In a message dated 7/1/00 9:02:50 PM !!!First Boot!!!,
105671.471@compuserve.com writes:
<< Speed is only part of the equation. Pump displacement is another and the
better compressors use larger displacement pumps and run them more slowly.
This gives better reliability and endurance.
Exactly! That's why I would take a 3hp 2 stage over a 5 hp single stage every
time.
Could it be that the low end manufacturers put a 5 HP motor on their
compressor but load it to where it only produces 2.5 to 3 HP in an attempt
to keep the current down to level compatable with house wiring? In this
way they can advertize "5HP!" without actually producing a compressor that
delivers 5HP worth of air. Just wondering. >>
Basically, that's the way I understand it. They have to use a 3450 RPM motor
to advertise a 5 hp motor. From what I recall, the 5 hp 3450s are drawing
like 15 amps, but the 1725s are drawing 30 or more. Also, if you notice the
shaft size on the 3450 RPM "5hp" motors, it is about half the size of the
1725s.
I spent a lot of time on this last summer. When my Sanborn piece of crap
threw a rod I thought I could just put a better pump on the tank. Simple huh?
Well, I could have replaced it with something similar but everybody I asked
said I could not put a 5hp Quincy pump on it because the motor wouldn't pull
it the way it was supposed to.
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