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 Posted: Mon Aug 16th, 2021 08:24 pm
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Zac Kiebke
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Hi,   I recently cleaned up an emerson 77646-AS and gave it all new lubricants.   It's in pretty good shape and wasn't that dirty even the grease wasn't all solidified.  The one thing that was bad is that it had evidence of water dripping down on its head and the bottom plate had pretty good rust to it.  see picture of rust locations.The problem I'm having is that it runs but only very slow on slow and medium.  high is better but I'm sure its not at full capacity. 
My guess is the capacitor got damaged by sitting at the bottom of the base of this fan in water at some point.  I think this is a 'run' capacitor and from the wiring I can find, it's always connected no matter what speed.  so maybe this item is therefore affecting all the speeds.  
Any help would be great!

Attachment: (Downloaded times)

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 Posted: Mon Aug 16th, 2021 10:04 pm
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Mark Olson
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The capacitor may well be the problem. Replace it with a 2.5 MFD @ (at least) 200 volts.Higher is okay. The local A/C parts store may have one rated at 370 or 440 volts, or Ebay, etc.

Last edited on Mon Aug 16th, 2021 10:07 pm by Mark Olson

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 Posted: Mon Aug 16th, 2021 10:49 pm
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John McComas
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77646 .42 amp on nameplate original was 1.7 mfd or uf at 250 volts.
With todays slightly higher voltages, a 1.5 mfd or uf  at 400 volts or more is recommended.

https://www.ebay.com/itm/273514282662
https://www.ebay.com/itm/273514282763?hash=item3faeb8bf0b:g:OpAAAOSwHSRbyKij

Last edited on Tue Aug 17th, 2021 05:31 am by John McComas

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 Posted: Tue Aug 17th, 2021 12:16 pm
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Zac Kiebke
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Thank you both! I'll try the 1.5 cap and see how that goes. Does it matter what direction the leads are connected? I see both are black on the one example and there has a red and white lead.

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 Posted: Tue Aug 17th, 2021 02:34 pm
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John McComas
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Zac Kiebke wrote: Thank you both! I'll try the 1.5 cap and see how that goes. Does it matter what direction the leads are connected? I see both are black on the one example and there has a red and white lead.

These are non-polarized, or AC capacitors and lead connections do not matter.
The old oil filled capacitor may have PCB oil, (a carcinogen), and I replace them with the Mylar film type.


Emerson 77646 is one of the most efficient, best designed fans of its era.
Happy Fanning!

Last edited on Tue Aug 17th, 2021 02:52 pm by John McComas

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 Posted: Wed Aug 18th, 2021 10:38 pm
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Zac Kiebke
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the new 1.5 cap got delivered fast. I cut off the old and hooked up the new one and it unfortunately it runs the same way, no change. all speeds are slow/ weak... seeing the evidence of some water damage to the outside I wonder if there is anything that could lead to inside that is causing the problem. Also, the center motor portion was black. sorry no picture of it. I expected it to be exposed metal. are they supose to be black on these? is there a glazing that can happen to those causing a less effective motor?

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 Posted: Wed Aug 18th, 2021 10:42 pm
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Mark Olson
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Does the fan spin freely by hand? Or is it rather stiff to turn?

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 Posted: Thu Aug 19th, 2021 04:23 am
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John McComas
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I would also check for headwire continuity.  You should have resistance between each headwire.

https://www.fancollectors.org/info/mccomas/Emer_77646-AS.jpg


I say check headwire resistance because the wires deteriorate where they come out of the base
due to years of oscillation movements.

Do not put grease in the motor bearings!  Grease only goes in the gear box, and do not fill the gear box.
just enough to coat all the gear teeth.

You should not use any grease or detergent oil in the motor bearing.
20 SAE non detergent like 3 in1 blue can, or Zoom Spout turbine oil.
Synthetic non detergent ~ 20 SAE is also OK to use.
Happy Fanning.

Last edited on Thu Aug 19th, 2021 01:25 pm by John McComas

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 Posted: Thu Aug 19th, 2021 12:20 pm
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Zac Kiebke
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If I compare it to other fans it is be a bit stiffer to turn.  I did use some royal purple (max tuff) assembly lube in the bearing areas when I cleaned and reassembled it.  It did run the same way before I cleaned it.I read something last night trouble shooting a slow fan. mechanical: loss of bearing lubrication or poor blade balance. My blades are fine.  Electrically: bad capacitor (just replaced the cap) or damaged winding.  Yikes, I hope its not the winding...

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 Posted: Thu Aug 19th, 2021 02:13 pm
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Zac Kiebke
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Ok, I will check the continuity and see what readings i get.  sounds like in other sites/videos i looked up the head wire gets replaced a lot on these emersons.  I should just plan to replace it. It just looked in better condition than most other brands but the head connections sound vulnerable to wear.   I see 16 gauge 3 breaded wire at vintage wire and supply.  sound right?I'm making all classic mistakes!  I packed the grease housing, so I'll fix that.  It was packed when I originally opening it up.  maybe this was lubed before and the previous owner over packed the gear box as well. I'll also clean out the bearing and only use zoom turbine oil.  my bad...
thanks for your help!

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 Posted: Fri Aug 20th, 2021 03:52 am
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Noah Britt
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18 gauge wire would be standard for a desk fan, but 16 isn't a problem as long as it fits through the grommets. If you haven't bought the wire yet, go for 18. I also don't see how packing the gearbox with grease would hurt anything, but I would be grateful if someone could enlighten me as to why that is a problem.

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 Posted: Fri Aug 20th, 2021 04:12 pm
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John McComas
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Noah Britt wrote:  I also don't see how packing the gearbox with grease would hurt anything, but I would be grateful if someone could enlighten me as to why that is a problem.

"Packing" the gearbox with grease is not the best thing to do...
You are making the gearbox into a butter churn.  (Old age showing)
Think of it this way:  Hand crank ice cream maker turns easily when it is empty.
It turns harder after it is loaded.  Even harder to turn when it's turning to viscous ice cream.
Packing a gearbox with grease puts additional unnecessary load on motor and creates wasteful heat.

Gears only need lube on the gear teeth, and the gear bushings.
The maximum lube is needed on the worm and bull gear teeth. 
The sliding teeth create the most friction.
The other issue is that with speed, the lube migrates, (gets slung) out of the gear teeth.
Also, if the grease separates into oil and the carrier (I think they call it soap) the oil evaporates
and you got friction.  The best thing to do is to force grease down in between the teeth.
I use "Red & Tacky" grease for gears and low speed bushings.

I would not use grease in Emerson single bearing shafts or rotors.  The only exception would be
to stick a little bit in the Emerson hub slot for the oscillator rod to prevent it from clicking.
I hope this helps with gearbox lubrication.
Happy Fanning!

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 Posted: Fri Aug 20th, 2021 05:26 pm
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Noah Britt
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Thanks for the explanation! I will definitely keep that in mind when lubing gearboxes in the future.

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 Posted: Fri Aug 20th, 2021 05:55 pm
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Zac Kiebke
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I have some gear boxes to go though this weekend! thanks :)

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