On Wed, 16 Sep 2009 16:09:50 +0100 someone who may be Geoff Mills
wrote this:-

Is it common practice to return the cable down the same conduit that
it came up in,

Yes.

Assuming metal conduit, if there is not a copper protective
conductor drawn into the conduit then you need to be particularly
careful about making proper joints to maintain the continuity of the
trunking which forms the protective conductor.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54