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Post by turbokinetic on Jan 29, 2022 4:16:04 GMT
So I ordered a bristle key. What kind of oil (PAO mineral oil?) and where can I get it in small quantities so I can test for NCG’s? I haven’t been to the house to check the relay yet. I’m going to check for 1000 ohms at the power cord (although it's a new 12W heater), take pictures, and check and release any NCG’s. After I eliminate the room temperature NCG's then I'll start heating the oil for 24+ hours and try a system start. Correct? I just watched CableHacks NCG bleeding video. So sewing machine oil ... Hi Mike. Glad you're moving forward with it. You won't need any specific oil and 3-in-1 oil or automotive non-detergent engine oil will work. This is because these used mineral oil and any small volume of mineral-type oil which goes into the system won't hurt it. Whatever you do, don't use any polyolester or polyethylene glycol oils. These will damage the machine. They need mineral oil; or you can use alkylbenzene oil which is just a synthetic mineral oil.
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Post by mike75 on Feb 3, 2022 6:37:32 GMT
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Post by cablehack on Feb 3, 2022 12:15:43 GMT
The attempted startup is typical of a stalled CA. Hopefully, once you've got the Bristol key, you can see if it's NCG causing the stalled condition. 1.44k ohms will dissipate 10W at 120V, which I note is the power consumption you have previously measured. The relay arcing is quite normal. The contacts are switching an inductive load; i.e. the start winding, and the fact that the motor can't rotate also means it's drawing more current than normal. On a positive note, it does show the start winding is in circuit. The plug pulls off with a slight twist.
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Post by turbokinetic on Feb 3, 2022 15:25:45 GMT
Hey there Mike! That relay looks to be in almost new condition. There is no sign of overheating of the coil (it is still nice and amber color; not blackened). That bodes well for the compressor motor. The flash from the contacts is normal. It makes and sparks once as it makes contact, then it has no sparking during the duration of the start attempt. That indicates it maintained a solid connection during the start attempt. As Cablehack said, the plug rotates to one direction or the other (it's marked) and pulls down. If people have tried to force it off without twisting, in the past, it's sometimes very difficult to get it off without breaking it. Hopefully that 10W heater is adequate. I have my doubts that it will be enough heat to help get the compressor free, if it's stuck. Once the machine is running, it will definitely be better than nothing. Will be interested to hear how it goes once you are able to purge off the overpressure, and then do a series of factory manual procedure periodic purgings while it's running. Sincerely, David
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Post by cablehack on Feb 4, 2022 0:13:35 GMT
Hopefully that 10W heater is adequate. I have my doubts that it will be enough heat to help get the compressor free, if it's stuck. Once the machine is running, it will definitely be better than nothing. I was a bit concerned about that too. I'm sure I've seen somewhere that the resistance of the originals was meant to be closer to 1000 ohms (14.4W @ 120V, or to be pedantic, 12.1W for the 110V the CA machines were designed for), since that's the resistance value I made for my CA-2 heater. My original CA-1 heater measures 950 ohms.
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Post by mike75 on Feb 15, 2022 22:50:11 GMT
Hey Dave, There were no NCG's released. The oil level dropped when I slowly loosened the plug. So it's plugged it to run the 10W heater. I'll try the start again in a week. So should I purchase a different heater? 15W, 20W, 25W, 30W ... larger ? I was going to try to put a heating pad on top and run a hair dryer over the cooling fins. What do you think? If it wasn't so heavy and in the basement I would try the "let's see how cold I can get it outside"
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Post by turbokinetic on Feb 16, 2022 13:44:59 GMT
Hey Dave, There were no NCG's released. The oil level dropped when I slowly loosened the plug. So it's plugged it to run the 10W heater. I'll try the start again in a week. So should I purchase a different heater? 15W, 20W, 25W, 30W ... larger ? I was going to try to put a heating pad on top and run a hair dryer over the cooling fins. What do you think? If it wasn't so heavy and in the basement I would try the "let's see how cold I can get it outside" Hi Mike. That is a good sign that it has no severe NCG overpressure. That should mean it's safe to start up; however once it's fully warmed up and running you should check one more time. I would say that you should confirm for sure, 100% that the winding ressitances and resistance to ground are both correct next. Once you confirm that there are no open circuits or short circuits, it might be time to try boosting the motor with higher voltage, after letting the 10W heater work overnight. The heat needs to be very specifically applied to the oil sump, because that is where the compressor mechanism is located and therefore is where you want to drive away refrigerant from. Applying heat to the condenser fins will be counter-productive because you want the condenser to be the coolest place, so the refrigerant will migrate from the oil to the condenser. Heating the condenser will undo what the oil heater has done.
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Post by mike75 on Feb 17, 2022 1:22:59 GMT
Thanks Dave ... Please help me understand the steps to validating "winding resistances and resistance to ground are both correct"
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Post by turbokinetic on Feb 17, 2022 1:25:45 GMT
Thanks Dave ... Please help me understand the steps to validating "winding resistances and resistance to ground are both correct" Before applying higher voltages to it, it's wise to be sure the motor isn't electrically failed. With the relay cover removed, you can measure the resistance of the start and run winding; plus measure from the motor circuits to ground. The ground resistance should be in the high meg-ohm range. The run should be 2 to 4 ohms, and the start maybe 10 ohms. This is going from memory though.
