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Post by davido on Feb 17, 2020 22:01:07 GMT
So...the DR decided it didn't want to cool correctly. I did manage to get down to 5° two days in a row. the third day it wasn't having it. So...per some advice on here.. I pulled the unit off and she's upside down. .not sure how long to leave it... but I can hear bubbles of SO2/OIL draining back to the dome...I'm guessing when the sounds stop....it's time to turn it back up. Can anybody with experience tell me if this has to be done several times?...or usually just once? I'm posting pics of the unit and cabinet. All wood was in perfect condition! Can't believe that. I will replace all foam. I scraped the old out. It was in bad shape. Thanks for any comments and help. DR pics
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Post by elec573 on Feb 18, 2020 2:15:05 GMT
I’m sorry to hear about your dr I thought it was doing ok but apparently not . As far as tipping it up side down I’d consider that a last resort. Everything in the bottom of the sump is displaced and now flowing around, the system. But if this was your last option it could not hurt . I have come late or maybe caught you on another thread . But Turbo had suggested that drs can have non condensed gases as well (and his reasoning is sound ) have you tried purging them ? It’s a very nice looking fridge hopefully you can get it back to normal.
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Post by Travis on Feb 18, 2020 2:30:09 GMT
so2 units don’t have NCGs. I’ve never needed or wanted to flip a DR upside down. In fact, it’s not desirable to fill the condenser with oil.
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Post by davido on Feb 18, 2020 4:16:11 GMT
Travis...when I did flip it...I could hear alot of fluid in the freezer coils....and then I could hear it bubbling back into the dome. At this point.. I guess It couldn't hurt to try???
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Post by elec573 on Feb 18, 2020 4:35:53 GMT
It’s your fridge try what you think might work. Are you any worse off then when you started ? Drs are finicky but they are the first.
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Post by birkie on Feb 18, 2020 4:52:53 GMT
The only top I've had upside down was brought to my car in a wheelbarrow that way. Once it's upright again, you need to make sure the liquids get where they should be: oil in the sump, liquid refrigerant in the evaporator.
Before running it again, I'd - Run the heater at least a day (machine plugged in, off), until it stops making soft bubbling noises from refrigerant boiling near the heater. - Once that's done, fill a ziplock bag with boiling water, and put it in the evaporator. Try to get it to stay in. After a couple minutes, you should hear sort of a liquid rushing sound. This is refrigerant and oil forcing its way up from the evaporator into the dome. Keep the hot bag in the evaporator until the noises die down. Ideally, this will have forced most of the oil trapped in the evaporator back into the sump. - Run the heater again until no boiling can be heard.
Then fire it up and see how it goes!
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Post by davido on Feb 18, 2020 4:57:39 GMT
Thanks everyone! I will try everything I've been told.
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Post by Travis on Feb 18, 2020 11:10:05 GMT
You’re only worse off if it fails as you’re experimenting with it. Follow Birkie on this one.
My original concern about someone mentioning NCGs in a DR was that future readers would not read that was with 152a not so2. I was also told by Gill to avoid flipping the units over.
I’m certainly not wanting to be a downer, but want you to not spin your wheels while working on this. Repeated pull down cycles are hard on these machines.
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Post by Travis on Feb 18, 2020 11:14:22 GMT
What does the frost pattern look like? You got it to 5 degrees. What was the cabinet temp? What was the ambient room temp? How is the door gasket?
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Post by davido on Feb 18, 2020 13:12:02 GMT
Travis...when It worked and got to 5° the 2 days...It seemed to work great....the enamel freezer was froze evenly...the temp outside was in the 60s. I only read temp in freezer. The door seals are original cloth rope type....however...the seal around the top was crumbling...that could have been a reason it didn't not pull down any further.....but it only got that cold 2 days...the 3rd day only got to 11°...and worse the 4th day....I will flip it back today and let things settle down and let the heater run tonight...then tomorrow see if any change.
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Post by coldspaces on Feb 18, 2020 14:05:07 GMT
I told him he could turn it upside down to make the float open. I have done it in the past to get all the so2 out. I didn't think about the fact everyone thinks it will stir up everything in the bottom of the sump. Sometimes its the easiest way to open the float. The service manual does tell us to turn it upside down for some procedures such as trying to clear a blocked float.
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Post by turbokinetic on Feb 18, 2020 14:14:59 GMT
Hi David. I'm sorry that the DR has not worked as well as it should. There are a few things I would recommend you get out of the way first, as far as testing goes.
First; are you 100% sure the heater is working? It must be working all the time, whether or not the compressor runs. It is possible to connect it incorrectly where it is bypassed while the compressor is running. The heater needs to operate, especially while the compressor runs. Several of us have found that the older DR's work better with higher than original heater wattages. This may be due to carbon buildup keeping the heat from reaching the oil, or possibly carbon buildup in the condenser tubing limiting the heat transfer from the refrigerant gas. But it has been a fact for several units. Regardless, the heater is a very important part of the system.
Next, be sure the motor isn't already on its way out. Use a digital meter on the Ohms scale; and measure the resistance between the motor input wires and the frame of the cooling unit. You will be measuring resistance between the motor winding and ground. This should be in the "several mega-ohms" range. If it is not in this range, then the motor winding insulation is failing and you are likely seeing the effects of this in the poor performance.
If you get a bad reading, it pays to isolate the wires from the control and ensure the ground fault is really in the motor and not the wiring.
The reason I mention this is because of your issue with the start-relay armature not wanting to drop back down. If the motor is damaged and is drawing extra current, then it will lead to this problem, and then progress to worse problems over a short period of time.
Also you need a Kill-A-Watt meter. If you aren't familiar with these, it is a plug in meter that allows you to measure amps, watts, and other motor load parameters. With this info, one can determine what sort of mechanical load the motor is seeing from the compressor, as well as telling if the motor is drawing excess amps due to winding damage.
There are only two ways a SO2 machine can have noncondensible gases. One of them is a low-side leak while running. That would turn to an external refrigerant leak once the unit stopped. You would likely smell it, or possibly the charge would be gone by now. There would also be oil leaking somewhere. The other way is by chemical reactions due to the motor burning out. The cotton (cellulose) insulation releases water at very high temperatures through a process called pyrolysis. It is debatable how hot it must get for this to happen, but we all agree that a bad overload, bad start-relay, and extended running without cooling due to a float problem can damage the winding. Once the water is released into the SO2, the result is set of chemical reactions which end up producing hydrogen. This is driven by the heat from the damaged motor. The bottom line is, SO2 machines never develop NCG's as a result of normal operation. This is a factor with the CA (methyl formate) units only.
A great resource is the GE factory manuals which have been scanned and shared here. They have cutaway drawings of the compressors, as well as troubleshooting guides for different scenarios such as yours.
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Post by davido on Feb 18, 2020 14:34:49 GMT
Thank you Turbo. I only have a multi-meter right now...I'll have to acquire a wattmeter. I replaced the heater when I first got it...and can always hear it sizzling with ear to the dome. The replacement was a 15W cartridge heater hooked up exactly the way it was when I pulled the old one out.
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Post by davido on Feb 18, 2020 14:37:40 GMT
When you say a higher wattage cartridge.....should I replace the 15W cartridge with say....a 20W?
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Post by Travis on Feb 18, 2020 14:38:58 GMT
Thanks for the clarification. I would just keep it plugged in so the heater is on while you’re troubleshooting.
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