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Post by birkie on Oct 21, 2018 13:58:24 GMT
Yeah, it sounds like you did home in on the best charge for it. It'll be interesting to see how a cap tube makes things different.
As far as the rattle.. I don't know about CAs, but I don't like to let the DRs rattle for any length of time. I think the manual says it's harmless, but I kind of disagree. It seems that this condition puts the DRs at risk of siezing, but I don't think there is any evidence of this happening with a CA.
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Post by ChrisJ on Oct 22, 2018 0:52:58 GMT
Yeah, it sounds like you did home in on the best charge for it. It'll be interesting to see how a cap tube makes things different. As far as the rattle.. I don't know about CAs, but I don't like to let the DRs rattle for any length of time. I think the manual says it's harmless, but I kind of disagree. It seems that this condition puts the DRs at risk of siezing, but I don't think there is any evidence of this happening with a CA. I'm not sure about DR's, but from what John Higdon and others have said, I believe the "CA rattling" is actually the intake checkvalve chattering.
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Post by ajc31980 on Oct 22, 2018 1:01:47 GMT
Yeah, it sounds like you did home in on the best charge for it. It'll be interesting to see how a cap tube makes things different. As far as the rattle.. I don't know about CAs, but I don't like to let the DRs rattle for any length of time. I think the manual says it's harmless, but I kind of disagree. It seems that this condition puts the DRs at risk of siezing, but I don't think there is any evidence of this happening with a CA. I'm not sure about DR's, but from what John Higdon and others have said, I believe the "CA rattling" is actually the intake checkvalve chattering. I remember reading that in one of john Higdons threads. But was thinking the check valve only rattled when the machine was working hard. I could be wrong tho and have things mixed up.
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Post by birkie on Oct 22, 2018 3:04:17 GMT
If it is the check valve, then that a different phenomenon compared to the DR. Those rattle when they inhale refrigerant with the oil.
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Post by ajc31980 on Oct 23, 2018 8:18:54 GMT
Food for thought on the rattle . Figure CA will rattle like crazy if the float is full NCGs Because the NCGs keeps the float from opening putting more strain on the compressor /system and eventually where out the seat/ needle letting liquid refrigerant as well as gas sneak bye. So a stuck float would ( thinking this is what’s going on with mine ) with a worn needle would act the same with a reaction of a improper cap tube .. ( sometimes I feel like I’m reading about Records /vinyl and needles/ stylus and proper weight and tracking lol). Just some random 4am thoughts after a long... Monday night at work
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Post by ajc31980 on Nov 16, 2018 8:22:20 GMT
Hi everyone! I’ve been doing some experimenting with heaters. When I bought my CA also bought a spare heater. The original heater Pulls 17.2watts the newer replacement ( that Herb was kind enough to sell me in case I needed one in the future , thank you Herb🙂) pulls 13 watts even though it’s rated for 15watts. Typical voltage reading in my house is 123/124 volts. I decided to try the newer heater just to see what would happen. Surprisingly or at least to me anyway performance went down with a lower wattage cheater. The frost line dropped almost completely off of the right header tank. And the compressor rattle got louder. This was after about 2 days of running. So I switched it back to the original heater and things went back to what I know as normal or well as normal as this machine gets right now lol. So over the last few weeks I’ve swapped them back and forth and always get the same results. what’s puzzling me a bit, is with R123 having a boiling point of 82F versus methyl formate having a boiling point 89F ( please correct me if I have the temps wrong ) One would tend to think you’d be able to get away with the lower wattage heater when using R123. But that does not seem to be the case here. I’m also toying with idea of maybe ordering a 20 or 25 watt heater just to see what the results mite be. I’m also curious, from reading through threads it seems most have good results with these replacement heaters. I’m thinking maybe the results may have something to do with R123 being miscible with the mineral oil whereas methyl formate was not miscible and stayed separate from the oil. I’m hoping some of the monitor top gurus will chime in and share your thoughts on these results.
Could I possibly luck out and just need a little more heat ?
