Field Controls PV Motors

DuMass

I wonder who the genius was that decided to make the newer Field Controls SWG4/5 replacement PV motor kits without oil ports for the motor bearings. It seems ironic how they stress the need for annual PV maintenance and cleaning of the blower wheel, but then they do away with what is probably the most important aspect of this maintenance.
These things are not cheap and the old Fasco motors would last for many years if you routinely added a few drops of turbine oil or the special FC silicone oil during the annual cleaning.
I installed one of their new and improved oil-less ones less than two years ago and naturally it’s starting to make noise already. I’m not sure if it’s motor bearing or just the smaller motor cooling fan blade inside making contact with the housing, but I will find out when I tear it down next week.

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user2561

**This response is speaking in relation to lite duty motors (3/4, etc)**

Sealed motor bearings have been in use for some time and actually, generally have performed quite well. Of course there are times when they fail as does the serviceable motors.

Those in engineering have found that when looking at all factors, oil less or sealed motors last longer. There are a number of reasons behind this...mainly the huge volume of misunderstanding by service technicians in regards to proper oiling. Many times techs over oil, leave out the plugs allowing contaminants (rain on outdoor units or condensate spray on indoor units) to enter bearings sleeve, and use of improper oils for lubrication.

Obviously, there are those who utilize and service the serviceable motors properly but there are far more that do not. This causes a much larger rate of failure in those motors with the "unsealed' bearings.

Saturatedpsi

I've seen a few new condenser unit fan motor bearings fail within the first year. New aftermarket replacements with sleeve bearings were lasting 2-3 years. I finally gave up and began buying ball bearing motors. Jury still out on the lifespan of those.

DuMass

So, in this particular case it turned out to be the blower wheel itself. Some of the blades on the squirrel cage had somehow loosened up to the point where they were vibrating when the motor was running and the noise was telephoning through the stack pipe back into the house. Replaced it with a new blower wheel and all is well… and quite.

This does seem a little bit strange however, because the blower wheel wasn’t out of round and the factory balance weights were still in place. To my surprise though, the motor bearings themselves were still fine with no noticeable shaft end play. So, I guess that's score-one for the big brains at Field Controls and Fasco.

__________________
"My, what a beautiful lawn you have... for me to poop on!"

[Triumph the insult comic]