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Refrigerator evaporator fan oil.

NickD on Mon June 05, 2006 10:34 AM User is offline

Seems like others on the web are having the same problems using any kind of oil they can find for these sub zero operated shaded pole evaporator fan motors.

The original oil lasted over ten years, I tried Marvel Mystery oil, sewing machine oil, WD-40, 3 in 1 electrical motor oil, clock oil, an old can of electric motor oil, and this last time which was a mistake, SAE 10 motor oil, that only lasted a week and that little fan is making lots of noise again. Mounted in the freezer compartment above the evaporator behind a panel and an ice maker that is not easy to remove. Have the best success with the 3 in 1 electric motor oil, but only last about a year.

Same old story, ironic that such a tiny little 4 inch fan can make such a huge noise, take the fan out, let it warm to room temperature and it's perfectly quiet. Take the motor apart and just a tad of black gum on the motor shaft that wipes off easily with a rag. The wick is very large for such a tiny motor, use solvent to clean off the old oil, only about 0.002" clearance between the shaft and the bronze bearing with no signs of wear. One suggested using axle wheel grease, never did try Wolf's red grease, but that doesn't sound like a good solution. Ha, maybe no oil at all is the solution. Appliance dealers in town are no help, they just replace the motor and at 43 bucks, a pretty steep price just for a few drops of oil.

Anyone know of what kind of oil the OE's use in these sub zero fans? I had a similar problem with my dehumidifier fan that also lasted about ten years before making a racket and played around with it for awhile, the 3 in 1 electric motor is working great in that fan, haven't touched it in about ten years, but with other oils, only lasted about two weeks. Major problem is that gum buildup, the fan has never stalled like some claim to happen, fan was mounted with a bent "U" bracket to a sheet metal frame, I even enlarged the holes and installed neoprene bushing for sound isolation, but that was a waste of time.

Thought Amana was the best, been pleased with the drop in my electric bill, but this refrigerator has an impossible to clean condenser coil, forget about using a vacuum cleaner, no way to get in there with only three inches of clearance. After the first three months of use, only way was to take it outside and blow it out with an air hose. At that time, used window air condition filters on all the inlet openings that I have vacuumed. But after 12 some years, lots of fine dust on the condenser coils. Guess I have to take it outside again. Maybe time to shop again, love the condenser coils in my freezer under the cabinet, no fans, nothing to get dirty that has to be cleaned. Shouldn't mention MVAC condensers, another complete pain in the butt constantly plugged up with bugs and vegetation debris. We live in a dirty world.

MrBillPro on Mon June 05, 2006 10:53 AM User is offlineView users profile

Quote
Originally posted by: NickD
love the condenser coils in my freezer under the cabinet, no fans, nothing to get dirty that has to be cleaned.

Funny Nick I went out to the garage to look and possibly clean mine on my freezer yesterday and I could not find the condenser coil on my upright frigidaire were in the heck is that thing? It looks like it is covered up and sealed into the bottom of the freezer. You talked about cleaning your refrig. condenser coil I just bring the water hose in the house and put down a couple big towels in front of it and hit the coil 3 or 4 times with the water "my condenser coil is under the refrig." and it's spotless, I have been doing this for over 30 years on all my refrigs. works great.

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Don't take life seriously... Its not permanent.

Edited: Mon June 05, 2006 at 10:55 AM by MrBillPro

bohica2xo on Mon June 05, 2006 12:27 PM User is offline

Nick:

The oil you seek is instrument oil, MIL-PRF-7870

With a low temp stability to -54c, it will keep working for years. You probably drive by plenty of it on any workday. Used for aircraft instruments, the instrument shop should have plenty of it, and so will the propeller shop.

Here is the

EXXON spec sheet for instrument oil.


B.

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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

NickD on Mon June 05, 2006 12:30 PM User is offline

Interesting, true there is a condensate pan under there that is accustomed to getting wet, but I wonder about all that unnecessary wiring and electrical stuff that is right behind the condenser? I went back to the old type screw nozzles on my garden hoses as those spring loaded handle ones never seemed to last over a year, and yeah, my hand would get tired squeezing those, would create quite a mess trying to unscrew that nozzle.

I can feel the condenser lines on my freezer starts at the bottom left side of the cabinet, around the top and down the right side, loops up and down again for three coils and while running, has about a 15*F temperature rise, they must be glued or welded or soldered to the inside of the cabinet, not that curious to take it apart and look.

Any thoughts on the fan motor oil, that thing is going to drive me nuts!

MrBillPro on Mon June 05, 2006 12:47 PM User is offlineView users profile

Well you will need to use the spring loaded handle, the only thing that is even close under mine as for as any wires is the motor and it's way back in the left hand corner, it's a shaded pole so it only has two wire that are sealed pretty good, but I do it without even getting my motor wet just have to get my big million candle power light out set it there on the floor were I can see real good and go to town.

