one water supply , two incomers

[razz]

hello all , i work in a large school that is rather old , with many buildings oh all shapes and sizes , for a while now i`ve been trying to locate the incoming water service so that i can take an earth connection to it , i`ve now been given plans from 1960 which shows where they are , but i`ve now found that we have one incoming water , split into two different buildings , which in turn have two mains incomers , both tn-s , my head says , bring an earth from both of these to the one water , does anyone agree or disagree , cheers

 

[rryles]

I'd be inclined to treat each building separately. i.e. bond the supply earth to the water as it enters the building.

 

[NMc]

Each building must be treating individual and the supply needs to be bonding to the other services at the point (points if more that one) of entry to the building. All services entering a building are seperate

If the individual building has 2 supplies to that building, each supply must be treated individually seperate and both supplies need to be bonded to the water at the point(s) of entry to that building

Happy bonding

 

[razz]

cheers chaps , i`ll bond the water as it enters each building to the nearest mains incomer

 

[Engineer54]

Ady1,

If you have 2 incoming electrical supplies in the same building, and your only bonding to one of those supplies MET, then you need to link the other supplies MET to the supply that has the bonding. Are you sure they are 2 separate supplies and not a looped supply??

 

[razz]

yep , its two supplies coming from completely different directions , i`d say about 200m apart ,we had a power failure on one of the phases which knocked out certain areas , when i question`d EDF or whatever they are called , he informed me that the two incomers are from seperate substations , the building or buildings are linked all the way ( not separate ) and are also linked by heating pipes , sorry i`m not to good at describing , but i`ve spoke to local nic lads and they say bond the lot , but i will just say , i`ve got the plans of the pipe location , but i`m yet to locate then

 

[Engineer54]

ady1

Then you need to bond each electrical supply separately, not much else you can do in a situation such as yours...

The heating pipes will also need bonding, i take it they derive from a substantial boiler installation?? Does the boiler(s) also supply the hot water requirements to the building?? Also does the heating pipes enter and depart the building, supplying other buildings with heating?? If so, they need to be bonded at both locations, as they enter and leave the building. Same goes with the hot water supply pipes if any. Any Other services such as air conditioning etc in the building??

 

[razz]

hello there , thanks for replying , yep the heating boilers are in one building , then they go off and heat 6 others , the hot water boiler is in another building , it all crosses each other . i have put in quite a bit of cross bonding as they pass each other and will attempt in the future to get as many main earths in as possible , we do have air con , but its only into local rooms