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New to forum, need Air Compressor help

8K views 11 replies 8 participants last post by  jenny watson 
#1 ·
Hello guys, I read all the AC posts and did not see any of the questions I have answered. I have an older quincy air compressor from an industrial shop it has a 3ph 5hp motor. I also have a 5hp 1ph baldor L1430T motor that is new. My questions are on the magnetic starter and pressure switch (both for the 3ph) will they work with the 1ph motor? If not can someone offer advice, I am not going to try to wire it myself just want to know what I am talking about before trying to hire an electrician. Thanks
 
#4 ·
As the other's have said, it'll work fine. Since it's a starter, it has over load protection on it and running 3 phase, the amperage ratings for the heaters is going to be too low. The single phas motor will have or should have it's own thermal protection. If so, you may be able to remove the over load section of the starter and wire directly to the contactor. If not, you'll have to install the correct heaters for the new motor's amperage. BTW, is the new motor compresor rated? It has to be as the are designed to start against a load. This is a dual capacitor motor, start/run. Other wise, when the tank has a partially filled, the motor may not have enough torque to get up to speed in time.
 
#6 ·
!st, those Quincy's are good pumps. The pressure switch, as stated above, is just a switch. 2nd, the motor should have it's own built-in starter. I converted a 3ph 10hp to 1ph 10hp, took the magnetic starter out of the circuit as the 1ph had it's own starter. This is a "farm duty" motor. It has a 60amp service to it and has no issues. I miss where the mag start is needed at all?
 
#7 ·
Highlander, I am no electrician but as I understand it the mag starter just helps control power needs during motor starts. I have been told that it will work without the mag starter, but it is more of a safety thing. I have noticed that on most of the new larger compressors have the mag starter. Right now I have about 325.00 in this rig. And you are right these old Quincy's Rock should be all the air I will ever need. :thumbup:
 
#8 ·
Quincy update

Just thought I would post an update on the compressor, got it temporary setup in my one car garage. My electrician put a 220 30amp circuit with a range plug and used a range pigtail to the magnetic starter. We plan to expand the garage this spring and will hardwire it then. The Quincy is amazing!, it will go from 0 psi to 175 psi in about 4 minutes, the pressure as set shuts off at 175 and on at 145. I hate to sound like a kid with a new toy but ,"Golly gee Mr. Wilson", I have for years just got by with an old sears "1hp" compressor it would inflate tires and run a 3/8 air ratchet or a spray gun but any thing else is too much for it. To put the Quincy to the test my son got out the pressure pot sandblaster ,I've had it for years and never got to use it, and blasted for three hours only stopping to refill the sand. It worked great never had to wait for the compressor at all. The only downside to the whole issue is that due to medical conditions I only get to watch,not to "play". Thanks to all for the information on air compressors :D :D
 
#9 ·
I know what you mean. I went from a craftsman 3hp single stage to a Ingersoll Rand 5hp 2 stage. I used to always have to wait for the compressor. Not any more. Now it the bolt wont come out it breaks it off. It one of the best investments I have ever made.
 
#10 ·
I realize this thread is a few days old, but I felt the necessity of adding this information about the magnetic starter. I am not an electrician, but my understanding of the purpose of the magnetic starter really doesn't have to do with starting the motor. It has more to do with stopping. With compressors being setup to turn the motor on when the pressure in the tank gets too low (ie: pressure switch), there is the potential, while your compressor is plugged in and turned on that the motor could be put in the position to run continuously. If a line/hose ruptured, someone drained the tank & forgot to turn off the power, bad pressure switch, etc. the motor would run continuously, and with the higher amp motors- true 5hp - they will run until they get red hot and potentially burn your shop down. Thats where the heaters in the mag starter come in. If it gets too hot, they will fail and the mag starter will go to the off position. The motor running continuously won't trip the breaker because it isn't providing any more power than it should. Anyway, that's my take. Be safe!
 
#11 ·
Toy, Good point, The starter or "drop box" is a relay to carry the heavy current so the lighter pressure switch only has to carry the light current needed to operate the starter. An extreme example would be the starter solenoid on a car which carries the starter motor load so the key switch only has to carry enough current to hold the solenoid closed otherwise the key switch would have to be VERY heavy.
 
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