Three Phase Converters

[TopherTony]

I have a compressor that runs off of three phase 220v power.
I have a static inverter at my house but as anyone who has ever used these will know, they only put out 1/2-2/3 of the rated power of the motor they are powering due to the nature in which they are made.

Has anyone used one of these to power their compressors? What type of performance hit have they experienced. My uncle has a rotary phase convertor from Phase o matic that I can buy off of him for cheaper but they are still expensive, large and not easily moved around. They are rated for use up to 90-100 percent of the power so I can use that when I am back home.

I want to install the static inverter inside the case containing the unit for easy portability because they simple aren't that large but want to see what the community thinks about using one.

http://i24.ebayimg.com/01/i/01/47/f8/26_1.JPG

btw...does that really say 40.5 Amps??

[star882]

That's LRA, which is basically starting current.
You can use an inverter, but it would be complex.

[PhilippF]

You can wire 3-phase units in two different ways:

1. In a star, which means all three coils are connected to neutral in the center and one coil to each phase.

2. In a triangle, which means every coil is connected to two phases.

The voltage in the two wirings differs by a factor of (root(3))=1.73

In your case:

You can connect your comp in STAR-configuration in Germany which means every coil gets 230V (phase to neutral voltage).

In the USA you can connect your comp in TRIANGLE which means every coil gets 115V*1,73=199V

Both is in the specified range.

A problem occurs if you dont have a 3-phase outlet but only 1 phase (you would need a complex converter), but I think the powerage of this comp exceeds the max power that can be delivered by a standard wall outlet so this is no option at all.

If you have further questions, please tell me.

Regards,

Philipp

[PhilippF]

I found some pictures. 400V is for Europe (230V system), in the states it would be 200V

[DetroitAC]

I think LRA is Locked Rotor Amperage, the current draw if the compressor seizes

[PhilippF]

I think LRA is Locked Rotor Amperage, the current draw if the compressor seizes

Sounds right...

[TopherTony]

its wired in delta config currently....what called 'star'
i have contacted the power converter company and they are going to send me some info

[PhilippF]

Nope, Delta must be triangle, otherwise you wouldnt get 200V in the States....

[Duh]

TopherTony:
too much hassle IMO...you should send it to my gome ( have 220) :cool:

[[486]]

you can build one from a old 3- phase motor, there are plenty of sites to help you, me and my dad made a 10HP one for his bridgeport mill, but if you don't want to make one, get the rotary, it will provide stable current if it is set up right, and the motors that run off of it will further stabilize the current