Quncy air compressor, 3 PH: at what point....?

[FTG-05]

I have a line on a Quincy air compressor, but it's probably a 3 ph machine.

At what price point does it make sense to buy the 3 ph models knowing that I'll have to replace the 3 ph motor (and controller?) with a 1 ph motor?

The model is a QT-7.5 and I would probably plan to replace the motor with a 5 hp version.

Thanks for any insight.

 

[chrispyny]

Well, i did EXACTLY this to EXACTLY the same compressor so i should probably start.
Considering its a quincy, you don't want a crappy 5hp motor. I purchased a baldor 5hp off ebay nrand new shipped was like almost $650
I called quincy, told them my plans and they sized the new pulley on the motor for me (smaller to ease the load on the now less 2.5hp motor. i ordered the pulley with the part number quincy gave me from a quincy dealer 15 min from my house for about $30. I bought a new belt at tractor supply for about $20. Bought a new mag starter off ebay for about $150.
Not including the compressor i won at auction. Just to get the compressor running cost me about $850 after the dust settled.

I got the deal of several lifetimes on a huge lot of quincy compressors and parts last spring. Once i sold off all the stuff, i actually kept my qt7.5 and have made my money back from the auction, and the money i spent to get it up and running.
I still have two $2,000 mag starters, and a like new 3 phase baldor motor with pulley and sheave i cant seem to sell for pennies on the original costs of these things.
I had a thread i started when i won the auction. Look my name up and search for threads i started. I STOLE that auction.
Lemme know if you have any other questions or private message me if i can help. I got tons of pics somewhere.

I should add that your minimum motor size is 5hp. 7.5 in single phase is very expensive and the mag starter/brakers/wiring will cost you way more. Stay at 5hp.
Also, unless fudged by a previous owner, the machine is most definately standard with a 7.5 hp 3 phase baldor motor.
If you asked me how much you should pay for the compressor, considering you can order the same thing from quincy NEW with 5 hp motor for like $2,500. I'd tell you not to spend over $800-1000 unless you know the compressor is MINT.
I took the head off mine to check the cylinders prior to spending the $850 to get it running. Mine were perfect. Oh, the pressed graphite gasket set and one can of quincy new blue were VERY expensive. Head gasket kit was like $120, and one can of paint was $32 plus shipping off some guy online.
Good luck.

 

[fatfillup]

Depends on how much current you can get to the compressor. Most motors over 7.5 hp are going to be 3 phase. I have seen 10 hp 1 phase but they are pricey and draw a lot of current.

 

[FTG-05]

Good stuff Chris, thanks! Sounds like it's not gonna be worth it. This assumes, of course, that it is a 3phase machine. I don't know yet since the guy selling it is on vacation and I'm not sure he's watching his work VMs.

$1000 is the asking price and $2500 is about what I figured for a brand new one from Quincy. That should not be interpreted as saying I want to spend $2500 - I'd like to spend a whole lot less!

Depends on how much current you can get to the compressor. Most motors over 7.5 hp are going to be 3 phase. I have seen 10 hp 1 phase but they are pricey and draw a lot of current.

Power shouldn't be a problem. I have a 200 amp service in my shop that comes direct off the transformer and have over half my slots still open. This assumes I can find the properly sized CBs for this box. I forget the designation, but they are standard CBs that I can get from HD. Just don't know if that type CBs go that high (+75 amps).

 

[Strouty]

If it is 3ph with a 7.5, you may be able to use the same starter for a 5 hp 1ph, just use two legs instead of three.

I am in process of doing what you are doing, except mine is a tad bit bigger.

 

[WhoWhatNow]

I bought a complete 325 with a good tank and 3ph motor for $300. By the time I was done I figure I had about $1000 in it. I bought a new 5hp 1ph Baldor motor and a good quantiy motor starter because I wanted this to be the last compressor I every buy. I probably have another $200 in the cooler that is still to be mounted. The little things like fittings and a new pressure relieve valve do add up.

 

[chrispyny]

Good stuff Chris, thanks! Sounds like it's not gonna be worth it. This assumes, of course, that it is a 3phase machine. I don't know yet since the guy selling it is on vacation and I'm not sure he's watching his work VMs.

$1000 is the asking price and $2500 is about what I figured for a brand new one from Quincy. That should not be interpreted as saying I want to spend $2500 - I'd like to spend a whole lot less!

I hear you loud and clear. You are welcome my pleasure.
I'd like to add that if the compressor has already been changed over to single phase, done well, and with at least a decent quality 5hp single ph motor, with appropriately downsized motor pulley and mag starter, then an asking price of $1,000 is very fair. But i'm cheap so i would definately haggle as best i could. Assuming all that work is done, $800 is a sweet deal and the number i'd look for if it sounds good running.
Here's mine, basically free. Hehe. Sorry had to toss that in there

 

[FTG-05]

Nominated for the "You ****" of the year award!

thanks,

[beer]

ETA: or however you make that beer icon show up....

 

[tarbellb]

Now that is a good looking compressor Chris!

Personally, in the Denver area when I was looking around I could find monster (5-25hp) 3ph compressors all the time for <$1000, and sometimes <$500.

Personally I would only do it if A) its in good to great condition, B)<$500.

Good luck.

 

[FTG-05]

I bought a complete 325 with a good tank and 3ph motor for $300. By the time I was done I figure I had about $1000 in it. I bought a new 5hp 1ph Baldor motor and a good quantiy motor starter because I wanted this to be the last compressor I every buy. I probably have another $200 in the cooler that is still to be mounted. The little things like fittings and a new pressure relieve valve do add up.

Since I've retired, it seems like I'm buying a number of things that are going to be "the last thing I ever buy" type things. Hmmm, interesting.