Also if by chance anyone would happen to have a spare 25 watt heater they would like to sell and are willing to ship please PM me 🙂
Thanks AJ.
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Post by turbokinetic on Nov 16, 2018 14:43:11 GMT
Hi everyone! I’ve been doing some experimenting with heaters. When I bought my CA also bought a spare heater. The original heater Pulls 17.2watts the newer replacement ( that Herb was kind enough to sell me in case I needed one in the future , thank you Herb🙂) pulls 13 watts even though it’s rated for 15watts. Typical voltage reading in my house is 123/124 volts. I decided to try the newer heater just to see what would happen. Surprisingly or at least to me anyway performance went down with a lower wattage cheater. The frost line dropped almost completely off of the right header tank. And the compressor rattle got louder. This was after about 2 days of running. So I switched it back to the original heater and things went back to what I know as normal or well as normal as this machine gets right now lol. So over the last few weeks I’ve swapped them back and forth and always get the same results. what’s puzzling me a bit, is with R123 having a boiling point of 82F versus methyl formate having a boiling point 89F ( please correct me if I have the temps wrong ) One would tend to think you’d be able to get away with the lower wattage heater when using R123. But that does not seem to be the case here. I’m also toying with idea of maybe ordering a 20 or 25 watt heater just to see what the results mite be. I’m also curious, from reading through threads it seems most have good results with these replacement heaters. I’m thinking maybe the results may have something to do with R123 being miscible with the mineral oil whereas methyl formate was not miscible and stayed separate from the oil. I’m hoping some of the monitor top gurus will chime in and share your thoughts on these results. Could I possibly luck out and just need a little more heat ? Also if by chance anyone would happen to have a spare 25 watt heater they would like to sell and are willing to ship please PM me 🙂 Thanks AJ.
That's very interesting about the small change in heater power making a big difference in performance.
I used a 25W heater in my DR, and in the CA which I un-seized this week. If you had a chance to listen to the video; the CA ran with no rattling at all after it had run for a few hours and had an NCG purge (possibly incomplete purge, however). The running conditions were somewhat different from yours, as I was running the unit outside of a cabinet, continuously. Furthermore, the ambient temperature was relatively low (peaked at about 60 degrees later in the day).
Seems the main importance of the heater is to ensure the compressor oil sump is hotter than the condenser tubing and float chamber. You want to be sure condensation will not occur in the compressor housing or the oil by making this a hotter, less attractive place to condense. With miscible oil and refrigerant, this may not be a clear yes or no situation. If I am not mistaken, it takes more energy to boil a liquid refrigerant out of a mixture with oil than it does to boil "just plain refrigerant." It may be that the hotter the oil, the less diluted it is and the more refrigerant is available to circulate in the system and raise the frost line. In other words, the higher powered the heater, the better the machine will perform, until there is some plateau point reached.
With my Frigidaire Meter-Miser experiment using the original mineral oil and R152A; that unit seems to start cooling much quicker than the ones still using R12. That makes me think it was easier for the non miscible refrigerant to boil off from inside the compressor housing, and begin circulating.
Just a few thoughts!
