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Trevor Jones

wrote:
On Feb 11, 5:49 pm, "Jerry" wrote:

wrote in message

...

Can somone post a link to a description of how 3 phaze power works. My
brother is looking at buying a Felder combination woodworking machine
with 3 4kw motors in 3 phaze and while we both worked for an
electrician as kids we never worked with 3 phaze. If he buys it he's
planing on buying a converter as he can't get 3 phaze power at his
place. He worked in a shop with converter while in college but has
never had to set one up.
Thanks
Karl

Hi Karl

Try searching for Three Phase Power in Wikipedia.

Bob Swinney (of this group) can tell you how Rotary Converters work if
you want to make your own 3 phase from a single phase source.

Jerry

Will do. Didn't think of that. I asked my brother if he was going to
make a converter but he's looking at buying an electronic one.
Thanks
Karl

If you have to ask, you probably really don't want to be mucking with
the making of a rotary phase converter anyways.

The vast majority of what you need to know, is that there are three
wires running into the motor, and if you disconnect two of them and hook
those two up in reverse to where they started, it will cause the motor
to run in the opposite direction to the one it was.

A VFD (Variable Frequency Drive) is a pretty wise choice, if you are
not already fairly familiar with, and well stocked with, three phase
motors. Cost is pretty close to or sometimes less than having to buy a
motor and capacitors to use, as well as the requisite switchgear. If you
can read a simple diagram, and follow it up with connecting the wiring
as per, you should have no troubles. If the VFD is used to simply supply
fixed frequency three phase power off the single phase input, you need
not give it a lot of effort in locating it. With three motors to feed
power to, I would suspect this is the way planned.
If you wish to use the "variable" part of the VFD name, consider where
it will be located, and how the inputs are to be fed to the terminals as
required. Tou could, possibly, incorporate the contlols into a pendant
on the end of a cable that would allow the use of the variable speed
feature as desired, when it is appropriate, and use just fixed speed
when it is a better choice.

If you search Ebay for the phrase "VFD" many of the vendors link to
the makers sites where the manuals can be downloaded from. Worth looking
at a few. They will give you an idea of how simply or complicated it can
be made to be.

Cheers
Trevor Jones