the van before he closed his lips. lol.

the whole flat was plastered and decorated and all the cable was under the boards in the ceiling.

they did not want me throwing a spanner in the works when the last 3 blocks were done the same. 12 per block.

Its a sub main .. so its fine.. zzzzzzzzzzzz

 

[Apache]

Its a sub main .. so its fine.. zzzzzzzzzzzz

................until the 4mm earth melts

 

[Flying Scotsman]

yes thats when things will get messy,

very

 

[davetheglitz]

I'm making some assumptions here - so bear with me if I've got it wrong!

Regarding the earth I'm assuming the 4mm is what is fed up to a flat as a sub main.

I find this a very difficult area. If the is was one single property and the incoming gas and water were bonded correctly at the incomer then everyone would be happy (assuming this is the case and we are talking about a flat).

If the property was split into flats does this electrically change what was acceptable before?

Should each individual flat have the bonding - or if not what is the legal recourse if the bonding to the property is compromised without the flat owners knowledge?

Don't know the legal answers - but to my mind if the system works as a single property then you should pass it - but make sure you voice your concerns on the certificate to cover your back. You are only certifying things on the day. No-one would think of questioning this for an MOT - the same must apply to inspection and testing!

Hope this helps

Dave

 

[jl-heating]

as far as i am aware you cant depend on the water and gas as a fault path.

the supervisor on site said you could, he even gave me a value to work to.

the flats are a block of 12.

the flats were completely re wired so i had no need to certify anything. i was connecting to a existing spur so was just visually checking the circuit i was on,

ieolarity,pfc and Ze and earthing arrangements etc.

i pulled the plug on the installation and lettered it. spoke to the supervisor on site and my immediate supervisor, my supervisor said it was wrong and spok to the main contractors, they said not to worry it was fine and they would sort it from here on .

i mainly wanted to clarify this for future reference.

this is were you boys come in .