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Post by beschen on Mar 13, 2023 22:40:52 GMT
Hello All,
Beginning to dig into my Mills Coca-Cola machine's refrigeration system from 1941... This is a belt driven system w/ a Wagner electric motor.
Removed the motor only to find it does not run when powered on but the motor spins freely by hand... The capacitor atop is an Aerovox and I have located a few NOS capacitors for replacement; however, is there additional testing that I can perform prior to spending money that may or may not revive this motor...?
Thank you for your time!
Jim
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Post by ckfan on Mar 13, 2023 23:18:45 GMT
It sounds like you’re on the right track and in the right place. David Allen knows a lot about motor, open belt drive compressor, and refrigeration repair in general. I’ll let him step in. I’m sure you’ve already done the basic stuff like lubricating the motor with a product similar to 3 in one electric motor oil, in the blue can.
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Post by turbokinetic on Mar 13, 2023 23:33:44 GMT
Hello All,
Beginning to dig into my Mills Coca-Cola machine's refrigeration system from 1941... This is a belt driven system w/ a Wagner electric motor.
Removed the motor only to find it does not run when powered on but the motor spins freely by hand... The capacitor atop is an Aerovox and I have located a few NOS capacitors for replacement; however, is there additional testing that I can perform prior to spending money that may or may not revive this motor...?
Thank you for your time!
Jim
Totally awesome! I love the vintage vending stuff as well. Please, by all means, share some pictures for us! The motor will have a centrifugal start switch inside it, to switch the capacitor on and off. That might be gummed up or worn. I would inspect that carefully before trying to run it. Also, be sure the motor is properly lubricated. The oil dries up over time. In general, if the motor wining isn't burned, it will work with proper auxiliary parts such as the start switch and capacitor. If the centrifugal switch is bad, that can be removed and replaced with a potential relay start device too. Sincerely, David |
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Post by beschen on Mar 14, 2023 18:13:17 GMT
Thanks for the replies!
I was surprised the motor spins freely but when energized, it just hummed briefly as I shut it down quickly!
Guess it's time to crack the case and see what may be the issue... I forget... Should there be a resistance reading across the hot/neutral terminals? If so, roughly where would it be in ohms? Nothing appears to be shorted to the case/chassis... I'll check the start/centrifugal switch once I open her up... Although, I have other old motors with centrifugal switches and there doesn't seem like much to go wrong with one...
I'll get some photos on my next post...
Many Thanks again! Jim
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Post by turbokinetic on Mar 14, 2023 21:59:11 GMT
Thanks for the replies! I was surprised the motor spins freely but when energized, it just hummed briefly as I shut it down quickly! Guess it's time to crack the case and see what may be the issue... I forget... Should there be a resistance reading across the hot/neutral terminals? If so, roughly where would it be in ohms? Nothing appears to be shorted to the case/chassis... I'll check the start/centrifugal switch once I open her up... Although, I have other old motors with centrifugal switches and there doesn't seem like much to go wrong with one... I'll get some photos on my next post... Many Thanks again! Jim Hi Jim. There isn't much to go wrong with centrifugal switches, other than old oil and grease gumming up the moving parts. That is likely to be an issue. Once that happens, it sticks and then keeps the capacitor in the circuit leading to damage. It often lets the smoke out of the capacitor; which may be what happened to yours. Hopefully the capacitor is all that's wrong. As for resistance measurements, the motor should have a solid closed circuit across the two input wires. It should be around 1 to 4Ω on a meter. Measuring from either / both of the power wires to the frame of the motor should be an open circuit, or at minimum 1.25MΩ of resistance. |
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Post by beschen on Mar 15, 2023 1:43:12 GMT
Thanks for the reply David! Nothing to really report for an internal motor check; switch appeared to look good and move freely as did the centrifugal mechanism... Found a little furry friend that decide to take a nap and never woke up! Tomorrow, I'll meter the terminals again, but I think I remember it metering around 3.3 ohms which to me seems fine. Nothing to chassis/ground. I guess I'll order a new capacitor, install it and see if that helps getting this motor running...
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Post by turbokinetic on Mar 15, 2023 2:28:04 GMT
Thanks for the reply David! Nothing to really report for an internal motor check; switch appeared to look good and move freely as did the centrifugal mechanism... Found a little furry friend that decide to take a nap and never woke up! Tomorrow, I'll meter the terminals again, but I think I remember it metering around 3.3 ohms which to me seems fine. Nothing to chassis/ground. I guess I'll order a new capacitor, install it and see if that helps getting this motor running...
Wow! That is an absolute beauty. Very early and primitive and I love it! Trying to identify the compressor manufacturer. It may be Kelvinator but I will need to look at some other drawings tomorrow to confirm. How well does the compressor turn? How's the shaft seal? |
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Post by ckfan on Mar 15, 2023 14:53:06 GMT
I love the look of this vending machine. Very cool. Almost looks like a gas pump.
