Go here http://www.chpower.com/ ... look at item 32 looks like a relief
valve or unloader , then start pump while pulling ring on relief valve ...
if pump starts you got it , get new valve... if not then I would contact
them.
If you keep up what your doing and smell something like burnt paint... it's
the motor.
4 hp sounds like a BIG motor for 220 single phase ... what's that thing draw
?

"Bruce L. Bergman" wrote in message
...
On Sat, 27 Nov 2004 21:35:47 GMT, "habbi"
wrote:

After ruling out any and all pressure, check valve etc... problems I took
off the end of the motor and fiddles with the thing in side that switches
from start windings to the run windings. After I put it back together it
seemed to work better. In hindsight it did seem to start slow even when
the
tank was empty but now it is like it used to be, almost instant start up
at
any pressure. What could have been wrong. Could it have been trying to
start
on the run windings? Can the capacitors get weak or do they just die?

If the centrifugal start switch was stuck in the Run position, it
would never cut in the start windings when it spun down - do you now
hear a distinct "click" as the motor starts up, and another as it
coasts to a stop?

It might have been able to start the motor on the Run windings alone
with no air pressure in the tank, but with any backpressure at all
past the check valve it wouldn't go. It wouldn't reach speed before
the tubing between the compressor and the check valve pressurized and
stalled the motor.

I had to cheat to make an airbrush system out of a 1/3 HP diaphragm
compressor that could not start reliably against head pressure - used
a 10-second cam-switch motor sequencer, a self-latching (drop-out)
motor relay and a solenoid valve for the unloader. Leaving the
unloader valve open for 5 seconds after motor start (until the motor
came up to speed) allowed it to work every time against a tank and
check valve.
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
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