LRod writes:


[...]

You trust a switch? Unplugging or installing and using a physical
disconnect is the only sure way (or popping the breaker at the panel).

The breaker is *also* a switch, albeit it should be a more trusty one
than an ordinary switch, with a larger distance between the contacts
in the off state.
Switches come in a number of patterns, which are more or less safe, i
_guess_, that those whicl allow you to apply a padlock are a safe to
use in such a case. Read in any case the specifications of the
switch, if it doesn't have any desist from using it: It will be crap.
--
Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
Phone: +49 228 73 2447 FAX ... 7869
Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23