It don't take to many hits with the water unless yours is just extremely dirty, I keep mine cleaned about once every couple months and it takes about two big blasts and she is clean. Nick I did it this way on a double door big 26 cu.ft. kenmore for over 17 years and the only reason I just bought me a new one "the old one was still running great" is the thing was just rusting in some areas and the ice maker bit the dust,so I bought a new 26 cu. ft. one just like it on sale at Sears for $850.00 and gave the old one to my buddy for his garage were we go and play pool sometimes on the weekends.

Yea I guess you right about that cond. coil on the freezer it's tuck in there somewhere I hate that because I can see if it needs cleaned and hey they are proud of the big upright,self defrosting freezers I don't want to have to buy another one of those anytime soon.

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Don't take life seriously... Its not permanent.

NickD on Mon June 05, 2006 1:38 PM User is offline

I called my A&P friend, very well familiar with instrument oil and MIL-PRF-7870 for aircraft instruments and props, but sends that stuff out and doesn't have any.

One appliance dealer in town, a guy twice my age that is more interested in helping than selling does use 3 in 1 electric motor oil, but tells me, have to let the bearings soak in the oil for at least 24 hours, but never will last as long as the original as somehow that oil is built into the bearing. Ha, unfortunately, "instrument oil" on a google search is the same stuff used to grease a trumpet, hundreds of those to plow through.

Do I really need this fan? LOL. Bill is talking about his old refrigerator, mind was also over 25 years old when I got rid of it, mainly because of the clashing copper tone, that had a fan mounted in the refrigerator compartment with four easy screws to take out a plastic panel, but never gave me problems. I sold that one for fifty bucks, sold instantly because still looked like new so I wouldn't have to pay the 30 bucks recycling fee plus hauling to the dump. Was also super easy to vacuum out the condenser. One difference I noted in this new one is an extra thermal switch that shortens the defrost electric heater time to save substantially on electric cost. Should have added that to my old one and sprayed the cabinet, they don't make em like they use to.

MrBillPro on Mon June 05, 2006 6:15 PM User is offlineView users profile

Quote
Originally posted by: NickD
One appliance dealer in town, a guy twice my age

Dang Nick is his name Moses?

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Don't take life seriously... Its not permanent.

NickD on Mon June 05, 2006 6:28 PM User is offline

http://www.bocabearings.com/main1.aspx?p=quicksearchresultsFromCategory&pn=%25INSTRUMENT%20OIL

Is about the only site I found so far that sells instrument oil at more than a buck per cc, see Exxon sells it by the 55 gallon drum, ha, wonder what that price would be?

k5guy on Mon June 05, 2006 7:45 PM User is offline

LOL any oil seems to attract dust. Computer fans are the worst. We tend to use graphite.

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Send me e-mail

bohica2xo on Mon June 05, 2006 9:16 PM User is offline

Nick:

When I worked A&P, there were pump oil cans of 7870 on benches. It was the approved oil for fastener torque, we wiped passivated safety wire with it before twisting... pretty much used it for everything. Lockheed bought it in 55's, and did not treat it like gold. I used it for air tool oil.

If you are having trouble finding it, Kano Labs has a product called Microil - it has very similar specifications, and should work ok. I have used it for close fitting assemblies with good results. About 12 bucks a quart.


K5:
I don't see much dust in my freezer here in Las Vegas - is it a problem where you live?


B

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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

NickD on Mon June 05, 2006 11:38 PM User is offline

Again, thanks for the tip Bohica, getting a 404 not found error when I click on microil, will try it again in the morning.

Thought the purpose of the condenser fan was to route all the dust away from the evaporator fan and deposit it on the condenser coil so the evaporator fan won't plug with dust. The evaporator fan always is clean, just a tad of gum on the rotor shaft. Whatever dust the condenser fan doesn't collect is collected by my computers.

Bigchris on Tue June 06, 2006 4:15 AM User is offline

I always thought girls and dust were natural enemies. Are you saying they can co-exist?! I may want to sell my Swiffer stock!

NickD on Tue June 06, 2006 12:53 PM User is offline

Found a 7 cc tube of SuperLube at a local True Value store for three and a half bucks, a clear thin synthetic oil claiming to be gum free with an operating temperature range from -45* to 450* F. Thoroughly cleaned the motor and wicks and used up 1 1/2 cc's of this stuff, fan is quiet again, but the question is for how long?

With the engine oil in it, was extremely noisy, but quieted down to a whisper when the motor warmed up to near room temperature. Even when ice cold (-6*F) the fan blade spun extremely easily. I did add a 15 mil shim to take up some of the axially rotor slop. Just can't understand how a tiny motor like this can make such a loud irritating noise. The motor is mounted in rubber bushings, no metal contact via flanges on each end of the bearing mounts, and I added a couple of more bushings where the sheet metal bracket attaches to the rear of the freezer compartment. Plenty of clearance between the blade and the shroud and can't bend the motor far enough for the fan to hit the shroud, but at times, sounds like someone is sticking a playing card in the fan blades. All the screws are tight and can't hand rattle anything. It's a mystery to me.

k5guy on Wed June 07, 2006 6:59 PM User is offline

Quote
Originally posted by: bohica2xo

K5:

I don't see much dust in my freezer here in Las Vegas - is it a problem where you live?


