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Post by turbokinetic on May 24, 2023 21:08:08 GMT
Sounds good. Yeah those nameplates state the maximum test pressure for the low side and high side individually; as well as the maximum charge weight for any system using that compressor. It is not an exact charge amount for the system and must be charged by frost line (area of the evaporator actually freezing.) I would definitely recommend not trying to re-use this charge after recovery unless you are using a recovery-recycling machine which will ensure the purity is good. It should only take one can or so of refrigerant, so I would invest in new refrigerant so as to "play with a full deck of cards" so to speak. I do use recovery machines but typically on larger systems where I have just charged in a large volume of refrigerant of good quality, and have to remove it to make repairs. Old systems like this, particularly with a suspected moisture problem are probably best disposing of the old gas and starting over. That's what I figured, wasn't thinking right. I have no plans of reusing the old refrigerant though, I just wanted to safely contain it rather than just venting it into the atmosphere since I know r12 is the ozone killing stuff and I got a can of 152a air duster ready to go already. I started pumping it down with the vacuum pump, but I am going to have to pipe the pump exhaust out the window since the residual refrigerant it's pulling out of the system is stinking the place up since the fridge is located in a basement. I'm going to make an exhaust pipe then I'll let the system sit under a vacuum and bake for a while. That's good. You should have success once it's recharged! Odd that you have a bad smell in the system Normally R12 systems only have a light oily smell, like sewing machine oil. I guess if the system had overheated and had water for a long time, it could have sort of soured internally. I would change the oil it it were mine; if there is a bad odor.
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jackj
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Post by jackj on May 25, 2023 2:26:33 GMT
That's what I figured, wasn't thinking right. I have no plans of reusing the old refrigerant though, I just wanted to safely contain it rather than just venting it into the atmosphere since I know r12 is the ozone killing stuff and I got a can of 152a air duster ready to go already. I started pumping it down with the vacuum pump, but I am going to have to pipe the pump exhaust out the window since the residual refrigerant it's pulling out of the system is stinking the place up since the fridge is located in a basement. I'm going to make an exhaust pipe then I'll let the system sit under a vacuum and bake for a while. That's good. You should have success once it's recharged! Odd that you have a bad smell in the system Normally R12 systems only have a light oily smell, like sewing machine oil. I guess if the system had overheated and had water for a long time, it could have sort of soured internally. I would change the oil it it were mine; if there is a bad odor. I wouldn't say the oil smelled terrible, it was somewhat of a strong chemical smell and it didn't smell burnt or anything. But anyways, I went ahead and charged a can of r152a into the system and the results were a bit disappointing. I charged in about 3 oz increments and after finally charging the whole can, I have no cooling at all, but I can still hear refrigerant gurgling and flowing through the freezer evaporator. I also noticed that the pressure does not increase when the compressor is running, but there were a few times where the pressure did increase by about 10 psi. I'm starting to worry that the compressor may not be functioning properly due to the fact that it may not be pumping enough. Or perhaps I still need to add more refrigerant? Condenser coil did not get warm at all but I will say the suction line was the slightest bit cool at the point where it exits the cabinet to run back to the compressor. What do you think is going on? Please excuse my inexperience here, I have never worked on anything this old but I don't want to give up on this thing yet!
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Post by turbokinetic on May 25, 2023 10:22:12 GMT
That's good. You should have success once it's recharged! Odd that you have a bad smell in the system Normally R12 systems only have a light oily smell, like sewing machine oil. I guess if the system had overheated and had water for a long time, it could have sort of soured internally. I would change the oil it it were mine; if there is a bad odor. I wouldn't say the oil smelled terrible, it was somewhat of a strong chemical smell and it didn't smell burnt or anything. But anyways, I went ahead and charged a can of r152a into the system and the results were a bit disappointing. I charged in about 3 oz increments and after finally charging the whole can, I have no cooling at all, but I can still hear refrigerant gurgling and flowing through the freezer evaporator. I also noticed that the pressure does not increase when the compressor is running, but there were a few times where the pressure did increase by about 10 psi. I'm starting to worry that the compressor may not be functioning properly due to the fact that it may not be pumping enough. Or perhaps I still need to add more refrigerant? Condenser coil did not get warm at all but I will say the suction line was the slightest bit cool at the point where it exits the cabinet to run back to the compressor. What do you think is going on? Please excuse my inexperience here, I have never worked on anything this old but I don't want to give up on this thing yet! One question - how warm did you allow the compressor to get? These compressors are high-side housing designs and take quite a bit of time to warm up and start cooling. With one whole can of R152A in the system it should cool, but probably would be overcharged. Does the compressor sound normal, or is it making any clicking or other inconsistent sounds (longer than just for a moment at startup?)
