by sparx »
Mon Jun 18, 2007 10:58 pm
Hi, first thing is visual checks as bond to water must be in 10mm2 cable your side of main water stop cock within 300mm of it so should be obvious, likewise with gas , must be within 300mm of your side of meter after flex pipe b4 any branch or tee, unless external meter box, in which case can be within 300mm of point of entry to building . Also in 10mm2 conductor. If you can't see it it aint there!
If you believe it to be earthed but not visible then you must carry out a 'bond-test' using a meter capable of passing several Amps (4.5-25) purpose made for the job, an ordinary multi-meter won't do i'm afraid as it may see an earth path but the route may not be capable of carrying enough power to trip a fault current.
The other thing is to look at cables leaving your fuse board, there should be a main earth in plus 1 or 2 large outgoing earth wires seperate from those in twin & earth circuit cables, if not you have a prob.
regards SPARX