<!doctype html public "-//W3C//DTD W3 HTML//EN">
<html><head><style type="text/css"><!--
blockquote, dl, ul, ol, li { padding-top: 0 ; padding-bottom: 0 }
--></style><title>Re: [RE-wrenches] Fwd: Grounding on a
glacier??</title></head><body>
<div>At 15:33 -0700 24/7/09, toddcory@finestplanet.com wrote:</div>
<blockquote type="cite" cite><font face="Arial" size="+1">Hmmm, I
wonder how the birds can sit on those same HV wires and do just fine?
If a wire is not referenced to the ground you are standing on,
touching it would not give you a shock unless you were also in contact
with the other conductor it is referenced to.</font></blockquote>
<div><font face="Arial" size="+1"><br></font></div>
<div>It's a safety issue only when there is a fault. In the
event of a fault that connects a hot wire to the battery system then
the battery system will become hot. Making sure that neither
pole of the battery is grounded will not prevent this in fact it will
make it possible. If the HV system has a grounded conductor then
the other one will be hot and any associated wiring systems need to be
grounded for safety in case of contact.</div>
<div><br></div>
<div>At 15:48 -0700 24/7/09, toddcory@finestplanet.com wrote:</div>
<blockquote type="cite" cite><font face="Arial" size="+1"> A
single pole switch will stop the current regardless of whether one of
the conductors is referenced to ground or not.</font></blockquote>
<div><br></div>
<div>If one pole is neutral and the other is switched off then the
circuit is safe. But if the system is 'floating' and you only
turn off one pole then the circuit is still live. You have
stopped the current but you have not necessarily made it safe to work
on. If neither pole is grounded then both must be treated as
potentially hot. That's why it's actually more expensive to have
'ungrounded' systems. You will still need to have grounding
conductors for safety and you will need to double the number of fuses,
breakers and switch contacts.</div>
<x-sigsep><pre>--
</pre></x-sigsep>
<div>Hugh Piggott<br>
<br>
Scoraig Wind Electric<br>
Scotland<br>
http://www.scoraigwind.co.uk</div>
</body>
</html>