According to :
On Fri, 9 Nov 2007 05:40:42 -0500, "StarMan"
wrote:

Anyone have any good wiring links?

Doing a Google search returns to much junk. I wonder if there are any tip
pages people know about for this which are QUALITY, to save hours of time
going through bad Google results?

The short answer is probably "you can't do it without a service
upgrade". If you have a spare "pullout" it is easy but that is unusual
on an old fuse panel.

I think "pullouts" in this context are double fuse blocks that plug into
the fuse panel backplane. Those designed for a 240V circuit have hinged
interlocking covers on them on them that prevent the fuses being
unscrewed without removing the whole "pullout", so both sides of the
circuit are dead. The fuses in pullouts designed for 120V circuits can
simply be unscrewed without removing the block, and these blocks are
intended to be left in the panel more-or-less permanently.

We kept some spares of both types when we wired a cottage back
in the early 70's ;-)

If you don't have a spare, it's still usually possible to obtain
one - either at a proper "electrical supply" place, or at fleamarkets.

Not all fuse panel types have pullouts, and those that do don't
physically _have_ to have "interlocking" pullouts installed for 240V.

Putting 240V into a panel without an interlock of some sort between
the legs is _usually_ a code violation. Heck, an anal inspector
might even insist on upgrading to circuit breakers.

If you want to do this and stay code-legal, best to consult
with a local inspector or an electrician. Regardless of whether
you want to keep this code-legal, the fact that you're asking
this question at all, suggests you should engage the aid of
an electrician.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.