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Post by mike75 on Feb 17, 2022 2:18:37 GMT
So I'm measuring the resistance from between Red (run) and Black (2-4 ohms), then WHITE (start) and Black (10 ohms)? Then RED, White, Black each to ground (high mega ohms each)... correct? It's going to be a week (Feb 23rd?) before I'm back to the refrigerator - the heater is running. Thanks to the "someone" that created the relay diagram - I don't remember where I got it while researching everything. I updated it with info I've been collecting. Any corrections, let me know.
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Post by cablehack on Feb 17, 2022 4:04:13 GMT
Thanks to the "someone" that created the relay diagram - I don't remember where I got it while researching everything. That was drawn out by yours truly, way back in the days before we had any proper service info on the CA's. It's just on 10 years ago I got my CA-2, and there was nothing except a GE film strip with some basic CA repairs shown. Here's the original posting of the diagram www.flickr.com/photos/13469158@N05/7672875200/in/album-72157633054818403/Your CAD drawn diagram looks good! And your resistance readings sound right.
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Post by mike75 on Feb 24, 2022 5:42:47 GMT
So still didn't start ...
Measured resistances while unplugged:
Red to Black was 1.454 K ohms
White to Black was also 1.475 K ohms
Red to White was 23.0 ohms
Heater was 1.450 K ohms
All resistances to ground (screw on relay housing) didn't register at 40M on meter
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Post by turbokinetic on Feb 24, 2022 6:03:13 GMT
So still didn't start ... Measured resistances while unplugged: Red to Black was 1.454 K ohms White to Black was also 1.475 K ohms Red to White was 23.0 ohms Heater was 1.450 K ohms All resistances to ground (screw on relay housing) didn't register at 40M on meter Good that you were able to make measurements, and they tell where to look next. All measurements involving the black wire are high-resistance. The thermostat control is in the black wire, so it makes me think that the thermostat may be off or defective and not making contact. If you place a jumper wire into the thermostat connector, to bypass it, maybe the motor resistances will look better.
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Post by mike75 on Feb 24, 2022 17:09:13 GMT
Finally got the plug removed from the thermostat (on/off). Very tight spot to twist and pull. I put a jumper wire in the thermostat plug and retested the resistances
Measured resistances while unplugged:
Red to Black was 3.5 ohms
White to Black was also 20 ohms
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Post by turbokinetic on Feb 24, 2022 17:47:44 GMT
Finally got the plug removed from the thermostat (on/off). Very tight spot to twist and pull. I put a jumper wire in the thermostat plug and retested the resistances Measured resistances while unplugged: Red to Black was 3.5 ohms White to Black was also 20 ohms That sounds like perfect resistance measurements. Sometimes the contacts in the control will get an oxide layer which shows as high resistance; however once actual mains voltage is applied, the resistance breaks down and current flows normally. So nothing to worry about at this time. I would hook the thermostat back up normally, because it contains the overload circuit breaker. Then, give it a few of shots of 240V and see if it breaks free. You will need to build a test setup to do this safely. It will need to connect to a "real" 240V outlet, such as a 240V dryer outlet or 240V window A/C outlet. It won't work with a step-up transformer. The test setup will need a plug which connects to the 240V power outlet. It will need a switch capable of making and breaking at least 30A; and finally it will need an outlet to plug the fridge into. To prepare the fridge for this, make sure the heater has been on overnight at normal 120V. When the time comes to make the boost attempts, unplug the fridge from the standard 120V outlet. To prepare for the boost attempt, take these steps: 1 - Warm overnight with crankcase heater as usual. 2 - Unplug fridge from normal 120V outlet. 3 - Turn fridge thermostat ON 4 - Turn switch for boost outlet box OFF. 5 - Connect boost cord to 240V and plug fridge into boost outlet. This prepares you for boosting. To carry out the actual boost procedure, take these steps. This is for a totally stuck machine: 1 - Turn the boost outlet on for about 1/2 second and then turn it back off. 2 - During the time the power was on, listen carefully for the compressor to run. 3 - If there was no start, wait about 5 seconds. 4 - Repeat the 1/2 second bursts, with a 5 second rest. Repeat up to 10 times. 5 - If the machine has not yet started, wait for a 5 minute cooldown time. If the machine runs during the 1/2 second boosts, return the cord to the standard 120V outlet and see if it will run on its own. If so, then let it run and see how it does. If it won't start, proceed as follows. This is for a machine which starts on 240V but not on 120V: 1 - Reconnect to the boost outlet as instructed above. 2 - Turn the boost outlet on for about 3 seconds. Machine should run. 3 - Allow a 1 minute cooldown. 4 - Repeat the 3 second run / 1 minute cooldown for at least 3 times. 5 - Return the machine's power cord to the 120V outlet and see if it will run on its own. 6 - If it will not run on its own, allow a 5 minute cooldown period and then repeat. The keys to remember here is that the thermostat and overload breaker and start-relay are in the circuit. The start-relay should close and stay closed at all times when the machine is receiving 240V, even if it starts. This is due to the very high current which flows from the increased voltage. Listen for startup, don't rely on watching the relay movement to determine if it started or not. The overload breaker should not trip during the boosting. If the overload trips, there is something wrong with the motor, or the boosting has been done too aggressively for too long. Hopefully this helps!
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