Who has an air compressor with a phase converter.

[Tractor Seabee]

There is a lot of info on motor starting methods such as this one:



Ron

 

[ultrarunner]

You could try to reduce the inrush current. Most compressors have an unloader. The problem is that the pipe between the compressor and check value is short and the compressor quickly gets loaded while it's still ramping back up to speed. You could take it a step further by having the compressor just vent to atmosphere for a few extra seconds with an electric valve before closing so the motor starting up and the load of compressing air are separated.

I have a very old Devilbiss Commercial Compressor that has a built in unloader... the motor never starts under load and this 1950's compressor is remarkably quiet.

 

[claya]

What have you done to resolve getting power to this compressor? 3Phase, or switch over the motor to single phase?

I have a 40Hp RPC, running a Machining center, and am looking at this exact same compressor. Would also like to cycle the converter ONLY when the compressor needs air.

clay

As the title says, would here is running a 3 phase air compressor with a phase converter.

I acquired a joy twistair ta010. Not sure the cfm but it's pretty good. It will charge it's 80 gallon horizontal tank from 0 paid to 120 paid in about one minute flat.

But ran low on oil and locked up. So I am gonna look into a rebuild as it is a nice compressor.

It has a 10 hp motor.

I am no stranger to phase converters and vfd's.

I have a 10hp rotary that is running a mill and lathe currently. And another 15 hp rotary not used now. And a 5 hp vfd I use for the log splitter.

If I need to use the mill or lathe, it's no problem to just push the button and start the rotary.

However....the compressor I just want to be like my current one. Plugged in ready to do it's own thing whenever it needs to charge. Don't want to have to worry about starting a phase converter Everytime I want a little air, or Everytime it needs to kick on. But also don't want to leave the rotary running 24/7 either.

So those that are running a 3phase compressor off a converter.....what setup are you using?

 

[LD1]

I went with a single phase 10hp / 240v motor.

Sorry i never updated thread

 

[Industrial Toys]

Best thing! I bought a BIG Lincoln Welder at an Auction by accident that was only three phase. I built a nice 10HP 600 Volt phase converter. Then got a drill/milling machine. What a pain to stop and start a phase converter. I sold everything 600 volt and bought a Lincoln 220 volt MIG. I don't even know how you would stop and start a rotocon for a compressor.

 

[LD1]

Starting and stopping the phase converter is no big deal for things like the mill and lathe. Just two buttons to push to start the lathe I stead of one.

But the air compressor was a different animal. It starts and stops on its own whenever it needs to. Sure, one can wire up the phase converter to the pressure on off switches....and a start up timer to give the converter a few seconds to get up to speed before starting the compressor.

But at the end of the day, it was just easier to get a single phase motor. And if I happened to be turning something heavy on the lathe.....and the 10hp compressor decided to kick on....that probably wouldn't be good unless I went even bigger on my phase converter

 

[claya]

What motor and pulley setup did you go with? And can you measure cfm? I need a bare MINIMUM of 28cfm, and probably 40cfm is better in my situation. But, Pretty sure running my 20hp spindle on the MILL (VMC) when the compressor kicks on will be bad, if I keep the compressor 3ph, as suggested. Sent a couple PM's. Did you get them?

 

[Industrial Toys]

My 10 HP Rotocon draws insane amounts of power on startup. Not something you want to be starting and stopping every time you want to drill a hole. It's possibly not even allowed by the utility to suck such inrush currents!

 

[LD1]

What motor and pulley setup did you go with? And can you measure cfm? I need a bare MINIMUM of 28cfm, and probably 40cfm is better in my situation. But, Pretty sure running my 20hp spindle on the MILL (VMC) when the compressor kicks on will be bad, if I keep the compressor 3ph, as suggested. Sent a couple PM's. Did you get them?

10hp single phase motor. Pulleys are the ones that came with it. Not sure exactly what you are asking for.

No way to measure actual cfm.....other than it charges the 80 gallon tank to 110psi in 3m25s.

Doubt that I am actually getting 40 cfm.

The head was locked up when I got it. So lots of trash went through the rotors. But with these types of compressors they will still make air, just less of it.

My old 9cfm piston type takes 4 minutes to get a 30 gallon tank to 110psi. So I am definitely getting alot more air.

I haven't changed the separator filter yet either, so I'd probably gain a little there too

 

[claya]

You had mentioned changing the pulley ratio to maintain the cfm/pump rpm etc.. From what psi to 110? Will help some in estimating the cfm. Or is the tank empty to 110psi in 3min25s?

I need at LEAST 30cfm, bare minimum. Have not bought the Twistair, yet. Just following your lead, and doing the maths. I expect to need to rebuild the pump bits on the one I am looking at. Expect it has LOTS of hours on it. I have the chance to buy a much newer, yet more expensive to run/maintain 15hp Ingersol.

Which motor #? You listed several choices. I need to consider the $$$ and amp load of running yet another 7.5-10hp on my 200A panel. Plus, I only have 25kva on the pole feeding two houses, and 3 shops. So expect to get some heartburn from the utility company, once I start pulling some serious amps.