"Mike Harrison" wrote in message
...
On Tue, 30 Sep 2003 20:52:46 +0100, "Rich"
wrote:

Evening all, need some advice, I have got a 60amp supply to my garage
which
is 40mtr's from the house mains position the SWA is 16mm 2-core using the
wire armour as the earth which is connected to the house earth via a
60amp 1
way fuse box wired in to the out going meter tails via phase blocks, in
the
garage there is a 80amp 30mA RCD.Using an RCD tester the trip times are
well
under the 200ms max, think it was about 0.05ms time on fast trip but is
this
a true test in the event of someone coming in to contact with a live
wire,
i.e. doing an RCD test you test between live and the earth ( which goes
back
up to the house earth ) so would not simulate live to the ground of the
garage ???? is there another type of test you can do to simulate this.

Richard

RCDs sense imbalance in the live and neutral current, so it shouldn't
matter which earth the current
is leaking to.

& the armour is no longer no longer acceptable as an 'earth'
should be an internal conductor or an external (min) 10mm