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Post by birkie on Nov 16, 2018 16:02:34 GMT
Could I possibly luck out and just need a little more heat ? Glad you had an opportunity to experiment with this! It's definitely worth trying more heat, and seeing if the trend continues With miscible oil and refrigerant, this may not be a clear yes or no situation. If I am not mistaken, it takes more energy to boil a liquid refrigerant out of a mixture with oil than it does to boil "just plain refrigerant." It may be that the hotter the oil, the less diluted it is and the more refrigerant is available to circulate in the system and raise the frost line. In other words, the higher powered the heater, the better the machine will perform, until there is some plateau point reached. Yes, I believe you hit the nail on the head! It's complicated. When they're miscible, the amount of refrigerant that can dissolve in the oil varies based on temperature, and it's never really zero. And different refrigerant+oil combinations have different solubilities at a given temperature. Here's some helpful (if not entirely clearly written) literature. For example: assume that you are looking at the differences in solubility of R-12, R-22, and R-502. At 85°F and 60 psig, a typical oil dissolves about 35% of R-12, 11% of R-22, and 7.5% of R-502 by weight
The article is biased towards compressors that operate with a low-pressure crankcase, so some of the conclusions and advice are not applicable, but it's interesting reading. But anyway, it does seem clear that raising the temperature of the sump won't eliminate the dissolved R123, but will reduce its concentration. So upping the wattage until it behaves "nicely" seems like a good approach! It's a matter of finding the temperature that reduces the solubility to a happy level
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Post by turbokinetic on Nov 16, 2018 17:37:09 GMT
Could I possibly luck out and just need a little more heat ? Glad you had an opportunity to experiment with this! It's definitely worth trying more heat, and seeing if the trend continues With miscible oil and refrigerant, this may not be a clear yes or no situation. If I am not mistaken, it takes more energy to boil a liquid refrigerant out of a mixture with oil than it does to boil "just plain refrigerant." It may be that the hotter the oil, the less diluted it is and the more refrigerant is available to circulate in the system and raise the frost line. In other words, the higher powered the heater, the better the machine will perform, until there is some plateau point reached. Yes, I believe you hit the nail on the head! It's complicated. When they're miscible, the amount of refrigerant that can dissolve in the oil varies based on temperature, and it's never really zero. And different refrigerant+oil combinations have different solubilities at a given temperature. Here's some helpful (if not entirely clearly written) literature. For example: assume that you are looking at the differences in solubility of R-12, R-22, and R-502. At 85°F and 60 psig, a typical oil dissolves about 35% of R-12, 11% of R-22, and 7.5% of R-502 by weight
The article is biased towards compressors that operate with a low-pressure crankcase, so some of the conclusions and advice are not applicable, but it's interesting reading. But anyway, it does seem clear that raising the temperature of the sump won't eliminate the dissolved R123, but will reduce its concentration. So upping the wattage until it behaves "nicely" seems like a good approach! It's a matter of finding the temperature that reduces the solubility to a happy level
For some reason I can't see the article, but will keep trying!
Since that is based on low-side sump compressors, they were dealing with it at low pressures. I wonder how the solubility works out at higher pressures, such as on the discharge side domes we are dealing with here?
I've been suspecting this effect has been what has crippled the R12 converted DR's we have heard about. I don't want to be seen as passing judgment on any one else's work; and don't want to jump to conclusions until I have done my own tests. My DR is still working fine with SO2; and I don't plan to disturb it unless it begins to operate improperly. If a nonworking (but also non burned out) DR comes up in my area, I might try a few things.
As for the CA heaters, I would like to see a higher wattage heater, say 50W used. The intent would be to switch the heater between full wave power (50W) and half-wave through a diode (25W) at certain times. It seems to be the added heat is more important wile running than standby, so possibly switch the heater to half power during standby and full-on during running and see how the unit performs.
Just a few thoughts!
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Post by birkie on Nov 16, 2018 18:59:40 GMT
For some reason I can't see the article, but will keep trying!
Since that is based on low-side sump compressors, they were dealing with it at low pressures. I wonder how the solubility works out at higher pressures, such as on the discharge side domes we are dealing with here? The link is PDF file and not a web page, if that makes a difference. I don't think solubility itself will change with pressure, but mixtures of oil and refrigerant will have a lower vapor pressure than refrigerant alone. So in a low-pressure dome, the oil will have less refrigerant than its solubility limit because the refrigerant will boil of until it reaches an equilibrium concentration where the vapor pressure of the oil+refrig mix equals the dome pressure. In a high-pressure dome like the CA and DR, I think you are pretty much guaranteed to be near the solubility limit dictated by temperature, for a given kind of refrigerant and oil. This youtube video kind of sort of illustrates the effects of lower vapor pressure of miscible refrigerant+oil mixes by applying a vacuum to R134a+PAG vs R134a+PAO oils www.youtube.com/watch?v=YKWA_XAKdtw(warning: it has a soundtrack) By the way, I'd love to try PAO refrigeration oil some time, if the original mineral oil needs replacing. Something like Mobil Gargoyle Arctic SHC 224.