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jackj
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Post by jackj on May 25, 2023 16:25:54 GMT
I wouldn't say the oil smelled terrible, it was somewhat of a strong chemical smell and it didn't smell burnt or anything. But anyways, I went ahead and charged a can of r152a into the system and the results were a bit disappointing. I charged in about 3 oz increments and after finally charging the whole can, I have no cooling at all, but I can still hear refrigerant gurgling and flowing through the freezer evaporator. I also noticed that the pressure does not increase when the compressor is running, but there were a few times where the pressure did increase by about 10 psi. I'm starting to worry that the compressor may not be functioning properly due to the fact that it may not be pumping enough. Or perhaps I still need to add more refrigerant? Condenser coil did not get warm at all but I will say the suction line was the slightest bit cool at the point where it exits the cabinet to run back to the compressor. What do you think is going on? Please excuse my inexperience here, I have never worked on anything this old but I don't want to give up on this thing yet! One question - how warm did you allow the compressor to get? These compressors are high-side housing designs and take quite a bit of time to warm up and start cooling. With one whole can of R152A in the system it should cool, but probably would be overcharged. Does the compressor sound normal, or is it making any clicking or other inconsistent sounds (longer than just for a moment at startup?) I let everything run for about 30 minutes last night. I do remember you mentioning in one of your videos that it does take a bit of time for these frigidaire compressors to start cooling properly (Compressor sounds normal to me no odd sounds). I let it run for an hour this morning and observed the same blockage problem I was experiencing at the very beginning of this thread. I hear refrigerant gas flowing in the freezer compartment but not the refrigerator section and after about 5 minutes the flow stops and the evaporator goes quiet while the compressor still sounds normal. I will say that at about the 45 minute mark I heard a rush of boiling refrigerant flow through the freezer evaporator that lasted only about 10 seconds. Perhaps there may be a blockage in the system other than the drier. Maybe the suction line screen? Compressor was pretty warm when I turned off power and was a bit uncomfortable to touch for more than 10 seconds. I'm really stumped right now! Here is a short video of what the compressor sounds like: imgur.com/a/92BG6vK
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Post by turbokinetic on May 25, 2023 17:05:38 GMT
One question - how warm did you allow the compressor to get? These compressors are high-side housing designs and take quite a bit of time to warm up and start cooling. With one whole can of R152A in the system it should cool, but probably would be overcharged. Does the compressor sound normal, or is it making any clicking or other inconsistent sounds (longer than just for a moment at startup?) I let everything run for about 30 minutes last night. I do remember you mentioning in one of your videos that it does take a bit of time for these frigidaire compressors to start cooling properly (Compressor sounds normal to me no odd sounds). I let it run for an hour this morning and observed the same blockage problem I was experiencing at the very beginning of this thread. I hear refrigerant gas flowing in the freezer compartment but not the refrigerator section and after about 5 minutes the flow stops and the evaporator goes quiet while the compressor still sounds normal. I will say that at about the 45 minute mark I heard a rush of boiling refrigerant flow through the freezer evaporator that lasted only about 10 seconds. Perhaps there may be a blockage in the system other than the drier. Maybe the suction line screen? Compressor was pretty warm when I turned off power and was a bit uncomfortable to touch for more than 10 seconds. I'm really stumped right now! Here is a short video of what the compressor sounds like: imgur.com/a/92BG6vKThat's very frustrating. It does sound like the moisture wasn't removed adequately. How exactly did you heat and evacuate the system? Needs to have all parts of the system heated to at least 120°F, with the compressor heated as hot as possible, ideally 150°F or so. I typically put a blanket (or several) over the cabinet and arrange a warm air heater to blow in under the blanket directly on the compressor. You may have to install a low-side port to properly diagnose this (to be honest.)
