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Post by coldspaces on Feb 22, 2017 4:27:19 GMT
Update time. When the garage was colder a few weeks ago I finally shut this unit off as it wanted to rattle the whole time it was running. Now that it is warmer I turned it back on for a few days and it worked good. Only rattle was when I first turned it on, after a few minutes it sounded great. After a few days it almost seemed like it was having trouble making enough liquid to open the float so I shut it down for a day.
Yesterday I turned it back on and so far it is running good. The control is a bit jacked up and seems to give some inconsistent cycle times. Overall it is on about 2 minutes average and off around 20 minutes. Sound level is good in the 70 F garage but the 38 flat top is not as loud. Cycles still start at around 235 watts and end at around 200. it is a nice 35 f inside the box. I wondered if it was a bit overcharged the other night as the top 3/4 of the condenser was much warmer than the rest making me think there was to much liquid in the condenser. This was just before it seemed to not be opening the float good though, could be this float sticks a bit, not sure though. I do know the cycles are so short things never really warm up so I am pretty sure it will be better with more heat in the oil. The factory heater in this draws 16 watts. I understand the ckfan is sending me a few that are hotter to try.
Overall it looks like this will work decent but will be a bit louder although I haven't tried it in a scotch yoke yet to see how it compares to my flat top and need too. I do have a CG top that could be "Ginny pig 2.0" It for sure is no were near as loud as 134a or R12 would be, only those of us familiar with them would hear the difference I think. I think the hotter heater will be a big factor as this 152a just seems to condense into the cold oil easier than some refrigerants and yes its still the original mineral oil.
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Post by ckfan on Feb 22, 2017 15:09:42 GMT
Gill, consider those heaters shipped. I'll be sending them off tonight. I'm so happy that these tests are proving successful. I hope that as the weather warms up that this machine continues to perform well. The short off time and long off time have me curious though. I wonder if that is due to a wonky control as you mentioned? At any rate, this is top notch work you are doing here. Hats off to you good sir.
Maybe I will resurrect my DRA with 152a. Who knows?!
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Post by coldspaces on Feb 28, 2017 0:29:57 GMT
Well by the time the heaters arrived my garage was back in the 40's for temp and the poor DR was rattling away again. The new heater is 20 watts, that's only 8 more than the original 12 watt. I was pretty skeptical that 8 watts more would make much difference. I put it in and plugged the refrigerating machine back in. There was no bubbling of the refrigerant from the heater boiling it off,just a steady hiss I thought I could here. To my surprise the first on cycle just a short time latter I could already tell the rattle sounded different. After a few more cycles the rattle left and has not returned. Also the frost line went up and the suction line was even frosting part of the time.
It seemed to be working much better but would go through a weird pattern, cycle a few times without much sound of the float opening, then a cycle were it would open and dump refrigerant in like mad. I had the door open in a mid 50 f ambient at the time, door was left open to get it to run more often. Finally I decided it was a bit overcharged and made a few ounces or so disappear. So far so good, great frost line but maybe a bit high yet, no more rattles and much more even sounding flow through the float.
Watts are still in the 230's at start up and drop to 190-210 by shut down. I haven't timed the cycles again yet.
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Post by Travis on Feb 28, 2017 0:52:58 GMT
Gill,
All of the Nordic heaters I have bought are higher wattage than they are stated. Are those larger heaters actually 20 Watts or are they a bit more?
Regardless, That's great that it's running better. If you need a painted cabinet for a DR for testing just say the word.
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Post by ckfan on Feb 28, 2017 1:08:49 GMT
Glad that you got the heaters. I'm also glad that after the new heater and a burp that it is acting better!
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Post by coldspaces on Feb 28, 2017 1:53:42 GMT
Gill, All of the Nordic heaters I have bought are higher wattage than they are stated. Are those larger heaters actually 20 Watts or are they a bit more? Regardless, That's great that it's running better. If you need a painted cabinet for a DR for testing just say the word. The Kilowat says the original is drawing 16 watts, the new one is 23 watts according to the kilowatt. |
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Post by Travis on Feb 28, 2017 2:08:23 GMT
That's great to know. The 30 watt heater in the DR3 is actually 33 watts.
