POLAND_SPUD wrote:I suppose they can... I normally use fridge compressors at higher pressures

Because I'm pretty certain the Danfoss SC18CLX.2 qualifies as a fridge (eh, make that a freezer) compressor. And that compressor will be my second stage.

Shingoshi

yes, compressors like these are designed to work in closed loop... we use them for pressuring atmospheric air and there are some extra problems with it that daberno mentioned normally refrigerant flows through the tubing in a closed loop... in refrigeration systems there is often a filter right aft...

I use this for pressurizing with air only. The lubricants in the pump slowly get blown out. I should probably put a few drops of oil in it to keep running smoothly, but I haven't felt the need to yet. I don't see why all refrigeration compressors couldn't be used for pumping air, its just another g...

I need clarification here. Was this Rechi compressor intended to be used for pressurizing air only? If so, could I do the same thing in a closed-loop? I think the advantage of having a closed-loop, would be the elimination of condensation as you mentioned. Besides, I could add other gases to the mix...

Technician1002, I've decided to pm you instead of continuing this here. My topic doesn't belong here. Shingoshi EDIT: Is there anywhere in this forum where a topic such as mine can be discussed? I'm sure there would be others to find it, just as I found this one (using Google). This way, I wouldn't ...

Ok. So I need more clarification here. 1.) So I have a high-temperature A/C compressor. How does that affect my selection of available refrigerants? Like CO2 or Propane? Which refrigerant will give me the lowest temperatures possible while being usable in this compressor's oil? 2.) What I was going ...

May I please have your permission to post this in the thread for the project I'm building. I think every chance more people have to get good information, is good for everyone. So I really hope you approve.

Shingoshi

Man! I'm nowhere near the tech you are! I'm going to copy this to a file that I can refer as often as I need to. I really appreciate this response. I think maybe I ought to be building spudguns instead of computers.

Really, Thanks a lot!
Shingoshi

The inductance of the motor is matched to the capacitance of the starting cap to provide a phase shift. This is used to provide a rotational field to start the motor turning. Too big of a cap is bad and will result in too much current and an incorrect phase shift to properly start the motor. It may...

Maybe I didn't understand you. I thought the capacitor was only responsible for starting the motor. If that's correct, then I think my statement is also correct. Shingoshi first of all tech is a proffesinal electrition so i think he knows what hes talking about. and second what advantage would you ...

Maybe I didn't understand you. I thought the capacitor was only responsible for starting the motor. If that's correct, then I think my statement is also correct.

Shingoshi

That's fine, the only disadvantage to using an over-rated cap is the size, really. Usually AC motors have big metal oval-shaped caps (they're unpolarized electrolytics, I believe). You'd probably want one of those. Being that I have four compressors, is it possible to use a single larger rated capa...

the highest is 200psi but it can go much more than that. i checked the compressor, the capacitor and could not find any word saying 15uf or 25uf. how would i know if it's a 15uf or a 25uf? Since I'm not limited by the factors (chamber pressures) any of you have to work with, just how high of a pres...

That's fine, the only disadvantage to using an over-rated cap is the size, really. Usually AC motors have big metal oval-shaped caps (they're unpolarized electrolytics, I believe). You'd probably want one of those. Being that I have four compressors, is it possible to use a single larger rated capa...

Can I just use any capacitor for this, or does it need to be a special run capacitor? I've been browsing some HVAC parts sites but can't find any 270 volt capcitors, only 370 and 440. I have just purchased FOUR of these for a special project I'm engaged in. Reading the specs given by Ralphd, I now ...