On Wed, 05 Sep 2012 16:20:40 -0500, Pete Keillor
wrote:

On Wed, 05 Sep 2012 15:25:34 -0500, Jon Elson
wrote:

Ignoramus29252 wrote:

``There is no such voltage as 460 Single Phase. 460 volts is Three Phase''
While single-phase 460 V feeds are a bit rare, many welders definitely
are wired for 460 and only use one phase. I can imagine big industrial
ovens might also run off single-phase, as well as spot welders.

Jon
Big ovens I used or had that needed more than 208V were usually three
phase. Easy enough to do because they usually had multiples of three
elements. It needed appropriate care if replacing an element, but our
electrical folks were used to three phase and its hazards.

That's my experience. Even smaller plastics machines usually have
3-phase sets of heaters (most of the power consumption is the heaters
and the motor). The controls stuff could run off a single phase,
though I've seen a 3phase transformer to supply 24V for the controls
on a Battenfeld.