OT: SLOW permanent split capacitor motor

Yes it could, but problems stemming from gummed up bearings are a far more likely cause.

Try spraying some WD40 or pentrating oil into the bearings just as a test.

Hopefully this will point to a problem with the capacitor, which is much easier to replace than are the bearings.

Harry C.

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I'd second the bearing hypothesis - I've seem a lot of these with sticky bearings.

If the capacitor is gone, it will run slowly for a while. then usually burn out if you leave it to long. Get another capacitor, they're pretty cheap.

When my central AC turns on, the fan starts slower until the evaporator chills then comes on full. It also slows down before shutoff, all by design. Does your fan ever get up to speed?

For a basic example of this consider some of the ceiling fan motors. Their speed is controlled via switching varying amounts of capacitance. Generally and AFIK, the capacitors come in multi-sectioned units with a lead coming out for each value. Each speed setting, usu. 3, has its associated cap value.

That's true.. capacitor values (uF) can affect speed and also the motor temperature. I tested some Oriental Motor PC motors recently for motor temp changes.

The motor's spec sheet might recommend a 10uF cap for one of their small motors (25-60 watt range), and specify the run time at 30 minutes. The motors run considerably cooler with a smaller value cap value of 2 or 4uF (wasn't checking speed change, there was no obvious noticable change since it was a gearmotor).

Other small induction motors used for portable fans may have no capacitor.

It's not typical for capacitors to change value by a wide margin. Shorted or open are more frequent, although internal (voltage) leakage is fairly common. High internal leakage is essentially a sign that it's on it's way to becoming shorted.

Testing for internal leakage is best done with an analyzer (or test circuit) that will test for leakage current at the actual working voltage. Ohm meters won't usually provide any kind of worthwhile test unless the cap is completely shorted.

WB ...............

1. Check the capacitor.
2. When was the last time you oiled the motor bearings? They don't have much oomph to start, and it may help if you oil the bearings well. If it was like mine was, you're better off taking the ends off of the motor and soaking the wicking material with oil under direct vision so it's well saturated.

RWL

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Thanks to everyone who responded.

I oil the bearings every spring with a Zoom oiler. I turned the fan by hand and it was smooth.

I removed the capacitor but unfortunately the markings wore off so I couldn't read the size. I tried calling Ruud (ie. Rheem) and they sure were rude. They said they didn't know and that I should check with their dealers. They gave me the phone numbers of two dealers. One said he supplies Rheem but not Ruud. The other guy said he doesn't deal directly with homeowners and hung up before I could say anything. I found a local Ruud dealer. The receptionist took down my information but no one called me back.

While searching the web, I happened to come across

and emailed them. A very helpful gentleman sent me a parts list which showed that I needed a 3mfd capacitor. I ordered one from them and UPS says it will arrive tomorrow. So we'll see what happens.

I'm not affiliated with Arnold Service in any way, but am very grateful for their assistance. I'm not affiliated with Rheem/Ruud either but don't plan to buy any of their products again if I can help it.

By the way, that web page has some very interesting reading.