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jackj
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Post by jackj on May 25, 2023 18:11:09 GMT
I let everything run for about 30 minutes last night. I do remember you mentioning in one of your videos that it does take a bit of time for these frigidaire compressors to start cooling properly (Compressor sounds normal to me no odd sounds). I let it run for an hour this morning and observed the same blockage problem I was experiencing at the very beginning of this thread. I hear refrigerant gas flowing in the freezer compartment but not the refrigerator section and after about 5 minutes the flow stops and the evaporator goes quiet while the compressor still sounds normal. I will say that at about the 45 minute mark I heard a rush of boiling refrigerant flow through the freezer evaporator that lasted only about 10 seconds. Perhaps there may be a blockage in the system other than the drier. Maybe the suction line screen? Compressor was pretty warm when I turned off power and was a bit uncomfortable to touch for more than 10 seconds. I'm really stumped right now! Here is a short video of what the compressor sounds like: imgur.com/a/92BG6vKThat's very frustrating. It does sound like the moisture wasn't removed adequately. How exactly did you heat and evacuate the system? Needs to have all parts of the system heated to at least 120°F, with the compressor heated as hot as possible, ideally 150°F or so. I typically put a blanket (or several) over the cabinet and arrange a warm air heater to blow in under the blanket directly on the compressor. You may have to install a low-side port to properly diagnose this (to be honest.) Very frustrating indeed! I will admit I probably did rush the evacuation process a bit. I vacuumed the system for about 7 hours in total with only about 4 hours of actual heat directed only on the compressor with no blanket around the system. I was a bit afraid of wrapping a blanket around a heater and leaving it on overnight, but I will do it the right way now. My hermetic service kit did have a considerable leak in between one of the fittings which probably didn't help either so I fixed that the best I could. I'm venting out the system now and will then vacuum it down and bake it the correct way then start over. If this attempt fails then it's time to go back to the drawing board and install a low side port. Hopefully the second time is the charm!
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Post by turbokinetic on May 25, 2023 18:20:30 GMT
That's very frustrating. It does sound like the moisture wasn't removed adequately. How exactly did you heat and evacuate the system? Needs to have all parts of the system heated to at least 120°F, with the compressor heated as hot as possible, ideally 150°F or so. I typically put a blanket (or several) over the cabinet and arrange a warm air heater to blow in under the blanket directly on the compressor. You may have to install a low-side port to properly diagnose this (to be honest.) Very frustrating indeed! I will admit I probably did rush the evacuation process a bit. I vacuumed the system for about 7 hours in total with only about 4 hours of actual heat directed only on the compressor with no blanket around the system. I was a bit afraid of wrapping a blanket around a heater and leaving it on overnight, but I will do it the right way now. My hermetic service kit did have a considerable leak in between one of the fittings which probably didn't help either so I fixed that the best I could. I'm venting out the system now and will then vacuum it down and bake it the correct way then start over. If this attempt fails then it's time to go back to the drawing board and install a low side port. Hopefully the second time is the charm! Understand. Hopefully it will do the trick. For safety, I use a ceramic heater, with about a 1 meter section of aluminum dryer vent hose attached. This allows the heater to be positioned away from the blanket and allow only the hot air to go underneath there. Unfortunately I don't have a picture at the moment. You need to get below 500 microns mercury vacuum to dehydrate the system. If there were any leaks in the system it would not be effective. Most vacuum pumps won't pull down that low if there is any leaking. When the system is tight and dry, it will pull down to around 300 microns while hot; and after you remove the heat the vacuum will pull down further into 75 to 150 micron range.
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jackj
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Post by jackj on May 25, 2023 20:40:46 GMT
Just wanted to post a quick status update while the system is currently baking under vacuum. Things are looking a lot more promising this time around! Sealing the hermetic service kit definitely helped me achieve a much deeper vacuum and after only 2 hours the pump is nearly silent and a fair amount of moisture is obviously being pulled out of the system as evidenced by the droplets of water and cloudy appearance of the pump oil. Probably going to have to do an oil change if it gets any worse, but for now I'm going to not mess with anything and continue making progress. Attachments:
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Post by turbokinetic on May 25, 2023 20:42:12 GMT
Just wanted to post a quick status update while the system is currently baking under vacuum. Things are looking a lot more promising this time around! Sealing the hermetic service kit definitely helped me achieve a much deeper vacuum and after only 2 hours the pump is nearly silent and a fair amount of moisture is obviously being pulled out of the system as evidenced by the droplets of water and cloudy appearance of the pump oil. Probably going to have to do an oil change if it gets any worse, but for now I'm going to not mess with anything and continue making progress. That is an excellent finding. The moisture in the pump is a very good sign that it is working, plus as you said need to change the pump oil. Does that pump have a gas ballast valve on it?
