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Post by k5carrillo on Sept 15, 2013 22:15:54 GMT
OK, so my square top FEA-2-B16 has been working great, except for the fan issue I previously reported. I have been using a desk fan as a temporary measure until I can deal with the fan replacement.
Last night as we were heading to bed, we realized the fridge was beginning to defrost. Adjusted the thermostat and the compressor would not start. Emptied the fridge and unplugged it.
In the morning I plugged it in and the compressor did start but sounded different and it only ran for a few seconds. I thought I heard the relay click and it shut off.
The relay is an R type. I am not sure how to properly troubleshoot it and/or the thermostat.
I have been reading through the Scotch Yoke manual, but any words of assistance would be greatly appreciated.
Thanks.
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Post by coldspaces on Sept 15, 2013 22:26:00 GMT
You most likely heard the overload trip when it shut off. I would guess the relay points may be burnt up and either not making connection to bring in the start winding or welded together and keep the start winding on too long.
Assuming the windings are still good you need to have an amp meter on the start winding and see if it draws any amps. If not points are not making connection in the relay. If it does draw power and keeps drawing it even after the compressor is up to speed the points are welded together.
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Post by cablehack on Sept 15, 2013 23:47:15 GMT
Those units use the one knob control. I'm not sure if it's the same as some of the prewar Flatops, but anyway, it doesn't incorporate overload protection - just a thermostat. The R type relay has built in overload protection. So, if you suspect the thermostat is faulty you can simply bridge out the connections - if it starts and runs and sounds normal, then that's where the fault is. But, I'm inclined to agree with Coldspaces and suspect the relay. If that's faulty, the compressor will sound different and the overload will trip. If you can identify the start, run, and common wires to the compressor, you can actually confirm a faulty relay by running the motor without. To do this, apply 120V to the run and common wires and briefly touch the start wire to the run for a couple of seconds and no longer (or you'll burn out the motor). Note that that's only a test - there is no overload protection running the motor that way.
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Post by k5carrillo on Sept 16, 2013 16:03:11 GMT
I will try a test run tonight if possible. As I do not have an ammeter, I did disconnect the relay and thermostat and take some resistance readings. I have listed my readings on the attached diagram. I realize this diagram is not for my machine, but the components, wire colors, and connection points agree with my machine. As I reported earlier, my fan has been dead. I did add a desk fan......but never disconnected the dead fan. It never felt hot, nor did its wire, but I know that was stupid. I hope that I did not fry something by leaving it in the circuit. Anyway, the thermostat does go OPEN in the OFF position, and is 0 ohms anywhere else. Nothing shows as dead shorted, but I have no idea if my readings are normal. I will let you know how the test goes tonight. Until then.......any thoughts? SY102 with comments.pdf (346.61 KB)
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Post by coldspaces on Sept 16, 2013 17:05:26 GMT
Compressor ohms look good, had almost the same readings on the compressor in my 48 GE. Not sure what is normal for the fan and why it has a 3rd wire. Be careful running with no overload and no amp meter to know what is happening. Unless the compressor stuck mechanically I am betting it will start right up when you do your test.
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Post by cablehack on Sept 16, 2013 23:09:10 GMT
Knowing the FEA has a fan, I suspected the wiring diagram would be the same as one of the fan equipped Flatops. The reason for the fan having three wires is because it's a two phase induction motor. The compressor motor start winding generates the second phase to power the fan. Clever idea that eliminates the need for a separate relay for the fan motor.
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Post by k5carrillo on Sept 16, 2013 23:19:41 GMT
Just curious, why the cautions about always having the R relay vertical when powering the machine?
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Post by cablehack on Sept 16, 2013 23:23:21 GMT
The relay position is important in all machines because of the weight of the relay armature. If, for example, you mount an R relay horizontally, the weight will cause the contact to sag slightly and thus affect the current sensitivity.
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Post by k5carrillo on Sept 17, 2013 4:42:03 GMT
OK...so before I attempted my running test without the relay I decided to check everything again. When I started I had everything disconnected and put an ohmmeter across the thermostat and power cord prong. I was able to cycle between OPEN and SHORT by turning the thermostat knob. Then I did the same thing plugged in with my meter on volts and could see 0 or 120 volts as I turned the knob. So at least the thermostat was doing its thing.
Then I hooked up the compressor and power leads to the relay, clipped my voltmeter leads to posts 2 and 3, plugged into power and turned the thermostat knob. Nothing. No sound, no voltage reading.
Then I took the relay back out, I clipped the white power wire to the black motor common wire. I also clipped the white thermostat wire to the green run coil wire. With the thermostat in OFF, I plugged it in and temporarily held the white starting coil wire to the green run coil wire and had my son turn the thermostat knob. Nothing. No sound, no voltage reading.
So I took it all apart again and now I only see an OPEN across the thermostat, no matter where the knob is set. It would certainly appear that the thermostat is intermittent, at best, perhaps completely failed in the OPEN position.
Tomorrow I plan to make a better hook-up arrangement with a remote switch and try running the motor with no thermostat or relay.
Until then, what words of advice/encouragement can you give me about replacing a thermostat? I see that Antique Appliance sells a RANCO unit for $100. Are these any good? Hard to install? Should I look at a different part/vendor.
Again, I appreciate all the help.
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Post by coldspaces on Sept 17, 2013 12:43:31 GMT
Could just be that it is your cold control. I would hook the relay back up and jumper the cold control wires and see if it starts and runs correctly. If not you may also have a relay problem.
Intermittent connection in the cold control could have cause the relay points to chatter and burn.
I have a Ranco appliance control cross reference from 1979 that list some older #s and their recommended replacements. Probably won't go back far enough for yours but it is worth a shot, I know it goes back to at least 1951 on the International Harvester refrigerators. If you post the part # of your old control I will check and see.
Otherwise some pics of it and if someone has the specs it works at and will list them will help match something up you know should work correctly.
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Post by coldspaces on Sept 17, 2013 17:50:14 GMT
Looks like page 54 in the 37 -42 manual has the specs for the single knob controls, if they mach your machine I am not sure of.
Is your machine so2 or R-12. Manual says the R-12 controls were 3-6 degrees warmer.
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Post by k5carrillo on Sept 17, 2013 19:38:32 GMT
My machine is an R-12 unit.
The model number off of my thermostat is M1A272. I googled it and it crosses to a MARS 26244 or Robert Shaw 3030-501.
What RANCO part number do you get?
Whichever one I end up with.....how do I deal with the 42 inch capillary tube? I have never installed one of these.
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Post by coldspaces on Sept 17, 2013 22:26:28 GMT
I will see what I can find for a Ranco #. The extra capillary just has to coil up and hide some were. Here is mine in the 48 Spacemaker.
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Post by k5carrillo on Sept 17, 2013 23:18:45 GMT
So does the extra coiled up portion need to be inside the fridge or can it be on top with the thermostat itself? I noticed that the end of my capillary tube is currently clamped to the evaporator, but I was not sure what to do about the rest of the coil.
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Post by coldspaces on Sept 17, 2013 23:45:07 GMT
So does the extra coiled up portion need to be inside the fridge or can it be on top with the thermostat itself? I noticed that the end of my capillary tube is currently clamped to the evaporator, but I was not sure what to do about the rest of the coil. Souldnt matter as long as the correct amount of the end is clamped to the evap.(aprox. 6" on most). The exception would be if the control body and extra tube are mounted in a place colder than the end of the tube clamped to the evap. Can aLso be coiled much smaller than I have mine as long as it doesn't kink
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