There really aren't any other choices. On a container, sounds like it is temporary. The generator may be the best option, on less fuel is a problem.If its temporary I would go with a generator.
Permanent will need a phase converter and a transformer.
Is that free and clear capacity or does it include other loads not mentioned?..the only source available supply is 220volt single phase at 150 amps capacity...
Not to mention starting current...........Is that free and clear capacity or does it include other loads not mentioned?
If you are looking at permanent, you need to know. That 440V 3? 25A load converts to 220V 1? 87A load with no padding for conversion efficiency. If a single motor compressor load, it gets factored 125%, so you're looking at 108A calculated load minimum.
Not to mention starting current...........
Hi Al.the capacity is free and clear no other loads
I need to supply a refridgerated container with 440 volt 3 phase at 25 amps, the only source available supply is 220volt single phase at 150 amps capacity.Any suggestions how to get this done?
I think using capacitors for three phase motor on single phase possible and has no motor derating problem. But cost may be the deterrent.There really aren't any other choices. On a container, sounds like it is temporary. The generator may be the best option, on less fuel is a problem. If it is permanent, then you have various choices of phase converter options. With a hermetic compressor motor, those choices are further limited to either a Rotary Phase Converter (RPC), or an electronic phase converter, like a VFD or a "Phase Perfect" unit. Stay away from the Static Phase Converters because they basically just "trick" the motor into starting with single phase, but de-rate the motor capacity when running. That's OK for some loads, but will smoke your compressor on a refrigeration compressor.
There is no combination of fixed value capacitors that can do what you suggest over both motor starting and various fractions of full load.I think using capacitors for three phase motor on single phase possible and has no motor derating problem. But cost may be the deterrent.
For sure. To do that though you would have to be super strong, super smart, super fast, and have a capacitor that can't be found. Who among those born on planet earth can do all of this? Not many.Consider a three phase supply with one phase lost. If a suitable size capacitor is connected between the lost phase line and a healthy phase, rated current of the motor may flow in each line with a phase shift from the capacitor, thereby making the motor works as a single phase motor and it may develop rated output as rated current flows in each of its winding.
Those are not as hard to find.Of course to suit this to the OP, a transformer is required to step up 220V to 440V.
Actiondave:
Here are many circuits of three phase motor run as single phase motor for your scrutiny.
https://www.google.co.in/search?q=t...ning-3-phase-motors-with-1-phase.html;297;178
Yes. You are correct. This refrigeration compressor is not going to start with 220V single phase. It is rated for 440V (See my post#11 to clear your confusion.)Just stop, really just stop.
This refrigeration compressor is not going to start with single phase.
:?What you described in post 11 is exactly how a static converter works, along with a second starting capacitor and control method to switch the start capacitor in/out of the circuit.The only reason static convertor motor oversized is one winding unused.That is not the case for suggestion in post#11.
Let the voltage be 440V as in OP case. What size capacitor for 25A?:?What you described in post 11 is exactly how a static converter works, along with a second starting capacitor and control method to switch the start capacitor in/out of the circuit.I have yet to see one that allows for balanced output current across the three leads to the motor.Most recent one I dealt with had a motor rated about 25 amps, one line would draw up to 40 amps when at highest load level, and the other two lines would vary depending on how much capacitor was connected but always would sum up to the other line because ultimately what ever comes in one line may split two ways but all has to leave the other line on a single phase supply. I could connect capacitors to get decent current balance but that was when motor was lightly loaded. Static converter only works well with constant load applications, and typically requires derating the motor AFAIK.