Sometimes... but at least we are penguin free.

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Send me e-mail

NickD on Thu June 08, 2006 8:57 AM User is offline

Still curious about my RV refrigerator, 8.8 cubic feet, freezer that runs at -10*F, claims to be frostless, can't draw any more than 220 watts and the only way you can tell it's working is to open the door and feel if it's cold inside, dead quiet. Now that condenser can clean with a water hose, made for outdoor use, but doesn't seem to get dirty as it has no fan to suck in the dust.

NickD on Sun June 11, 2006 10:40 AM User is offline

First off, I am an idiot for even thinking a 0.125 inch motor shaft riding in a .127 bronze bearing can make that much noise, and a further idiot of thinking that a different motor oil will solve the problem. The problem is the idiots at Amana for installing the evaporator fan in the freezer compartment, as I pointed out before, this same fan was installed in the refrigerator compartment on my 30 year old refrigerator and never gave a problem. The problem is ice formation on the fan blades that I verified by manually running the defrost cycle to melt off that ice.

Now what is causing the ice formation, perhaps a teen age daughter that gets up at night and leaves the refrigerator door open, contrary to the instructions, from a perfect level, I raised the front of the refrigerator 1/8" so the door will close itself, also augmenting the problem is the constant rain we are getting this year, cool temperature with minimum AC running. From lessons learned, will never buy another refrigerator with the evaporator fan mounted in the freezer compartment, while the air movement is the same, least the fan sits in 37*F air instead of -10*F air so won't ice up.

To the engineers at Amana, you are idiots as I am for buying this thing.

FrankD. on Fri June 23, 2006 1:06 AM User is offline


Nick
Do you have any updates on the fan motor with the Oil Light Bushings?

Seams like I remember some one putting wax on the fan blades to discourage icing.


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FrankD.

NickD on Sun June 25, 2006 6:35 AM User is offline

Feel someone in my household wasn't closing the door, with the refrigerator perfectly level, the door just sits there until you close it, so I tipped it back by raising the front an 1/8" so the door closes on it's own, seems to have solved the problem. This never was a problem for me until recently, I did wash off the fan blade. Now you got me wondering if it was coated with some kind of wax, and what kind of wax would that be?

NickD on Mon October 30, 2006 6:46 AM User is offline

Enjoyed near quiet operation from the fan for several months now, but then got an annoying vibration, pulled it again, lots of slop in the bronze bearings. Now you cannot go out and buy bronze bearings for 15 cents a apiece like they use to sell, have to buy a new shaded pole motor. Amana wants 70 bucks plus another 15 bucks S&H and taxes for this piece of crap motor.

Went to my Fleet Farm store and purchased a bathroom ventilator fan for $9.99, had a very nice A.O. Smith motor in it of better quality than the the Amana, even has oil holes in the bearings so you don't have to take it apart. Shaft was 3/16", so had to pull that and turn the fan section down to 1/8", less than a five minute job. Also added a four buck speed controller to it.

All went very well, but between phone calls, interruptions, etc. really went brain dead and forgot to check the direction of the motor, ha, woke up the next morning and my milk was a bottle of ice. Dang, pulled the motor out again and only have to reverse the rotor to change directions.

The lower freezer unit has the compressor thermostat mounted, I set that to 0*F, could set it at -12*F, but my wife has to use an ax to scoop out ice cream, we only use this freezer for short term items, at 0*F, soft enough to be conventionally scooped. Upper refrigerator temperature control, first dependent on the freezer temperature has a box with two vanes on the inside. The upper vane is opened directly by the temperature control knob for colder temperatures. This same knob is mechanically thermostatic that varies a lower vane to maintain the box temperature. Made me wonder why they didn't use this thermostat to run the evaporator fan.

With the added speed controller, was able to reduce the motor speed by about 25% to get rid of that high pitch whine and open the vanes about that much more to maintain the interior at 37*F to accomplish the same thing, just a whisper now when the compressor kicks on. Evaporator fan is in parallel with the compressor and runs whenever the compressor is on. Compressor is very quiet as is the condenser fan, was that evaporator fan making all the noise.

Hopefully, will operate now for awhile, these replacement parts cost are getting positively insane. On my motorhome, had to pay 45 bucks for a 200 watt heater with a couple of wires on it. Replaced my 15 buck coffee pot and took the old one away for parts, couldn't help but notice that heater was cast aluminum, 1100 watts and made far superior to the one I paid 45 bucks for my motorhome refrigerator. That was just a 3/16" 10" long tube with the nichrome wire on the inside with a couple of wires hanging out, no where near the quality of the one found in my 15 buck coffee pot. Naw, the coffee pot heater won't fit in my refrigerator, but maybe will find a five buck complete product that has a similar part.

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