A/C blower motor question..

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.

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

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

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.

groundhogy wrote:
I saw A.O.Smith? brand blower motors, but I didn’t see one for the Coleman ac.
I think they make really good hot water heaters. I had one last a, long time.

Hi, this may help,

The AO Smith brand was used in the Domeitic AC's or at least on the older Brisk Air units. I have not had one fail yet on the Brisk Air II so I do not know if they stuck with them.

Not sure if you knew, Coleman-Mach has a standard 2-year part and labor warranty. https://coleman-mach.com/service-support/warranty/

You said two seasons; I didn't know when the installation dates. There may be some warranty left on it. They may make you take it to a service center to pay for the warranty.

On the motor issues, by chance, while you are in AZ now, did the camper come back northeast into freezing temps since it was installed? Or go to north AZ where it does snow? I know some of the Dometics that live in the eastern winter states have an issue with the motor rotor getting corroded to the stator over the winter/springtime thaw. The motor sweats from the fast-rising spring temp on a frozen motor, condensation starts inside the motor, and it can lock up the motor in the worst case. This issue comes in different levels of binding, but it can give symptoms as you are stating. That said, this may not be the issue if your camper never went through a freeze/thaw cycle.

The compressor can sometimes have big and little capacitors on the compressor, with one being a hard start capacitor. The fan normally only has one capacitor, which has less start-up surge. There are ways to test the capacitor, some digital multimeters have a test on them, and the older analog meters can tell if the capacity is dead.

Heads up, when you get a new motor, which may be a different brand and model than the one you had, check the label for the required capacitor size; not all AC fan motors use the same size. You might have to change the capacitor to work correctly with the new motor as the size is different.

Hope this helps

John

I saw A.O.Smith? brand blower motors, but didn’t see one for the Coleman ac.
I think they make really good hot water heaters. I had one last a long long time.

I would check AO brand motors.
The other Cap is probably for the compressor.
I wouldn't think they need to be replaced.