"Foo" wrote in message ...
A few years ago, the motor capacitor from my pressure washer exploded,
it was a large 50uF non-polarized, plastic-cased run capacitor for
a 230V, 2750W motor. Interestingly, it didn't stop the motor right away
but it couldn't restart when shut down.

Its case read ILCEA K 45 5000 50uF +/- 5%b 450V HPFPU.

Because the device was over ten years old, I didn't bother to repair
it but kept it anyway, until a few months ago when someone gave me four
large alumin(i)um-cased caps: 13uF 13uF 14uF and 10uF (non polarized,
450V max or so, all from Bosch).

So I decided to wire them in parallel in place of the old one, and it
worked as before even under maximum load.

After 10 minutes of use, I stopped the motor to make sure the capacitors
were not overheating and found that the two 13uF caps were hotter than
the others (still able to touch them with my bare hand, but the two others
were still at room temperature).

Does it mean that only those two actually work, do you think it's safe
to continue operating the device, or will they keep heating up until they
meet their fate too?

Thanks.

--
Foo
One thing that I haven't seen anyone else mention is that start caps are
often non-polarised electrolytics, identifiable by an aluminium case with a
rubber plug, but run caps are always low loss types, typically film; an
electrolytic cap used as a run cap will overheat and will probably explode
sooner rather than later. Given that your caps are running hot, I would
think it is a cap-run motor.
Farnell do sell 50uF 450V working film capacitors for motor run use, I have
several of them in my rotary phase converter; the price was not
unreasonable.
Martin
--
martindot herewhybrowat herentlworlddot herecom