3 phase help please

[robdot]

Hi All,
I have a small manufacturing site that is only supplied with single phase power but I require 3 phase for my machine shop equipment. It is pretty much impossible for me to get 3 phase to the shop (not just a cost factor). I am considering using a diesel generator. I have 4 machines that are 575V 2-4amps and one that is 220V 3amps (all 3 phase). Most of the generators I have seen only produce up to 480V. Can anyone give me suggestions ( on generator size, motor/generator wiring)? I would appreciate some background info/suggestions before I spend my money on generators/electrians...


Thanks,
Rob

 

[rbulsara]

There are Phase Converters available. Both rotary and electronic, I think. Search the net.

For simplicity stay with rotary. I personnaly never used one but they apparently they are common in remote rural areas. I beleive they are nothing more than a single phase motor driving a 3 phase generator (alternator).

 

[GGOSS]

Hello robdot,

Try

http://www.polyphaz.com

Manufacturers of static and rotary converter products. Although they are based in Western Australia their logo is "single to three phase converters for the world market.

Highly respected throughout Australia, they have been doing this stuff for many, many years.

Regards,
GGOSS

 

[peebee]

VFD's might do the trick for you.

Swapping out the motors with 1-phase motors might be another idea.

M-G sets and static phase converters are potential ideas as already mentioned.

The generator is probably the most expensive solution.

 

[busbar]

There are many phase-converter producers that have websites with a degree of online applications information. The 60hz non-generator solution is probably the best for saving engine maintenance. You may want to contact prospective sellers and give them your application in detail. One problem may be getting a stiff enough 1ø source so that starting voltage-drop is not an issue. It may be that one or more producers could guarantee successful operation of their recommended system. Some seem fairly sophisticated—such as offering “CNC-grade” products.

 

[jOmega]

Toshiba and other VFD mfgrs make 1-Phase input - 3-Phase output VFDs ...

Those mfgrs that don't make a dedicated 1-Phase input VFD, sometimes offer their 3-Phase input products but derate so as not to overburden the dc bus structure (including bridge rectifier). An example would be to use a 10 or 15 hp rated 3-phase input VFD for a 5 HP 3-phase motor application. (Mfgr MUST be consulted for derating specifics).

Preference would be for a VFD with a dc link reactor as with a single phase supply, the dc bus ripple current will take a leap ... and short capacitor life and degradation of output waveform could result. Reactor acts to improve filtering of ripple.

 

[VicP]

What is your single phase voltage? Assuming you have 230 volts single phase, a phase converter would convert 230 volts single phase to 230 volts 3 phase. This would run your 230 volt motor. A 230/575 volt, 3 phase transformer would give you the 575 volt, 3 phase you need.

Check this website for info on phase converters.

http://www.phaseconverter.com/

 

[Warpspeed]

Have to agree with peebee, replace the three phase motors with single phase motors. This will almost certainly be the cheapest and most reliable solution to your problem.