Earthing question again!!!

[andemz]

At the moment our current earthing setup is from an earth rod to consumer then from consumer to around the house. I think this is right but i haven't looked if between the earth rod or the consumer unit the wire connects to anywhere else... I'm not really wanting to know about that part at the moment. I'll come to this in another post.

My question is this: My consumer unit has 16 earth terminals, it then has 1 terminal that has the earth sign underneath and then 2 terminals that say bond.

Would i be right in saying that the incoming 16 mm wire from the earth rod or wherever goes to the terminal which has the earth mark and then the bond terminals are used for earthing the house.

I will like all of my electrics be getting a sparky in but i am trying to understand this process.

Would it then be from the bond terminals to take 10mm Single Copper cable from your earth block to your incoming gas pipe, 10mm Single Copper cable from your earth block to your main water intake?

I'm confused as i thought that you could link the cables from pipe to pipe. If i can't that's my 3 spare terminals gone. or

Could you then take 10mm of earth wire from the terminal which has the earth mark bearing in mind it is where the other earth wire comes in from the rod and then go around the house earthing and supplementry bonding.

I'm really confused can anybody help. Here is a pic of my consumer Unit I've posted before on this topic but didn't really get to grips with it.

 

[securespark]

As you say, you're getting a spark in. Ask him or see what he has done when he's finished.

 

[andemz]

Just thought i'd ask the community first, to impart some free knowledge!

 

[securespark]

Not being awkward, but remind me what the responses were in your last attempt to post this subject - I can't remember what people said.

 

[dw3101]

Ive seen it done where people bring 16mm into the CU and then 10mm from the bond terminals to gas and water.

I prefer to fit a block similar to REC' and bring 16mm to that and then bond from there and run 16 to CU..

REC's normally fit one on PME installations as the bond / cross connect the outer of the cable on some installs.

AFAIK, its their resposibility to provide an earth connection, and its your resposibility to provide one until you ask them to.. (cant remember the response I got when I asked for a cut out changing from a non earthed metal one and asked for a PME installation.

David

 

[ban-all-sheds]

My question is this: My consumer unit has 16 earth terminals, it then has 1 terminal that has the earth sign underneath and then 2 terminals that say bond.

Would i be right in saying that the incoming 16 mm wire from the earth rod or wherever goes to the terminal which has the earth mark and then the bond terminals are used for earthing the house.

You could do that or you could take the connection from the earth rod to an earth block like these:

And from there to the CU and the pipes that need bonding - see Fig 4c in the OSG.

Would it then be from the bond terminals to take 10mm Single Copper cable from your earth block to your incoming gas pipe, 10mm Single Copper cable from your earth block to your main water intake?

Yes - although with a TT installation they only need to be 6mm², but bigger won't hurt.

I'm confused as i thought that you could link the cables from pipe to pipe. If i can't that's my 3 spare terminals gone. or

Yes, you can, but the cable must be continuous, i.e. you have to remove a section of insulation but not cut the cable, like this:

And 3 terminals is all most people need - the earth from the MET, and outgoing equipotential bonding conductors for the water and the gas.

Could you then take 10mm of earth wire from the terminal which has the earth mark bearing in mind it is where the other earth wire comes in from the rod and then go around the house earthing and supplementry bonding.

Not sure what you mean by that - the main bonding conductors run to the incoming service pipes:

and there they stop - you do not go around the house with them...

I'm really confused can anybody help. Here is a pic of my consumer Unit I've posted before on this topic but didn't really get to grips with it.
http://imagehost.darkernet.co.uk/i/consumer.jpg[/QUOTE]
That board is not suitable, as it stands, for a TT installation, as the main incomer is just a switch - it should be a 100mA time-delayed RCD....

 

[andemz]

Thanks b-a-s, you've really helped me to understand it better than i did before.

That board is not suitable, as it stands, for a TT installation, as the main incomer is just a switch - it should be a 100mA time-delayed RCD....

Yes i found this out about 3 weeks ago when i went down to an electrical store. I have purchased a time delayed one.

Just one point, the diagram really makes things clear. Are you saying that you can come of one of the earth bond terminals and earth both water and gas as long as it is continious, earth clips etc.

So Earth from the MET, 1 terminal for bond gas and water mains and then the other terminal for all other earth bonding, i.e combi boiler, radiators, bathroom pipes, rads and all fittings etc.

Have i got it right?

 

[Damocles]

No, you havn't. There are holes provided in case you need them, not necessarily for anything special.

The main bonding is from your main earth terminal to each place a supply pipe comes into the house. Then there is supplementary bonding in places like bathrooms. This is within the room concerned and does not need to go back to the main earth point. Generally it is connected to the main earth via the earth within any cable going to that room (e.g. inside the lighting power cable)