Using weaker phase converter to slow down compressor?

[BenKlesc]

Yes I really am considering a rotary phase converter.

I will ask a professional in my area who deals with this. Can get my hands on a used one for a good price.

My blaster with a 3/4" hose and 3/16" nozzle, more CFM the better. 55-65CFM, around what I would like.

This compressor would be about just enough. Also again, I have about 100 amps not being used on my 200 amp box.

 

[Strouty]

Just so you know, the second your tip starts to wear, it will need more CFM since the orifice will be larger.

I bought a duplex compressor to run my big cabinet, but have not gotten to the point that I can use it yet. I don't make any money with my stuff, so things happen really slowly. If I run two 10 hP motors at 940 RPMs on the pump, I can get about 72 CFM.

 

[BenKlesc]

I should post pics some time. I built the blaster on wheels myself from my own design. That's another story.

I have no idea if it works yet but should. Kaboom I hope not. I'm using steel carbide tips, stainless steel pipes.

 

[Strouty]

Whatever you do, don't tell anyone that you made the pressure vessel.

So what size PVC are you using for your air lines?

 

[BenKlesc]

Whatever you do, don't tell anyone that you made the pressure vessel.

So what size PVC are you using for your air lines?

All 3/4". Nicknamed, "da bomb".

 

[mike93lx]

This is the same garbage, page after page. You guys that are trying to help are better men than i. You aren't getting through to him. Let him waste his money and enjoy the show

 

[laser3kw]

longest trolling thread - ever

 

[OccupantRJ]

1930?, that you?

 

[BenKlesc]

Okay I just got the confirmation numbers from Quincy. It would be 50 amps running on single phase power 230V. 36 amps running on 3 phase power 230V.

Not including phase converter...

 

[wyliesdiesels]

Yes I really am considering a rotary phase converter.

I will ask a professional in my area who deals with this. Can get my hands on a used one for a good price.

My blaster with a 3/4" hose and 3/16" nozzle, more CFM the better. 55-65CFM, around what I would like.

This compressor would be about just enough. Also again, I have about 100 amps not being used on my 200 amp box.

how do you know this? Have you done a load calc?

 

[Strouty]

Okay I just got the confirmation numbers from Quincy. It would be 50 amps running on single phase power 230V. 36 amps running on 3 phase power 230V.

Not including phase converter...

I don't know where that number came from, my single phase 10HP draws close to 50 amps. A 15 HP will draw even more.

 

[Strouty]

So I was wrong, it is 40 amps for my 10 HP.

 

[BenKlesc]

I met with someone today who owns a 15HP Quincy running on single phase power. He pointed out that my model also has unloaders, to help reduce start inrush amps.

My electrician seems to think it would be okay on my 200 amp box. Further testing is going to be conducted. I will now be contacting the company who makes those phase converters, for power consumption data.

 

[Strouty]

If you run this on a phase converter, you will need a 30 HP unit at a minimum and that will definitely pull more than 50 amps.

I think the inrush on my 10 HP was something like 230 amps, so you will tax your system substantially. My shop is stand alone, I do not think I would want this type of draw connected to my house panel.

 

[mike93lx]

I think the inrush on my 10 HP was something like 230 amps, so you will tax your system substantially. My shop is stand alone, I do not think I would want this type of draw connected to my house panel.

Nor does the POCO

 

[Bert_]

I agree that 50A load is pretty optimistic, here's the tags off a couple single phase 15's.


[url=https://flic.kr/p/2camdtq]

I can't say I am as concerned about running this on a 200A service as many others. As long as you have 75A of capacity left it should be fine. Might want to check on the transformer size but be careful since the utility might not like a motor this size.

 

[BenKlesc]

Is it also true that 3 phase motors last longer than single phase?

Two options:

Replace with a single phase 15HP 230V motor. (Better option)

Run phase converter off an industrial gas generator. (Bad option)

 

[ez-duzit]

Replace 3 phase motor with a gas motor.

 

[Strouty]

If you go with a single phase 15 HP motor, you may be able to get a VFD to use for a soft start, since the compressor is normally unloaded the motor would be able to start at less than full power.

 

[alfredeneuman]

It would be 50 amps running on single phase power 230V. 36 amps running on 3 phase power 230V.

Math conversion says that if it is 36A on 3 phase, it would be 62.3 on single phase.
To convert from 3Ø to single phase you multiply by the square root of 3 (1.732)

 

[BenKlesc]

Of course there is one other option, and that is installing a dedicated breaker for the garage if I want to make this a permanent solution. Even single stage motors take a lot of amperage. That is something to consider down the road if I want to get serious about this setup.

 

[alfredeneuman]

Even single stage motors take a lot of amperage.

Huh???

 

[BenKlesc]

Huh???

Excuse me typo, single phase.

15HP single phase motor would still be close to 60 amps.

If I run a dedicated 200 amp breaker box for just my garage, I would be able to use the phase converter and keep the 3 phase motor. Something to look into, for side business.

 

[BenKlesc]

I had no idea about these, just began researching.

Turns out there are 3 phase portable generators, such as this one below.

https://www.absolutegenerators.com/...25eh-3-4-10-kw-480-volt-dedicated-22-hp-honda

Also another possibility, very expensive though.

