Geo-TH,In, Electric Challenge

Back on page 2, Geo-TH,In made a electrical challenge...."I throw out the challenge for anyone showing a a 12 inverter Powering a 2 hp air compressor. Or for that matter any air compressor.".

I'm posting this in a new thread because he may not go back to page two where I replied that I'd accept his challenge.

Anyway, I made a video of hooking my DeWalt 120 volt 1.6 hp 15 gallon air compressor to my 12 volt inverter and powering it up and running it. As I opened my cargo trailer door to show the cloudy skies my thumb slide across the "End" button on my tablet. That is why the video ended so abruptly.

So, George, it looks like your challenge was proven wrong and seems like someone can successfully run a air compressor from a 12 volt inverter.
Here you go George

Looks like George owes you a ride on his Death Machine.

That was quite entertaining.

For the engineer in me, what is wattage on inverter?

Greg as you already well know SURE its possible to run a 120 VAC compressor using adequate battery and Inverter power WELL DUH I cant believe anyone here doesn't already know that AND YOU DO FOR SURE...??..

As an electrical engineer and long ago Century Electric Motor Company engineer plus long time RV Inverter user I agree with you sure its possible WELL DUH lol Of course and I posted and most already know, it may take 3 to 5 or more times current to START a motor then to RUN it. That's why an Inverter needs much more then the run wattage rating, it has to have sufficient surge capacity to get the darn motor started grrrrrrrrrrrrrr

If one needs a small compressor to air up a car or truck tire they might choose

A) A 120 VAC unit plus a 12 VDC to 120 VAC Inverter BUT BIG ENOUGH TO START THE MOTOR plus run it

b) A 12 VDC Compressor NO INVERTER NEEDED. The RV community like ViAir 12 VDC units

C) A Gas powered compressor

There are advantages and disadvantages to allllllllllll of them. One may be more efficient,,,,,,,,,one may be more economical,,,,,,,,,,,one may be more practical BUT ITS A PERSONS CHOICE NOT OURS

SO GO FOR WHICHEVER METHOD YOU CHOOSE AND REST ASSURED, an Inverter will work, a 12 VDC will work, a Gas powered will work

Pleasure chatting with you Greg

God Bless America, keep her safe strong and great, I bet all can agree to that

John T

David G, it' a AIMS PICOGLF30W12V120VR 3000 Watt and 9000 Watt Surge 12VDC Input to 120VAC Output Pure Sine Inverter Charger Backup Power
Poke Here

How big is the inverter? And what is the total capacity of the batteries it's connected to? I have a couple of small inverters, a 160 and 400, they are very handy, but limited to what they can run, I can run a small 4 1/2 grinder off the 400, but barely.

Greg, NICE Inverter I see why it can run that compressor NO PROBLEM WHATSOEVER ...????? Theres a chance my little 2000 Watt 4000 Watt surge might even do it ????????? but there's a ton of variables so it may or may not, Id feel much better with yours lol. Some of the RV gents run rooftop AC units off Inverters no problem, its done all the time given adequate battery and Inverter sizing......

John T

John T, I agree. Use whatever you choose to use. I was not trying to say that this was the way to go. I would have kept quiet and not posted on this at all. Except, George had to go and make a silly challenge about how it can't be done and something about "ending this pie in the sky theory".

That just struck me wrong and is why I replied. I've tried not post on here as much and on some days avoid the site all together. I get tired of a lot of the misinformation and wrong data some people post. I just happened sit down for a quick sandwich and jumped on YT for something to read while I ate. Saw wha George posted and had to accept his challenge. He probably won't reply because it proved him wrong.

Anyway, I like the 12v air compressor you mentioned or the gas powered one others mentioned(depending on what the OP use is).

Have a good one John and take care.

Greg

Russ, 3000W with a 9000 Watt peak.

lol.....ahhhhhhh,,,,,, nope!

Greg1959,

I was unable to view the video. However, what about an unloader? Perhaps a ball valve vented to atmosphere during starting. The only thing starting would be the motor, reciprocating mass, and pulleys.

Thinking out loud, and still probably short.

