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Post by cr4west on Jul 25, 2021 17:22:09 GMT
Finally got around to looking at a 3 cu ft CF flat top the wife brought home from an auction. The tag says it uses Dichlorotetrafluoroethane R114. The rubber insulation on the wiring at the bottom of the unit was completely gone. Restored the wiring and verified the operation of the thermostat and power switch. Checked the compressor windings were not grounded out to the motor housing and found the resistance of the start coil 8.2 ohms and run coil 12.3 ohms. It appears to have a type R start relay. Unable to to get the compressor to run. Using the brief 220 volt test across both coils it will only emit a loud hum. The manual also talked about giving the compressor a hit or knock to loosen it but no detail of where. Does anyone have an idea on how to free up this compressor?
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Post by cablehack on Jul 26, 2021 0:41:27 GMT
The tag says it uses Dichlorotetrafluoroethane R114. R114 in any GE product would be very unusual. GE only ever used S02, MF, and R12. R114 was a Frigidaire refrigerant.
Aside from that, one test is to make sure the start relay is actually working. You can try manually starting the compressor. Disconnect the compressor form the rest of the wiring. Connect 120V to the common and run terminals, and then momentarily touch 120V onto the start terminal for a couple of seconds. It's important to do this test as quickly as possible (within about 10 seconds), since the run winding will be drawing a lot of current until the motor starts, and there will be nothing to protect it from burn out.
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Post by ckfan on Jul 26, 2021 10:59:55 GMT
Yeah, if it’s using 114 it has to be a Frigidaire. I don’t think GE even made a 3 cu ft flat top. If someone put a type R relay on it in the past, that is an incorrect relay because it is meant for a larger horsepower compressor.
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Post by cr4west on Jul 26, 2021 14:34:54 GMT
My mistake, it is a Frigidaire by General Motors. I will try the test you suggested. I have included a couple pictures of it. Thanks for the quick response! |
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Post by turbokinetic on Jul 26, 2021 14:41:52 GMT
My mistake, it is a Frigidaire by General Motors. I will try the test you suggested. I have included a couple pictures of it. Thanks for the quick response! Very neat little Frigidaire! That is indeed an R114 Meter-Miser. That's probably the original first-design 1/20 HP Meter-Miser. These can get stuck as can any compressor. These very early ones like this had some design concerns and were more likely than others to have issues. Here's a video where I check out one of them and recharge it. You may get some ideas on electrical tests as well. The start-relay on these early ones is very complex and can mislead easily. https://youtu.be/ZbGMNDGXAQo |
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Post by ckfan on Jul 27, 2021 1:38:59 GMT
I see from the tag that it is one of the later 1/12 HP compressors so that is good. The 1/20 HP ones were said to run all day long on a hot day with normal use and ice making. Just like a modern fridge really!
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Post by turbokinetic on Jul 27, 2021 11:25:13 GMT
I see from the tag that it is one of the later 1/12 HP compressors so that is good. The 1/20 HP ones were said to run all day long on a hot day with normal use and ice making. Just like a modern fridge really! That's good! I didn't look closely enough. The little 1/20 unit I shared does just what you mention and runs constantly when it's hot in the shop. It also has some other less than endearing traits. For one, if the power glitches just "wrong" the compressor will begin to slow down but will then re-start in the reverse direction. Once running backwards it will make a different noise and will not cool. Obviously the 1/20 HP was an early and excessive attempt at energy saving! |
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Post by ckfan on Jul 27, 2021 23:00:26 GMT
Holy cow! It will slow down and run backwards?! How?!?! That’s insane. And I’m assuming it would run that way forever until you restarted it? That’s insane.
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Post by turbokinetic on Jul 28, 2021 12:46:32 GMT
Holy cow! It will slow down and run backwards?! How?!?! That’s insane. And I’m assuming it would run that way forever until you restarted it? That’s insane. It's insane and probably why so few of these still are working. When it does it; it seems like the thermostat or overload will "glitch" and interrupt power for a fraction of a second. Then the compressor sound will change to a more "sputtery" sound. It will pull slightly more power under these conditions but not alarmingly much. During this time, the compressor will get very hot but the lines coming out of it will not be hot, indicating no pumping action. Stopping and immediately re-starting will result in the sound returning to normal and the system cooling again. I have a new overload on order for it. These have such a small rated current demand that the usual RO81 overload wouldn't protect it. I had to special order an RO82 which has a maximum running current of 1.66 amps. That should catch the 2.0 amps it draws when running backwards. The normal running current is only 1.5 amps. The factory overload will not trip when it runs backwards. |
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Post by ckfan on Jul 28, 2021 19:00:58 GMT
That is beyond stupid. Glad you caught it and are going to protect it with a very sensitive overload.
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Post by turbokinetic on Jul 28, 2021 19:18:23 GMT
That is beyond stupid. Glad you caught it and are going to protect it with a very sensitive overload. Yep. I would rather see it trip spuriously every now and then; as opposed to getting ruined. It's a very unique piece of history. |
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