Connecting two compressors for more volume?

PILOON · Nov 26, 2005

Auxillary tank is a good way to go, as others have mentioned.

An affordable tank is a propane tank! The valve is threaded into a 3/4" fitting so it is simple to use a bushing to adapt down to your airline.
I drilled and welded a drain valve on mine.
I use a 60 pound cylinder.

cmuncy · Nov 26, 2005

Talking about TSC, I came upon the deal of the century a few months back.

I was at the local TSC getting some fencing supplies and I has drooling over this HUGE Ingersol Rand out front.

80 gallon
19 CFM @ 90 PSI
175 PSI Peak
15 HP ( might be a few more or less)

Looked like it had been used and returned. I went inside and asked the manager what they wanted for it.

...are you sitting down??

...seatbelt on??

 $400.00!!!! 

The manager said the compressor was throwing belts. After I called the CFO and got permission to get the compressor, I met her and the kids at the local mexican restaurant. She sees me and exclaims " WTH is that in the back of your truck??"

She had no concept of how big it was.

Anyway, the problem was the compressor motor was not inline with the pump pulley. Off almost an inch.

THis was truely my deal ofthe year.

For those interested, the TSC in Conroe usually have on ofth elarger I-R compressors out front for sale at less than 1/2 off their usual retail.

The good deals are still out there. /forums/images/graemlins/grin.gif

drmiller100 · Dec 10, 2005

u REALLY want the two compressors to be on different electric circuits.
playing games to keep the breaker from trippping is not a good deal, as you could potentially overload the wiring, causing the wires to get hot.

Soundguy · Dec 11, 2005

( playing games to keep the breaker from trippping is not a good deal )

Who mentioned this.. i didn't see it in Bob's posts.. about fiddiling with breakers to keep them from popping at correct load.. etc???

Soundguy

BobReeves · Dec 11, 2005

Ya, have 100 amp service to my shop, power and having enough breakers is not an issue. Trying to come up with the bucks to buy another compressor is /forums/images/graemlins/smile.gif

3RRL · Dec 11, 2005

Bob,
No problem in doing this. I've done it in my plant with larger compressors.
However, be sure to use use different breakers for each AND check to see if they shut of at the same time. It is a good idea to set the regulators to the smaller compressor rating so it does not over work itself, or if anything, set the larger one at slightly higher than the smaller one.

FarmGeek · Dec 15, 2005

I used to run one compressor and two tanks for increased volume but I like the idea of two compressors.

One word of caution, electrically speaking, is if the units are close enough for you to touch them both at the same time. If this is the case, make certain each breaker is on the same incoming -leg- or phase of the main panel. Otherwise there can be a 220v potential between them and that stings. /forums/images/graemlins/tongue.gif
Also, this will eliminate the possibility of any metal fittings becoming a source for ground potential bleed-off in case either phase is unbalanced (sorry to all electricians for and incorrect terms used).

I know this is not common but I've still got a mark! /forums/images/graemlins/shocked.gif

uhmgawa · Dec 19, 2005

( Just came back from a little shoping spree.. Best Attwoods had was a 5 HP 20 gal for around three hundred. Anything over 5 was big bucks. Looked at the 7+ HP uprights at Harbor Freight and they start at over a grand even for the store brand.)

Experience has shown the HP ratings of current day
air compressors to have been chosen either by Alice
in Wonderland or the marketing department -- whoever
has the lesser grasp on reality.

As a rule of thumb the actual HP ratings are about
50-60% of that which is otherwise claimed on the
unit. This applies mostly to the consumer grade
equipment in the $450 and under ballpark.

If there is any doubt just take a look at the amperage
draw on the motor rating plate. At 240V assuming
85% efficiency an induction motor is going to draw
approx. 3.7A per HP (746W).

Louisiana_John · Dec 20, 2005

I did this at a buddys house. He has a shop at his house were he does paint and body work. He had a 5 hp 60 gal and I had a Sears 6hp 6gal. They are the ones you see for $ 400 to $500 nat a real 5hp and 6 hp. We tried setting the on press at the same would not work one would always run all the time when using a DA. I ended up running them of the same switch they have worked fine for years.
I have a 3 phase 10 hp IR in my shop now it has 35 cfm rating. It is still work hard when blasting. I picked up a 2nd used this one is a Granger 10hp. When I get time I will build a rack and stack them and wire into the same switch with each compressor have its own realy. That way when I need the 2nd one I will have it.
John

Soundguy · Dec 23, 2005

( Experience has shown the HP ratings of current day
air compressors to have been chosen either by Alice
in Wonderland or the marketing department -- whoever
has the lesser grasp on reality.
)

Deceptive marketing.. sure.. no grasp of reality?.. I think you are overstating it a bit. Hit an electronics manual, and look up the difference between RMS, and PEAK, looking at current.. now.. calculating motor hp, think about those ratings again, and you will see where they get them.

Definately deceptive.. though.. everybody is doing th peak rating thing.. car audio amps.. speaker wattage.. etc.

Heck.. lawnmower engines.. look at those. those puppies are rated, generally with no load add ons like pumps / fans.. and running at different carb settings, at an rpm not attainable or used by the onsumer, and max hp rating is marked just before the engine detonates... I'd guess you could safely drop them by a 3rd and have something close to real hp at the blade for cutting..

Soundguy