Bit of help with a TT installation please...

[timo1]

Hi, i'd appreciate a bit of help with this one if poss. Went to look at a job on a TT installation, property was a single story bungalow and has since been developed with another floor. As usual everything has been immaculately decorated, floors laid etc..and no thought given to the electrical services!! New owner is very realistic and happy to upgrade bonding, along with a decent bit of extra work.

I have checked and there is a 16mm earth from the earth stake/rod outside which goes directly into the C/U. there is no bonding present on either the water or gas. C/U is in the middle of the house, gas is positioned on the outside wall about 5 - 10 metres from the stake.

Ideally I would like to run bonding from the gas and water to the C/U but this is not an option, I'm all for a challenge but the route has me beat.

One solution I thought of would be to create a MET near the gas position and join the main earth and gas/water together, possibly in a weatherproof enclosure, obviously clearly labelled at source and at C/U. Property is RCD protected also.

Not ideal I know, looked at regs and can't see anything directly against it, any thoughts? Thanks in advance.

 

[Engineer54]

I can't think of a reason off hand why such a layout wouldn't conform or more importantly serve it's purpose!! Though i would definitely push the owner to swop-out the existing MCB's for RCBO'S on this TT system....

 

[Spudnik]

I dont see any reason why not.

Just make sure its noted on the certificate, and a suitably positioned notice stuck to the CU informing anyone that may need to know, where it is.

 

[chris123]

I can't see what the fuss is, it's just an met, earthing conductor connects the electrode to the met, services connected to the met via bonding , exposed conductive parts connected via cpc. Cpc to cu needs sizing based on largest fault current, if combined also needs to meet bonding requirements.

 

[spark 68]

I can't see what the fuss is, it's just an met, .

Because it is not usually done this way on domestic properties, and as the regs can be a minefield the op was just asking for opinions, which is always better to discuss and check these things.

As Glenn pointed out, some people don't think 'outside of the box', and others either believe myths or follow the regs blindly without thinking what the intention or reason for the reg was in the first place.

Some of this is down to college lecturers who just rinse and repeat the same regs/course over and over again without seeing the bigger picture.

Not a dig btw, an explanation.

And Welcome to the forum :waving:

 

[GLENNSPARK]

Hi Sedgy, I understand your reservations but I dont/cant walk away from work, especially as the customer isnt refusing the extra work, its just that I cannot get the bonding back to the C/U, sounds weak I know but you have to take my word for it. In fact it could even be why there is no bonding perhaps. I cant think of a reason why it would be unsafe?

Timo,....whats weak about looking and thinking about how to get round a problem?...as you have clearly done here?

 

[Edd]

seen it many times on TN system's with the meter box out the front of the house and the MET in there, all bonding taken from said MET and seprate SWA taken off to consumer unit in middle of house. Cant see any reason for it to be any diffrent on a TT system.

Ops just re reade OP, slightly diffrent set up. but still cant see any problem with it as long as its all labled corectly

 

[telectrix]

think a lot of us sometimes think that if it's not in the regs. we can't do it. the fact is.. if it's not in the regs., that means there's no reason why we can't do it. i.e. nothing in the regs. forbids it.

 

[timo1]

Thanks everyone, great to get different opinions and experiences. Much appreciated and the reason why this forum is so good. Thanks again.