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Post by ChrisJ on Aug 24, 2013 0:29:59 GMT
Did we ever come to a decision on an easy way to unsolder the first screw on the form A machine? I don't have an iron big enough for that, my largest is 60 watts. Would a torch be safe to use just to get the screw loose?
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Post by allan on Aug 26, 2013 2:45:13 GMT
Just added 4 more ounces to my CA2 form B. As you can see frost line is slightly low Attachments:
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Post by ChrisJ on Aug 26, 2013 2:54:13 GMT
I had to slightly modify your post Allen to fix the picture. What browser are you using? Maybe that's what is causing the issues with attachments?
How has the compressor on that machine been? I recall you saying it was better but still clicking?
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Post by allan on Aug 26, 2013 3:00:51 GMT
I had to slightly modify your post Allen to fix the picture. What browser are you using? Maybe that's what is causing the issues with attachments? How has the compressor on that machine been? I recall you saying it was better but still clicking? I use Safari on my iPad. Are there instructions some where that I can study about this site? The unit works great but still has some rattle to it. I installed a 25 watt heater and added 4 ounces of MF today to raise the frost line. Anxious to see the results tomorrow |
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Post by ChrisJ on Aug 26, 2013 3:10:05 GMT
I had to slightly modify your post Allen to fix the picture. What browser are you using? Maybe that's what is causing the issues with attachments? How has the compressor on that machine been? I recall you saying it was better but still clicking? I use Safari on my iPad. Are there instructions some where that I can study about this site? The unit works great but still has some rattle to it. I installed a 25 watt heater and added 4 ounces of MF today to raise the frost line. Anxious to see the results tomorrow I've never tried Safari on here. I mainly use IE or Chrome depending on my mood or where I am work vs home. See if this section is of any use to you : www.proboards.com/user-guide/posting |
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Post by ChrisJ on Aug 29, 2013 21:49:39 GMT
When is the best time to judge the charge level with a cap tube? When a machine is under light load, or heavy load?
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Post by cablehack on Aug 29, 2013 23:45:08 GMT
My plan is to finalise the charge level with the machine under light load - that is, nothing in the cabinet, and the door shut for several hours. My reasoning for that is that most of the time the machine will be running under those conditions - once all the heat has been taken out of the things inside the cabinet then it has no more work to do except offset insulation losses. Heavy load is only a temporary thing.
Just from running the CA-1 outside the cabinet, I get the impression that I'm going to find a little less refrigerant is going to be better than more. So, I'll be erring on the lesser amount of charge. I think the important thing is to get the level correct in the right header tank so the oil still circulates. An important thing I have noticed is the level drops after a few minutes running, so don't be tricked by that. I think that is because with the compressor off, the liquid all drains into the evaporator (no valve to stop it), so upon start up there's actually more than normal in there. It takes a few minutes for the excess to evaporate off and return to normal level. I suppose that one doesn't want to add so much liquid that after rest some gets sucked into the compressor.
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Post by ChrisJ on Aug 29, 2013 23:52:15 GMT
My concern is I want to avoid slugging and I'm assuming the time when that may occur is when the condenser is cold and the machine first starts. SO it sounds like that is the time to check for the highest level?
I know rotaries tolerate slugging pretty good but I doubt it happening everytime it starts would be a good thing.
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Post by cablehack on Aug 30, 2013 0:12:01 GMT
Yes, I agree with your reasoning - I know the CA compressor is built like a battleship but best not to stress it if we don't have to.
So, as long as it's not frosting right up to the low side rubber grommet on start up that should be ok.
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Post by allan on Aug 30, 2013 3:10:20 GMT
My concern is I want to avoid slugging and I'm assuming the time when that may occur is when the condenser is cold and the machine first starts. SO it sounds like that is the time to check for the highest level? I know rotaries tolerate slugging pretty good but I doubt it happening everytime it starts would be a good thing. The suction line heat exchanger on my CA2 form B with cap tube is doing a good job keeping the suction line warm. My box stays at 31 F with cut out at 5 F evap. Anytime you grab suction line it is very warm, feels same temp as liquid strainer. Pump should only be feeling gas, no liquid |
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Post by ChrisJ on Sept 13, 2013 2:07:33 GMT
cablehack, I figured I'd continue here as this is really the appropriate place for it I guess.
I don't have a scale small enough for this unfortunately. However if I add say 1/3 of my bottle and fire it up and look at the frost line for a bit I'm sure I can get it about right. I'm curious about a few things though such as why does everything claim both headers should be half full. That never, ever seems to happen.
I'm also curious how much refrigerant can go in before the suction line starts to frost. Has anyone had their suction line frost at all yet?
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Post by cablehack on Sept 13, 2013 2:34:56 GMT
Yes, you should be ok putting in 1/3 of your bottle to start with. I don't think the headers have to be exactly half full - something between 1/4 and 3/4 should be OK. Once my CA-2 settled down, it maintained half full on both sides with no problem, until next time the float valve played up of course. At the moment, there's frost on both headers, but it's been going good for a while now.
My CA-1 has uneven frost simply because I haven't put enough in it - but that will be sorted out once I've got the cabinet finished.
Interestingly, notice how in the CA manual, they just say to empty the whole bottle of MF into the system if you think it needs refrigerant...that tends to make me wonder how critical the level actually is. They don't say to add slowly and check the frost line as you go.
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Post by ChrisJ on Sept 13, 2013 2:40:36 GMT
So wait,
You're CA-2 has equal frost? Mine always had frost to the top of the left header, and half way on the right header. Of course both had bad float valves.
I don't know how critical an overcharge is but I don't see slugging to be good for the compressor especially since the vane is locked in position. Of course, there is no valve on the exhaust and apparently methyl formate does NOT "water" the oil down as the two don't mix.
Maybe the CA compressor doesn't mind the occasional slug?
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Post by ChrisJ on Sept 13, 2013 2:43:44 GMT
Actually I just noticed in the one picture of the CA-A it does appear to me, to have a reed type exhaust valve.
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Post by cablehack on Sept 13, 2013 3:06:57 GMT
Here's pics of my CA-2 I took when I first had it running. As you can see, I probably put in a little more than necessary, but it didn't frost into the compressor low side line so wasn't worried. I would not be comfortable about frost beyond the low side rubber grommet, but there's no problem with the small overcharge I have here. As long as the valve doesn't stick, the levels remain even. It hasn't stuck for a long time now - instead the float seat wear is now evident, so the evaporator doesn't cool down to the temperature that I know it's capable of. But that hasn't affected the frost line. It's running at about 3 mins on, 10 mins off depending on room temperature. drive.google.com/drive/folders/0B8_jm7K-ahMaemtYMUpKbFdVMEU |
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