Re: [CAD_CAM_EDM_DRO] Single phase mains

Bill Darby wrote:

> My question is, could this unit be connected to single phase mains and
> drive my 5 horse mill? And or,,, are there specific questions that I
> should ask this fellow in order to make a judgment.

Practically all the newer VFD's will run on single phase. It does put
more stress on
the rectifier diodes and the filter caps. The power block modules they
use that
have all the power semiconductors in them have a very good current
rating on the
diodes, at least on all the ones I looked up. These things are
generally quite
conservatively rated, anyway. Usually, they are designed for running in
still air
at 50 C or higher. As long as you keep them from getting anywhere near
the high end of the rated temperature, it can probably run up to full
power
on single phase. Of course, if the power block blows, it is very
expensive.
When I'm using a lot of power on mine, I flip on a small cooling fan to
keep the heat sink nice and cool.

Many of the units actually have a published derating for running the
unit
on single phase.

Jon