Eric Murray wrote:
> On Thu, Sep 02, 1999 at 06:42:40PM -0400, Fred Zampa wrote:
> > Hello all:
> > I have two large Gilbarco gas station compressors
> > which I would like to run in tandem in the hope of getting enough air to
> > sandblast without frustration.
> > How do I go about hooking them up ?
My neighbor did this with a pair of 5hp
compressors, and it is not as easy as you might
think. If you just hook up the outlets, then only
one compressor motor will run (the cut-in points
will never match exactly), so as someone
previously stated, the second one is little more
than a second tank.
If you wire the limit switches together, or but an
extra heavy duty limit switch (heavy enough for
the concurrent start-up current draw of both
motors) to cut them in and out together, then they
will run in tandem.
However, you will need an AC circuit that is
"stout" enough to start both motors at the exact
same time -- this will place a very heavy
momentary surge on your breakers which may trip
them. You won't want to over-rate the breakers to
handle the start-up surge as then they would not
trip on an steady overload high enough to overload
Many of the shops that run two compressors have
each plumbed into a separate air circuit. This is
practical only if you have several separate air
lines in use concurrently (e.g., multiple
employees working at the same time), or they run
each one off a separate electrical circuit or they
run them continuously so that they don't put
concurrent start surges on the line.
I don't know which will work best for you, but it
will be more involved that just connecting the
outlets if you actually want to take advantage of
the second motor and pump.