Earth entering house (for info)

[cemhlm]

In the cupboard where my electrical supply is metered etc., their is a thick black covered rod type "thing" coming up thro the floor clamped to the metal at the top of this rod as a clamp which has a cable running from it to a metal bar consisiting of 8 terminals. Just above where the clamp is attched to the "rod" it dissapears into into a sealed black unit, from which runs two thick grey cables they inturn go into the electric meter, and from the other side of the meter two thick cables then run to the fuse box.

Back to the metal bar there is another cable running from 1 of the terminals this also runs to the fuse box, is this the earth for the ring main etc?

There are 6 spare terminals on the metal bar, can they be used for example earthing a security light at my front door, my lighting circuit has only 2 wires L/N but the sec ligh requires and earth.

 

[JohnD]

A photograph would be a great help.

//www.diynot.com/forums/viewtopic.php?t=99672

also have a look at 23
//www.diynot.com/forums/viewtopic.php?p=141310#141310

 

[Adam_151]

Sorry, but I've got to correct some terminology here

their is a thick black covered rod type "thing" coming up thro the floor clamped to the metal at the top of this rod as a clamp which has a cable running from it

That sounds like its your service cable, most likely of lead and paper construction

to a metal bar consisiting of 8 terminals.

Thats the MET (Main Earth Terminal)

Just above where the clamp is attched to the "rod" it dissapears into into a sealed black unit

black unit = service head/ cutout

from which runs two thick grey cables they inturn go into the electric meter, and from the other side of the meter two thick cables then run to the fuse box.

Commonly called meter tails, or just tails

Back to the metal bar there is another cable running from 1 of the terminals this also runs to the fuse box, is this the earth for the ring main etc?

Earthing conductor - connects the MET to the earth bar in the CU, to which the individual CPCs for circuits are connected, there should also be some main equipotential bonding conductors attached to this MET... if they are absent then they need to be installed


Are you able to get a picture?, the clamp could be a bit dodgy, normally the DNO will sweat the earth to the lead sheath, but sometimes they do use special kind of clamps, the problem is that if someone has DIYed a connection to the sheath, then chances are a BS951 clamp has been mis-used (which causes problems, becuase it could slacken over time, and attempts to re-tighten could damge the cable and cause a big bang )

There are 6 spare terminals on the metal bar, can they be used for example earthing a security light at my front door, my lighting circuit has only 2 wires L/N but the sec ligh requires and earth.

Well done for not rushing ahead and installing it anyway , some would would , If your lighting circuit is missing a cpc (circuit protective conductor - earth wire) then really it needs re-wiring, it was installed before England won the world cup, so quite old If you installed a separate earth following the original circuit route, then this would be an inferior solution for not much less effort, and while it could go back to the MET, it would make more sense to connect back to the earth block in the CU
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[ban-all-sheds]

Back to the metal bar there is another cable running from 1 of the terminals this also runs to the fuse box, is this the earth for the ring main etc?

Do you have any earth cables running from your incoming water (and gas if you have it) pipes to the CU?

 

[cemhlm]

Sending photo via admindiy as the step by step guide doesnt work. No idea when/if it will appear.

 

[oharaf]

I;m feeling quite nervous about this fella

Never mind the state of his houses wiring!!!