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marko
7 Cubic Foot
Posts: 141
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Post by marko on Mar 15, 2023 23:06:58 GMT
Oh yea! That is a beauty! What does it take? A nickel? A nickel is the cheapest Coke that I ever remember, with the Coke machine at our old church running a close second at a nickel and a penny.
Those naked spots on the run windings are a bit concerning. Get up with me if you determine that it needs a rewind. I don't see a centrifugal switch in the picture.
Oh wait... my bad, I see what may be part of a centrifugal switch on the back of the rotor. |
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Post by beschen on Mar 18, 2023 19:17:50 GMT
I appreciate your replies! Thank you!
Well, good news & bad news...
First to answer any question you'll may have asked:
David,
The compressor is stamped with "Mills" in the casting. Mills did build a lot of their components whether refrigeration, electrical or other technical components; however, maybe they outsourced some components, I don't know... Photo shows the data plate. As for the shaft seal, I cannot see it easily, but the pulley rotates smoothly by hand.
Marko,
It's a 5 cent vendor and only accepts nickels. The actual centrifugal switch is located in the rear motor housing. The actuator is what you see on the tail end of the motor shaft. Interesting design.
Good news first - The capacitor replacement started the motor; so, I know the motor works as it should provided it's spinning in the correct direction, clockwise, looking at the motor shaft/fan blade. Bad new is that the capacitor unexpectedly "popped" with a loud crack and some "sh@%t" hit me in the face! Fortunately, my glasses caught the small debris! The capacitor still looks to be intact except for leakage along the top edge. Interestingly and as adventurous as I am, I turned the motor on again only to find it still functions... However, the capacitor gets hot and produces the proverbial "smoke test" in seconds!
Pictured is the original and replacement capacitors for your review, but I think the parameters are very similar!
Any direction/suggestions welcome... |
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Post by turbokinetic on Mar 19, 2023 2:01:08 GMT
I appreciate your replies! Thank you!
Well, good news & bad news...
First to answer any question you'll may have asked:
David,
The compressor is stamped with "Mills" in the casting. Mills did build a lot of their components whether refrigeration, electrical or other technical components; however, maybe they outsourced some components, I don't know... Photo shows the data plate. As for the shaft seal, I cannot see it easily, but the pulley rotates smoothly by hand.
Marko,
It's a 5 cent vendor and only accepts nickels. The actual centrifugal switch is located in the rear motor housing. The actuator is what you see on the tail end of the motor shaft. Interesting design.
Good news first - The capacitor replacement started the motor; so, I know the motor works as it should provided it's spinning in the correct direction, clockwise, looking at the motor shaft/fan blade. Bad new is that the capacitor unexpectedly "popped" with a loud crack and some "sh@%t" hit me in the face! Fortunately, my glasses caught the small debris! The capacitor still looks to be intact except for leakage along the top edge. Interestingly and as adventurous as I am, I turned the motor on again only to find it still functions... However, the capacitor gets hot and produces the proverbial "smoke test" in seconds!
Pictured is the original and replacement capacitors for your review, but I think the parameters are very similar!
Any direction/suggestions welcome... So sorry to hear about the exploded capacitor. That is caused by one thing - the capacitor was not disconnected from the circuit after the motor started. Thankfully it didn't burn the motor winding. That leads to a problem with the centrifugal switch, or the wiring between the winding, capacitor, and centrifugal switch. I sure hope that compressor is good. I have never seen a Mills branded compressor. It looks almost exactly like a Kelvinator. Will have to go back and look at the pictures. If you end up needing assistance with the belt drive compressor, please don't hesitate to reach out to me. I'm one of the last guys out there with a current working experience base with them. |
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Post by beschen on Mar 19, 2023 15:28:14 GMT
I'll have to get back inside and determine if it's a mechanical issue since a wiring issue will be more challenging to correct... The actual centrifugal switch is mounted in the rear housing and the actuator is mounted on the tail end of the rotor. Based on what has occurred, it's safe to say the contacts are good because the motor rotates; I just need to evaluate why the centrifugal actuator is not pressing the switch plate during increased RPM thus opening the switch and removing the capacitor from the circuit... I thought everything seemed in order and moved freely upon my initial investigation... I'll have to revisit the internals and get back to you...
I cannot remove the compressor until the system is evacuated, which could very well be empty already, and disconnect lines to separate the evaporator and compressor... This is something I cannot perform as I do not have the equipment. It appears most connections are compression type which is good for servicing/removing components; however, I believe these types of connectors are prone to leaks over the years which may the case for my system... I'll have to visit the refrigeration shop working on a Blissfield unit for me and ask them to evacuate the system so I can removed the complete refrigeration system... Once I can do that I can definitely get better photos of system components! I'll also need to obtain threaded caps/plugs to keep the elements out of the system while restoration continues!
Lastly, I would love to bring the complete system to you to get it functional and cooling properly; unfortunately, shipping would be out of question and I do not have any scheduled travel plans in your direction... At least not yet! I have something brewing in Louisiana that could bring by your shop...
Thank you for your time & input!
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Post by beschen on Mar 19, 2023 22:34:24 GMT
Back with positive results!
