In article ,
Jamie t wrote:

b wrote:
a friend is having problems with the pump in an outdoor pool.
Apparently the motor ran one day then the next day it would not come
on. mains supply is good. He suspects a capacitor - which seems to be
16uF 400v , from the motor. I've seen it, quite a chunky thing with a
small threaded screw coming out of it for attachment and a plastic
body. it's about the size of the mains filter caps in 1970s t.v.s

I had never seen a 16uF cap before, and I am surprised at this size.
Is it likely to be an electrolytic? I presume replacing this is a
good place to start. Any thoughts?
-B
IT's a AC (Non polarized cap) and you can't always assume a cap.
You can look for vented internals at the base ect.

Also a good test would be to see if the motor is humming when started.
if this is the case then the CAP maybe opened but I would first check
that. The caps are not cheap.

About $7. Many people would call that cheap.


Use a CAP meter or your DMM which many have a C testing function.
check for DC shorts and then test for Value using a Cap function .

Also, some motors use a centrifugal switch that sits in the head of
the motor. The actuator/switch could be stuck or broke. You can
determine this
by using an ohm meter from the windings verses the other windings..

etc..

The centrifugal switch contacts on my compressor motor were
intermittent, and I ended up replacing the switch. But I don't consider
the few dollars I spent on new caps as a first attempt, to have been
wasted.