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Post by turbokinetic on Nov 16, 2018 21:52:24 GMT
For some reason I can't see the article, but will keep trying!
Since that is based on low-side sump compressors, they were dealing with it at low pressures. I wonder how the solubility works out at higher pressures, such as on the discharge side domes we are dealing with here? The link is PDF file and not a web page, if that makes a difference. I don't think solubility itself will change with pressure, but mixtures of oil and refrigerant will have a lower vapor pressure than refrigerant alone. So in a low-pressure dome, the oil will have less refrigerant than its solubility limit because the refrigerant will boil of until it reaches an equilibrium concentration where the vapor pressure of the oil+refrig mix equals the dome pressure. In a high-pressure dome like the CA and DR, I think you are pretty much guaranteed to be near the solubility limit dictated by temperature, for a given kind of refrigerant and oil. This youtube video kind of sort of illustrates the effects of lower vapor pressure of miscible refrigerant+oil mixes by applying a vacuum to R134a+PAG vs R134a+PAO oils www.youtube.com/watch?v=YKWA_XAKdtw(warning: it has a soundtrack) By the way, I'd love to try PAO refrigeration oil some time, if the original mineral oil needs replacing. Something like Mobil Gargoyle Arctic SHC 224.
Very cool video! It does make sense to me as I have seen this firsthand with PAG versus AB oil. I recovered R152A from my car, with PAG oil and it kept coming back over and over like they showed. The rubber cap would pop off every few minutes while I was working on the car because the refrigerant was still coming out of the oil. When working on the Frigidaires, even though they hold 4 times as much refrigerant, it took a lot less time to recover the system.
Thanks for the warning about the soundtrack. I hate that and wish they would just explain the process or leave the sound of the recovery pump.
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Post by ajc31980 on Nov 17, 2018 10:41:43 GMT
Wow. Lots of new things to absorb. And I have to get that Damn song outa my head now ! Lol. It was good video tho. I feel I have a better understanding of things now. I’m going to probably order a 25watt and a 50 watt heater. Was it ever really determined which supplier was the best to order from? There are a few mentioned in the thread for heaters in the reference section. I’m not sure who I wanna go with.
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Post by ajc31980 on Nov 19, 2018 2:49:31 GMT
Ok. I’m back to the ca now that the 47 is behaving it’s self again lol. At some point I may get to my clock Ugh. I received a quote from cartridge-heater.com those heaters are pricey little devils. This is what I received in my email today uploads.tapatalk-cdn.com/Has anyone ever dealt with this company before ?
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Post by turbokinetic on Nov 19, 2018 4:48:47 GMT
Ok. I’m back to the ca now that the 47 is behaving it’s self again lol. At some point I may get to my clock Ugh. I received a quote from cartridge-heater.com those heaters are pricey little devils. This is what I received in my email today Has anyone ever dealt with this company before ?
AJ, I ordered my heaters from Nordic and they were very pricey. I believe I paid $50 a piece plus shipping.
Currently, Paul has placed a bulk order for heaters at about $18 per heater. Have you seen his thread?
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Post by ajc31980 on Nov 19, 2018 5:40:45 GMT
Ok. I’m back to the ca now that the 47 is behaving it’s self again lol. At some point I may get to my clock Ugh. I received a quote from cartridge-heater.com those heaters are pricey little devils. This is what I received in my email today Has anyone ever dealt with this company before ?
AJ, I ordered my heaters from Nordic and they were very pricey. I believe I paid $50 a piece plus shipping.
Currently, Paul has placed a bulk order for heaters at about $18 per heater. Have you seen his thread?
Hi David No haven’t seen his thread. I’ll have to look for it. . $18 is a way better price. But in my case I’m looking to get 25 and 50 watt heaters to try out. So I may be stuck paying the higher price. I Did send an email to Nordic as well. Still waiting to hear back from them.
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