If I can find a gas motor that would fit on the compressor, that would work.

 

[sberry]

You are doing your best to find the long way around.

 

[brewchief]

I had no idea about these, just began researching.

Turns out there are 3 phase portable generators, such as this one below.

https://www.absolutegenerators.com/...25eh-3-4-10-kw-480-volt-dedicated-22-hp-honda

Also another possibility, very expensive though.

If I can find a gas motor that would fit on the compressor, that would work.

You would need a much larger generator to start a 15 hp motor, probably along the lines of a 30-35 kw.

The local sunbelt rental will rent a 90cfm diesel tow behind compressor for around a 100$ a day or 300ish$ a week, I would again suggest that you go rent one and try it out.

Sent from my SM-G965U using Tapatalk

 

[Aceman]

You really need to contact your power co.

Over here, they want to be notified if you have anything larger than a 5HP so they can verify their infrastructure can handle it.

If you fire that compressor off without notifying them, and you start blinking all your neighbors lights, be ready for them to pay you a visit.

 

[dkmc]

Anxiously awaiting a report on the new compressor performance numbers....

 

[LS6 Tommy]

My .02, blasting in a cabinet in a home garage is fine, blasting outside would be out of the question in a normal neighborhood.

Dustless blasting is awesome.

Tommy

 

[BenKlesc]

You would need a much larger generator to start a 15 hp motor, probably along the lines of a 30-35 kw.

The local sunbelt rental will rent a 90cfm diesel tow behind compressor for around a 100$ a day or 300ish$ a week, I would again suggest that you go rent one and try it out.

Sent from my SM-G965U using Tapatalk

Why is that, starting watts much higher too?

My motor is rated @8KW 3 phase power. 18 amps @460V.

 

[larry_g]

Why is that, starting watts much higher?

.

Search out inrush current and CEMF or counter electromotive force. Short answer is that a non-rotating motor is basically a dead short to the incoming power.

lg
no neat sig line

 

[wyliesdiesels]

Why is that, starting watts much higher?

My motor is rated @8KW 3 phase power. 18 amps @460V.

Yes in-rush current is 4x-8x of the motor FLA.

Any inductive load will have in-rush current when starting.

 

[BenKlesc]

Well I just looked into the option of replacing the electric motor with a gas engine.

I am checking into whether my pump has unloaders, but if you do switch to a gas engine you must have unloaders so you can start the engine without the load of the compressor.

Other than that... If I want to replace a 55-60CFM 15HP with a gas equivalent, I would need a 30HP gas engine that could run @1700RPM or adjust pulley ratio.

More of a pipe dream than anything else that would cost thousands too. So I don't have access to 3 phase power in my area, and don't want to pay the electric bill of running 10,000 watts @ 110 amps. So I'm going to do it the right way, and will be posting back updates on this thread next year.

I will be building an elaborate scheme. I plan on working around the power company to supply 3 phase power to my home all perfectly legal. The power source will fit inside of a small closet, and will power the phase converter and compressor motor with room to spare. Full sails ahead. Place your bets.

 

[mike93lx]

The suspense is killing me

 

[strutaeng]

Well I just looked into the option of replacing the electric motor with a gas engine.

I am checking into whether my pump has unloaders, but if you do switch to a gas engine you must have unloaders so you can start the engine without the load of the compressor.

Other than that... If I want to replace a 55-60CFM 15HP with a gas equivalent, I would need a 30HP gas engine that could run @1700RPM or adjust pulley ratio.

Basically more of a pipe dream than anything else that would cost thousands too. So I don't have access to 3 phase power in my area, and don't want to pay the electric bill of running 10,000 watts @ 110 amps. So I'm going to do it the right way, and will be posting back updates on this thread next year.

I will be building an elaborate scheme. I plan on working around the power company to supply 3 phase power to my home all perfectly legal. The power source will fit inside of a small closet, and will power the phase converter and compressor motor with room to spare. Full sails ahead. Place your bets.

Next year?

 

[BenKlesc]

I have not confirmed this.

Is watts increased when starting a motor, or just amps?

I know soft starting is about reducing KVA.

 

[ez-duzit]

...Is watts increased when starting a motor, or just amps?....

Watts = volts X amps. So, if amps increase, so do watts.

 

[Strouty]

I will be building an elaborate scheme. I plan on working around the power company to supply 3 phase power to my home all perfectly legal. The power source will fit inside of a small closet, and will power the phase converter and compressor motor with room to spare. Full sails ahead. Place your bets.

I think you need to stop trolling, in fact if you keep this **** up I am going to report you for effing with us.

 

[BenKlesc]

I think you need to stop trolling, in fact if you keep this **** up I am going to report you for effing with us.

It's 100% serious. It's a bodyshop.

Will be posting photos of the build at the end of the year.

 

[86turbodsl]

I went down this rabbit hole for a long long time. 10HP compressor with 3 phase motor and a 50HP rotary phase converter. It's what i named my shop thread in fact.

After a long time, it became much clearer that on a single phase supply, it makes a lot more sense to move to a 5HP compressor and just double them as needed and downsize the RPC a bunch. I now have a 20HP rpc. With a pony start motor. It makes a lot more sense. You'll probably come to that conclusion eventually.