A/C blower motor question..

[groundhogy]

Here in Arizona.
Blower motor lasted about two summers after new Coleman Mach install. Now its making noise and is hard to turn.
So i guess if its 115 degrees outside, it must be alot warmer than 115 inside the A/C cover.

Looking online, i see several brands of replacement motors.
Broad-ocean hai phong (viet nam)
NBK (Ameri ?)
Fasco (made in mexico)
Altran Magnetics (china)

Q: is one brand of better quality than the others?

I see two capacitors under the cover. The small one is for motor start.
Q: whats the big cap for?

Q: caps are only two years old. Do they need to be replaced also at this time?

[groundhogy]

Yes ive seen the reference to turbine oil a couple times.
One person said it is distilled more times and so has less dissolved stuff in it?

Another said grease is a no-go as it dries out very quickly leaving behind all of the thickeners.

[ernie1]

Years ago I had a clothes dryer that had a squeaking blower motor bushing which was an oilite bushing. I was told by repair shops to just reoil it with turbine oil. When I went to buy turbine oil I saw that it was just this oil that seemed to be about 20w motor oil. So I thought that was a bad recommendation and put heavy grease on the bushing instead. Well this worked for about 4 or 5 cycles and the bushing started squealing again. So I tried STP oil instead and, again, it lasted. about 4-5 cycles before It would start squealing again. So, out of desperation I finally tried the turbine oil almost knowing it was going to fail. But it lasted for years until I sold the old dryer and bought a new one. I was told that turbine oil can operate at temperatures higher than regular lubricants. Must be true!

[groundhogy]

Yes, i purchased a Fasco motor and it is in transit.
From Electric Motor Warehouse.

Those are good ideas. Maybe i will recondition the old motor and then try to rotate them.
In Arizona, it often gets to 115 deg ambient, so inside the AC cover, where it is shedding heat from the RV, its gotta be punishing temps. Ive heard people say the motors last 1-2 yrs. (car batteries only last 3-4 here...)

Cooking the bushings... i like that

I had my furnace blower motor out (PA winter where the furnace runs constantly), and was seriously thinking on how i could retrofit some ball bearings on the thing.

PA too cold
AZ too hot

[ktmrfs]

the blower motor on our coleman lasted about 10 years, then started to emit a low pitched whine for a while on startup. Original motor was a FASCO, bronze oil lite bushings were dry, replaced it with another FASCO motor.

BTW FASCO motors are in our home AC and NG furnace, both over 20 years old and still purring along.

[Joe417]

If you are mechanically inclined and you can tell the shafts and bushings are fair too good.

Our 2005 Coleman blower shafts dried and were loud in 2016. Motor shafts were stuck on both motor ends. Both sintered bronze bushings released by drilled rivets holding them on the motor ends. Cleaned dried grease from both shafts and bushing to release from both ends. Heated both sintered bronze bushings and dipped in grease and allowed grease to cool. Put bushings held back on motor bell ends using small screws rather than rivets. Reinstalled the motor on the AC and has been working for about 8 more years.

I think a replaced motor back then about something like $180.

Much more than about 2 hours for my time and no $.

[sayoung]

Mr. C wrote:
There's nothing wrong with Fasco motors. They're very popular in the HVAC trade as replacement motors...

Fiasco is a motor I had very few problems with when I was I was working. Seems like Fasco was the only double shaft aftermarket motor any of my suppliers carried.
I used a Fasco on my 10 yr old Coleman 2 years ago. I allways replaced the run capacitor when installing new motor

[Mr__C]

There's nothing wrong with Fasco motors. They're very popular in the HVAC trade as replacement motors...

[groundhogy]

........ and, I just zoomed in on their product picture.

they are showing a picture of a Fasco motor on the AO Smith product page.

[groundhogy]

oops.. heres their website

http://www.tek4ufast.com

They want about $50 more than the cheap blower motors that are available. Also, their website seems legit, but none of the little safety icons at the bottom of their website. No paypal either.

[groundhogy]

I only find these folks selling Century (formerly AO Smith?) brand blower motors for the Coleman Mach (foil tag shows this model no. 48204-666).
I have what looks like the most basic/common Coleman AC.

[groundhogy]

Hi John,
I think its just dried out bushings because when I spin it by hand, it does spin, but stops very quickly. There is no other rubbing occurring.

[JBarca]

groundhogy wrote:
That helps alot John.
So that seems like two votes for the AO Smith. I will try to find one of their motors.

The other issue is how fresh is the motor off the assy line? Those sleeve bearings are just soaked in oil so won't they dry out over time?

Also... you guys just reminded me.. I bought one of those EZ Start kits and never installed it. I should dig that up.

Yes, I did return to Pennsylvania for the last summer season. The AC ran, but that is when I started to notice what seemed like blower motor noise. I went up on top the other day, and the motor does spin if you use your hand, but it doesn't spin freely. There is significant friction.

Hi ground hog,

The bronze bushings with oil, odds are high that those are oil-impregnated sintered bronze bushings. In the industry, they are nicknamed "Oiltite bushings" as Oilight was one of the original inventors. These guys, I think, were bought out along the way. https://oilite.com/oilite-all-products

There are many brands now that sell oil-impregnated sintered bronze bushings. The heat of friction draws the oil out of the bushing to keep the bushing lubricated. If the bushing brand is good, I have seen AC units last 20-plus years with those bushings.

Now to your drag and noise; by your description, you might have a problem other than the bushings that can create excess drag and noise. Coleman Mach shows they are using a prop fan on the outside and a squirrel cage fan on the inside. I do not know your model, but here is a parts list on a Mach 3 + a common TT AC unit. https://www.airxcel.com/DesktopModules/RvProduct/Pdf/r667.pdf

The inside squirrel cage fan may have shifted and is rubbing on the housing. I have not worked on the Machs, but I have on the Dometics, which are built, in concept, close to the same. What led you to believe it was the motor bushing versus a fan wheel rub?

Again not knowing your AC model number and not being fluent with the Mach's, I'm not sure if you can see up at the squirrel cage fan from inside the camper with the air box removed or if you have to go in from the top down without much work. Maybe one of our other guys who have been into these can tell. On the Dometic, I know you can get in not too hard from the top down, pull the cover and the blower housing cover off, and the fan is exposed to see the inside fan wheel.

Hope this helps

John

[groundhogy]

Found this...

Smith's electric motor division, which completed in 2011. The motors made in the former A. O. Smith plants in Milwaukee and Tipp City now carry the "Century" brand.Jan 26, 2021

[groundhogy]

That helps alot John.
So that seems like two votes for the AO Smith. I will try to find one of their motors.

The other issue is how fresh is the motor off the assy line? Those sleeve bearings are just soaked in oil so won't they dry out over time?

Also... you guys just reminded me.. I bought one of those EZ Start kits and never installed it. I should dig that up.

Yes, I did return to Pennsylvania for the last summer season. The AC ran, but that is when I started to notice what seemed like blower motor noise. I went up on top the other day, and the motor does spin if you use your hand, but it doesn't spin freely. There is significant friction.