pool pump motor capacitor question

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.

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..

In my experience when the start capacitor fails, the motor will turn slowly, but never kicks up to speed. Some motors also have a run capacitor.

The start capacitor on all 1 hp motors I've had was always rated 161-193 mfd. Can't tell you what a 16 MFD would be.

The capacitor is almost always suspect in case of an AC motor failure, however, it's not the only thing that can cause problems. As a starting place, I suggest that you read the FAQ at

If the motor has a centrifugal start switch, then that's the first thing to check, since it's the easiest thing to get to on your motor. Open the end bell on the opposite end of the shaft and make sure the contacts are in good condition. If they are burned or badly pitted, they are probably not making contact. This will surely prevent the motor from starting. Next, test the capacitor with an ohmmeter. It should not have a steady low (less than a few thousand ohms) resistance, but when the meter is first connected, the reading should read very low, then commence a steady rise in resistance, ending in extremely high resistance. Last thing for you to try is check the continuity of the motor's windings. The web page above will give you a number of possible wiring configurations (you'll have to determine which applies to your motor).

Why does he suspect it?

Limited experience?

Too small or too large?

Good for the person who sells you a new capacitor. Probably not good for you, however.

More information, what diagnostic work have you done yet?

About $7. Many people would call that cheap.

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.

Smitty Two ha escrito:

thanks for the useful replies.- part of the problem here is that I'm working 'blind' , not having seen the setup or been able to check it out for myself, I don't even know what type of motor it is or how old etc. All I've seen was the cap that was shown to me briefly. I'll try and get out there to take a look for myself and post back. meanwhile will follow up on the links and advice posted here. cheers, B.