D>

Dennis Minn, ball valve vent, unloader, reciprocating mass,...you are talking about things that are way over my head! Heck, I don't even know what they are used for or to point one out if I had it.

Hey there Greg, Im enjoying this friendly chat with a fellow RVer. I recall all the fun we had when you were building your system and hope I helped some.

Hey I figure anybody can make a mistake or have a bad day now n then, I'm NOT perfect myself and have them and maybe my fingers get ahead of my old brain lol. I still think everybody here had to know an adequate sized Inverter can indeed power up even a 2HP Compressor, but we all make mistakes now n then.

Indeed there for sure is information as well as mis information on here (Im sure Ive been guilty but I try my best) what else would you expect from such a diverse group of gents who for the most part are trying to help best they can. Of course there are the ones who have an "attitude" Its my way or the highway" and if you dare post an opposing opinion YOU BETTER WATCH OUT LOL. Similar some consider their way as the only way and if you do things different you're wrong and they are right THATS JUST HUMAN NATURE I GUESS. Still the funniest thing is how any Legal or Electrical topic draws out the most responses, what's that all about lol. If its farming or carpentry or plumbing or chemistry or mechanics or painting or landscaping etc etc etc you don't get as much response. Im just glad I have some experience in those (electrical or law) fields and can help at times.

Oh well lets get back to fixing some darn old tractors lol

Take care hope to meet someday down the road

John T

Dennis, good point. The compressors I've owned had unloader valves (relieves any head pressure) so the compressor doesn't have to start under load OUCH. Even if unloaded its all that mass and pulleys and rotors/armatures that are at rest and all of a sudden they have to overcome initial start up friction THATS PART OF WHY IT TAKES MORE CURRENT TO START A MOTR THEN RUN IT but Im sure you know that already. Thats also why all the physics and mechanics and variables and loads makes it harder to calculate start up current versus simple Watts = V x I run current.

PS Id guess any commercial produced compressor has all the necessary unloaders and head pressure relief etc that's required to ease starting

Nice sparky chatting with you

John T

How big is the battery?
What's the LRA and running amps?
How long will battery last?
Good for you proving it can be done .
George

I think most compressors have a check valve at the tank, and the reed valves leak enough that they start unloaded, at least mine do, but most of them I built. Many factory built have an unloader valve built into the pressure switch.

Greg1959,

Aw, give yourself more credit than that. If the compressor did not do anything but spin ( no compression), the only thing that the motor would have to start is itself, a few pulleys, and some mechanicals.

Greg, again, you asking questions keep this site alive and vibrant. I only offer my opinion, and many times incorrectly! Take my words with a rain of salt.

I do not type well, or quickly.

Hope this helps,

D.

George, I have a bank of 8 AGM LifeLine batteries totaling 1200 amp (IIRC).









I would never think of trying to power my air compressor off the inverter/battery/solar, even to pump up a tractor tire. Heck, I've got a 7800W diesel Onan generator hooked up in the RV plus a 3000W gas generator(Might be pretty tough on that bugger) in the cargo trailer.

You challenged to see a inverter power a compressor. I showed you.

We put in 15MW inverter for one of my customers.

WOW! I bet that would power my Popcorn Popper! lol

It was impressive, backed up by batteries and a bank of 2500HP cats, would lay down a cloud of smoke when they started. Plant was fed from 2 substations, one fed the inverter with backup from cats, the other substation fed the non critical power. All controls were 24VDC with one power supply fed from inverter and one from normal power.

So you meet the challenge and proved it can be done. You get the at a boy award.
Congratulations!

You have proven if you throw a lot of money at problem you can solve any problem.

That's a lot of expenses for a small air compressor.

My solution to portable air was to buy a fractional HP air compressor my generator could easily power. Generator and compressor easily fits in truck. I need air to build a privacy fence in a remote location. Cost me $100.

Nice chat.
George

Yup George, Dang! You got me figured out. I went out and bought this stuff and put it together the other day just because you challenged us to prove a 12 volt inverter could power a 120 volt AC air compressor. Yup, that was the only reason I built this setup.

Daggumit George, you outsmarted me again!
Thanks