Motor now functions fine as seen in photo; it's running at 3.49 amps, tag reads 3.6 amps. I'm even utilizing the newly over-heated capacitor; I have another spare just in case!
The lesson is to be sure things are put back together correctly!
Pictured, I am pointing to the two springs, one on either side, on the centrifugal actuator. These were slightly out of position and not in the bakelite coupler correctly.
In the third photo, I am pointing to what I believe is some sort of thermal overload protection... I checked for continuity and figured it was some type of protection as this switch was closed. Any idea what this may be...?
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Post by turbokinetic on Mar 20, 2023 1:13:29 GMT
I'll have to get back inside and determine if it's a mechanical issue since a wiring issue will be more challenging to correct... The actual centrifugal switch is mounted in the rear housing and the actuator is mounted on the tail end of the rotor. Based on what has occurred, it's safe to say the contacts are good because the motor rotates; I just need to evaluate why the centrifugal actuator is not pressing the switch plate during increased RPM thus opening the switch and removing the capacitor from the circuit... I thought everything seemed in order and moved freely upon my initial investigation... I'll have to revisit the internals and get back to you...
I cannot remove the compressor until the system is evacuated, which could very well be empty already, and disconnect lines to separate the evaporator and compressor... This is something I cannot perform as I do not have the equipment. It appears most connections are compression type which is good for servicing/removing components; however, I believe these types of connectors are prone to leaks over the years which may the case for my system... I'll have to visit the refrigeration shop working on a Blissfield unit for me and ask them to evacuate the system so I can removed the complete refrigeration system... Once I can do that I can definitely get better photos of system components! I'll also need to obtain threaded caps/plugs to keep the elements out of the system while restoration continues!
Lastly, I would love to bring the complete system to you to get it functional and cooling properly; unfortunately, shipping would be out of question and I do not have any scheduled travel plans in your direction... At least not yet! I have something brewing in Louisiana that could bring by your shop... Thank you for your time & input!
I'm very happy to help! Love seeing these old systems get fixed up. They won't be compression fittings. They will be SAE flare fittings. When you go back together with them, be sure to install flare gaskets such as Flareseal https://flareseal.com/I live by these on the old systems. You can get reliability similar to true hermetic soldered connections with them. If I were you, I would try loosening a line and see if any pressure remains. I expect it will not. You can get SAE flare caps and plugs at many shops including Lowe's and Ace Hardware. As for the system you have, it was a Freon-12 system so there is no danger to you for opening the lines. You should simply try to crack one open and see if there is pressure before taking it anywhere and having them charge you money to tell you that information. If there is pressure, close it back up and take it to be recovered. Back with positive results! Motor now functions fine as seen in photo; it's running at 3.49 amps, tag reads 3.6 amps. I'm even utilizing the newly over-heated capacitor; I have another spare just in case! The lesson is to be sure things are put back together correctly!
Pictured, I am pointing to the two springs, one on either side, on the centrifugal actuator. These were slightly out of position and not in the bakelite coupler correctly.
In the third photo, I am pointing to what I believe is some sort of thermal overload protection... I checked for continuity and figured it was some type of protection as this switch was closed. Any idea what this may be...? That is great that the motor started behaving! It's sometimes tricky to get things back together. I prefer to use the Kill-A-Watt meter to verify that the current is within spec after working on a motor. That can allow me to power it off before anything burns or explodes if there is excess current. It's funny that the blown capacitor still works. I expect it will work until the electrolyte fluid dries up inside, and loses its conductivity. As for the item in the third photo, that is likely a thermal overload breaker but it is an early design one I haven't seen before. Thanks for taking the time to share your progress here! Sincerely, David |
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Post by beschen on May 5, 2023 2:17:07 GMT
Hello again!
Wanted to update you with both progress and more questions...
I'm having some issues with video at the moment but I included a link to a video. I installed the motor I repaired with the belt present in this machine even though it's in rough shape. You may even see the electric motor "wiggling" somewhat during this test. I let the system run for approx. 25 minutes and to my surprise, the system began to cool down within 4 minutes eventually to the point of getting frost on the outer coils ! ! ! This system probably hasn't ran in decades!
OK, moving forward I would like to know any precautions I need to take since a refrigeration tech is coming to my shop next week to evacuate the system of freon 12... Everything is getting removed and restored, then I'll install everything back into the soda machine so the tech can come back, recharge the system and check everything for proper operation... Are there special caps/fittings I can thread into connectors to keep things sealed as much as possible...?
Any recommendations on changing the oil...? My current refrigeration guy said it may be best to leave the current oil in place... My thoughts are: how do I know for sure how much is supposed to be present and/or how much could be missing...? On one lower side of the compressor there appears to be a threaded fill/drain port, but since it's oriented upwards, draining would require tilting the compressor quite a bit to remove all the oil.
Once I have the evaporator system disconnected from the condensing unit or compressor, I'll post photos of the unit for direction on what parts are what and, more importantly, what should be replaced...
As always, I Thank you for your time, expertise and direction!
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