Re: [CAD_CAM_EDM_DRO] 2 phase power to 3 phase power

G&L wrote:

>Group
> I need to convert 2 phase power to 3 phase. For a 2 HP 4 Pole 200-220
>volt motor for a variable displacement hydraulic pump. What is the best
>way to do this? Rotary phase converter, phase converter, VFD or what?
>
>

My suggestion for this would be a VFD of about 5 Hp rating. Unless this
motor
is normally required to deliver under 1 Hp, and only rarely reaches 1.5 Hp,
a static converter would be unsuitable, as these really allow the motor to
run on single phase power once started. A rotary phase converter would
also work, if built well and properly balanced.

The reason people get away with static converters on machine tools is that
the motors are VERY heavily built, and rarely in the home shop do people
load them to the full nameplate rating. I think the loading of your
hydraulic
pump may be VERY different, such as starting under load, and running under
moderate load all the time.

You most likely don't have 2-phase power, just 120/240 single-phase home
power, as common in the US. Real 2-phase power DID exist in the US,
but hardly ever since WW-II. And, you definitely couldn't run 240 V
appliances
across the two hot wires, as you only get 170 V L-L.

Jon