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jackj
New Member
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Post by jackj on May 25, 2023 21:25:40 GMT
Just wanted to post a quick status update while the system is currently baking under vacuum. Things are looking a lot more promising this time around! Sealing the hermetic service kit definitely helped me achieve a much deeper vacuum and after only 2 hours the pump is nearly silent and a fair amount of moisture is obviously being pulled out of the system as evidenced by the droplets of water and cloudy appearance of the pump oil. Probably going to have to do an oil change if it gets any worse, but for now I'm going to not mess with anything and continue making progress. That is an excellent finding. The moisture in the pump is a very good sign that it is working, plus as you said need to change the pump oil. Does that pump have a gas ballast valve on it? An excellent finding indeed, glad things are starting to go in the right direction. And unfortunately this pump does not have a gas ballast valve since it's just a cheap harbor freight single stage pump that I use for automotive applications. I don't have any oil on hand right now so I will have to pause everything while I go get more sadly.
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Post by ckfan on May 26, 2023 11:56:39 GMT
The word automotive jumped out at me. Please be aware that using equipment (gauges, hoses, etc) that has been used on a car system will destroy the windings of a hermetic compressor. The oils aren’t compatible with the windings.
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Post by turbokinetic on May 26, 2023 12:11:29 GMT
The word automotive jumped out at me. Please be aware that using equipment (gauges, hoses, etc) that has been used on a car system will destroy the windings of a hermetic compressor. The oils aren’t compatible with the windings. That is a very good point about the automotive oils. If they used PAG oil which contaminated the gauge set that can be a big problem for a hermetic compressor. The vacuum pump itself should not be a problem.
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jackj
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Post by jackj on May 26, 2023 16:52:55 GMT
Yikes you guys are right about that. I've only used this gauge set twice on my car mainly for testing pressures since I can just charge with the new canned stuff. I never intentionally fed any pag oil through the gauge set, but that doesn't mean there couldn't be some residue left over in the manifold or lines. I did clean out the gauge set with compressed air and a bit of carb cleaner in the manifold itself before starting this project so hopefully that minimized any left over oil residues that may have been present. I'm going to clean it out again then try charging the system again. I let everything bake for about 9 hours yesterday and I pulled out plenty of moisture so I'm hoping for a better outcome this second time around.
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Post by turbokinetic on May 26, 2023 19:18:32 GMT
Yikes you guys are right about that. I've only used this gauge set twice on my car mainly for testing pressures since I can just charge with the new canned stuff. I never intentionally fed any pag oil through the gauge set, but that doesn't mean there couldn't be some residue left over in the manifold or lines. I did clean out the gauge set with compressed air and a bit of carb cleaner in the manifold itself before starting this project so hopefully that minimized any left over oil residues that may have been present. I'm going to clean it out again then try charging the system again. I let everything bake for about 9 hours yesterday and I pulled out plenty of moisture so I'm hoping for a better outcome this second time around. You should be OK with the gauges as long as you don't flow liquid from the can through the hoses and "Wash" the residue into your compressor. Charge in vapor form only and it should minimize any risk.
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marko
7 Cubic Foot
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Post by marko on May 26, 2023 22:04:17 GMT
Yikes you guys are right about that. I've only used this gauge set twice on my car mainly for testing pressures since I can just charge with the new canned stuff. I never intentionally fed any pag oil through the gauge set, but that doesn't mean there couldn't be some residue left over in the manifold or lines. I did clean out the gauge set with compressed air and a bit of carb cleaner in the manifold itself before starting this project so hopefully that minimized any left over oil residues that may have been present. I'm going to clean it out again then try charging the system again. I let everything bake for about 9 hours yesterday and I pulled out plenty of moisture so I'm hoping for a better outcome this second time around. You should be OK with the gauges as long as you don't flow liquid from the can through the hoses and "Wash" the residue into your compressor. Charge in vapor form only and it should minimize any risk. The oil in the hoses and manifold should not be a problem. Shhhhh...., don't tell anyone, just squirt a bit of liquid refrigerant through the hoses....Shssssh
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