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Post by coldspaces on Mar 1, 2017 14:04:44 GMT
Monday night a scotch yoke compressor met with R-152A, my type A Globe Top that had previously been converted to 134a is the Ginny pig this time. It is the one in this thread monitortop.freeforums.net/thread/259/travis-brought-me-globe-topThe suction line is still crimped shut pretty good, just like I had it for 134a to work at near normal watts. I evacuated the system and since it originally had 1 & 3/4 lbs so2 I added two cans of duster (20 oz) thinking I would adjust the charge up from there. That turned out to be a mistake it looks like, the system worked remarkably good but It shows signs right off that it was overcharged. Hi head pressure for 152a and frosting back on the suction line. I let it run like that all night and it was still working the next morning. Yesterday I decided to start bleeding of gas a bit at a time till I got it right. After a while the suction line was frosting less and the watts were down to near normal at shut down. Next thing I knew I had evidently let out to much and the float stopped opening. I left it run and warm up to see if more gas would boil out of the oil but all it did was go deeper into a vacuum till the watts dropped to little over 100. At this point I had disconnected the low side so the door could be shut and couldn't hook it back up without getting air in so I decided to start over. I evacuated the system and weighed in the charge this time. I stated with one 10 can and the added 1 oz at a time till the evap was fully frosted. I only have 13 oz in it and so far it was working good and fully frosted including the suction line again. It has been on all night so I will have to go see what is happening this morning for frost line. This ball top had 28 oz of so2 in it originally. I never thought that 152a would need less than half the original charge but it seems the the Scotch Yoke machine is working that way, although the suction line is still crimped. This would suggest that I have the poor DR ginny pig overcharged so I may be bleeding more out of it even though the frost line looks good to see what happens. |
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Post by ckfan on Mar 1, 2017 16:01:45 GMT
Wow, I too am surprised that it took so little to make the ball top frost. Very good work as usual. I'm very excited to see how this all turns out.
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Post by Travis on Mar 1, 2017 16:43:39 GMT
I wondered how your test was working out. Could it be that the DR's are just that much less efficient, as usual?
It makes me wonder how this DR3 would behave on canned air.
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andy
New Member
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Post by andy on Mar 1, 2017 17:33:15 GMT
I would expect the liquid volume to be more important than the weight of the charge. Considering that liquid S02 is substantially more dense than R152a, I would expect it to need less R152a by weight.
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Post by coldspaces on Mar 4, 2017 2:16:29 GMT
I would expect the liquid volume to be more important than the weight of the charge. Considering that liquid S02 is substantially more dense than R152a, I would expect it to need less R152a by weight. I sure wasn't expecting less than 1/2 charge, but its working pretty good. This CG has some too good to believe run times I think. I haven't been out there enough to time it much. I did watch one cycle last night, Garage was 66F Off 10:25:45 On 11:09:50-235 watts-35 F Off 11:15:02-182 watts-31F- 78 Head press. Kilowatt says .08 used in 45 hours at .129 per KW And here are some frost pics from both the CG and the DR, loads have been light, cool garage and not mush door opening. drive.google.com/drive/folders/0B8_jm7K-ahMaNU1oRXBuUWJUN3c |
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Post by ckfan on Mar 4, 2017 2:28:03 GMT
Very nice. I'm glad to hear that both machines are doing well. From the look of the shelf on that DR there isn't hardly any frost on it at all!
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Post by coldspaces on Mar 4, 2017 2:55:38 GMT
Very nice. I'm glad to hear that both machines are doing well. From the look of the shelf on that DR there isn't hardly any frost on it at all! I think that's because the DR is overcharged. |
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Post by ckfan on Mar 4, 2017 3:39:58 GMT
Ah, that makes sense. Since the series shelf gets the refrigerant first I guess that if the unit is overcharged it won't frost over due to being logged with liquid. At least that is my limited understanding.
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