Motor-start and motor-run are different but the same. A motor-run
capacitor is AC and is connected all the time. A motor-start capacitor
is connected usually through a centrifugal switch (and starting winding)
so it is only connected during spinup. There are many motors that have
centrifugal switches and starting windings without caps. and most of
the caps used are fulltime, that is run caps. Now, my definitions may
not be everybodys definitions, but that was how I was brought up when
I did motor repair and rewound armatures. The giveaway was the
original spec stated 60 cycle, which is a motor capacitor. run or start
is not significant, but if it said 60 cycle, then it cannot be a DC
cap with plus and minus.
As stated in a previous message, the capacitor "creates" a second phase
so you can get the motor to spin. Too little or too much capacitance and
the created phase is not in the proper angle to provide the right
rotation. again, make sure you get at least the minimum voltage, and
getting a cap with more voltage spec is o.k., if you cannot match
the capacitance, I think I would err toward more rather than less.
Joe Heck