Re: why not just change the motor?

In my business, I install and program PLC's and inverters (VFD)
everyday. Going to single phase versus using an existing 3 phase
motor and inverter is taking a giant leap backwards.

1. Three phase motors are less expensive
2. Three phase motors are more reliable
3. Inverter technology is proven and used in thousands upon thousands
of industrial applications everyday.
4. Low horsepower inverters are inexpensive.
5. Inverters are not difficult to install.
6. Inverters (when sized and programmed correctly) provide motor
overcurrent protection.
7. Inverters provide reversing capability without having to buy a
reversing contactor.
8. Inverters can provide a means of operating three phase motors from
a single phase supply. Great for outlying areas, or the home shop.
9. Most inverters can communicate by RS232, Modbus, DeviceNET,
ProfiBus, or any number of communications protocols. This can really
cut your installed cost, plus add extra value to your machine.
10. And the biggest point... inverters provide a variable speed output
to a normally constant speed motor. When sized and programmed
correctly, you can have full torque to 1hz or less. Maximum speeds can
be in excess of motor nameplate rpm. In the real world, these
abilities give you much more FLEXIBILITY in machine operation.

Kludge??? NOT.

Bryan Moody
AD&S


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "jlsmith269" <jlsmith269@y...>
wrote:

>big snippage
>
>
> Or, heck, let's get to the heart of the issue, if *I* bought a 2 hp
> boss 8 cnc, 3ph, I would NOT bother with a vfd on it.. i would get the
> wiring and motor from a 2 hp 220 1ph , and bolt it on... and yeah, I
> would spend DOUBLE or more for that simple solution, rather than
> kludge it, knowing I am introducing unknowns into a pc-cnc/enc setup.
>
>
> thoughts?
> jeffe
> > >