On Wed, 6 Aug 2008 12:05:57 -0500, "Dan K"
wrote:


"Tony Hwang" wrote in message
news:R7jmk.60851$nD.49208@pd7urf1no...
Dan K wrote:
Our 3000 gal/hr submersible pond pump failed to start a couple times.
Once it started after 1/2 hour or so, the other time I was there and
unplugged it and it started when I pluged it in again, but it was hot to
the touch. I took motor apart. Its an oil filled pump and it looks
brand new inside. Oil was clean, no water in it. 13uf capacitor, listed
as "motor start capacitor" in parts list, reads 13.6 uf on a capacitance
meter. I'm not sure what to do next as I don't see anything wrong. I
was thinking of replacing the capacitor just because I know they can
fail, but that value is hard to find. 12 uf and 15 uf seem to be
readialy available, would one of those work? Anybody have any
suggestions as to what to do? No brushes in this motor and bearings,
seals, and gaskets are in great shape. Thanks

Dan
Hi,
By theory if you can't find exact value cap. Use next one up. Any how
those caps have very wide tolerance like 13.6uF +/- 10% for an example.
15uF should do fine. Is the cap can bulging? Typical sign of failing cap.

No bulges, the cap looks almost new (like everything else in the motor).
Its not a can (oil fill type), its the dry film type - plastic case with
epoxy fill.



I had a similar problem on a spa pump motor; wouldn't start by itself,
but if I spun the shaft manually to get it going, it would run fine
until powered down. Like yours, the starter cap tested ok. In my case
it turned out to be the contacts on the centrifical switch that
brought
the starter cap in at no/low speed. After cleaning the contacts
on that switch, the motor started up fine. Still running fine many
years later.

-beck