|
|
Post by jhigdon2 on Dec 7, 2014 22:02:47 GMT
Well. After some more tinkering with the CA, It's apparent that the 40" of .028" cap tube is just way way off. It only is frosting the evap about 1/2 way up the sides, and I know I've got a full charge of refrigerant. Run amps are too low also. About 2.1. So it's back to drawing board and do come up with a different cap tube. I'll probably start with a length of .031 and go from there. Ugh! I hate calculating cap tubes! It's enough to make a minister swear. Especially since there's no charts to refer to.
|
|
|
|
Post by cablehack on Dec 7, 2014 22:31:22 GMT
Ugh! I hate calculating cap tubes! It's enough to make a minister swear. Especially since there's no charts to refer to. Indeed, something I have fond memories of. You have my sympathy for what you're about to embark on  But, the important thing is R123 has been confirmed. I wasn't expecting the different cap tube requirements though. The cap tube length I saw quoted for Carrene was a lot longer than that for methyl formate despite virtually the same p/t characteristics. |
|
|
|
Post by ChrisJ on Dec 8, 2014 1:21:09 GMT
**As of 12/7/2014 Mr John Higdon has earned the right to swear on the forum with no limit of words, if it helps the cause.
|
|
|
|
Post by coldspaces on Dec 8, 2014 2:01:05 GMT
**As of 12/7/2014 Mr John Higdon has earned the right to swear on the forum with no limit of words, if it helps the cause. Now that's the way to speed up the project! |
|
|
|
Post by jhigdon2 on Dec 8, 2014 2:07:08 GMT
Oh I almost forgot to mention. I poured 200 ml of R123 into a measuring cup and then poured 150 mineral oil into the cup. Mineral oil immediately disappeared and went into solution. So I guess it's miscable.
|
|
|
|
Post by ChrisJ on Dec 8, 2014 2:55:02 GMT
**As of 12/7/2014 Mr John Higdon has earned the right to swear on the forum with no limit of words, if it helps the cause. Now that's the way to speed up the project! Trying to help anyway possible! |
|
|
|
Post by cablehack on Dec 8, 2014 3:34:46 GMT
Oh I almost forgot to mention. I poured 200 ml of R123 into a measuring cup and then poured 150 mineral oil into the cup. Mineral oil immediately disappeared and went into solution. So I guess it's miscable. I thought it might be. There's a definite separation between oil and methyl formate. So it will be interesting to see how having a solution instead will affect things. Where did you get the R123 from and what sort of containers is it packaged in? |
|
|
|
Post by jhigdon2 on Dec 8, 2014 4:12:03 GMT
Ended up getting it on ebay. 50 lb. Metal drum. Has the standard bungs. The large bung on one side has a smaller 3/4" plug in the center. Just screw out the plug and screw in a 3/4" pipe. It's pretty easy to pour into a container. It's crystal clear and has a smell similar to MF. Although not quite as strong.
|
|
|
|
Post by blackhorse on Dec 8, 2014 4:14:12 GMT
Just tinkering with the math-- I get 800 ml of 123 as being 1 3/4 Lb. More or less. With the usual mental math margin of error.  How much formate is the normal charge? I have no idea what the density of methyl formate is at 0 PSIG, but I'm leaning toward you being undercharged. Something to maybe check before you beat yourself up over capillary lengths for which there are no charts. |
|
|
|
Post by coldspaces on Dec 8, 2014 4:48:15 GMT
A little grease on the drill bit and a drill stop to keep from plunging. That's about the best a guy can do. Gives me shudders to. Luckily mineral oil is non detergent and cannot suspend foreign material, so hopefully if there's a metal chip or two, it will just lay in the bottom of sump. I normally tip the compressor so the oil runs away from were I want to drill. Then drill while under some pressure from dry nitrogen so hopefully most of the chips blow out. Cover your eyes! May be adding grease or a magnet next time. Oh and the drill stop is a great tip too. |
|
|
|
Post by jhigdon2 on Dec 8, 2014 14:19:59 GMT
Just tinkering with the math-- I get 800 ml of 123 as being 1 3/4 Lb. More or less. With the usual mental math margin of error. How much formate is the normal charge? I have no idea what the density of methyl formate is at 0 PSIG, but I'm leaning toward you being undercharged. Something to maybe check before you beat yourself up over capillary lengths for which there are no charts. |
|
|
|
Post by jhigdon2 on Dec 8, 2014 14:26:44 GMT
I understand that R123 is roughly twice the weight per volume as methyl formate. Since there is this vast difference, I thought of just going by volume instead of weight. If I remember correctly it takes a little over a litre of MF to charge one of these. As of right now I have 1.1 litre of R123 in the system. Still no change in performance and frost line.
|
|
|
|
Post by blackhorse on Dec 8, 2014 16:16:12 GMT
I understand that R123 is roughly twice the weight per volume as methyl formate. Since there is this vast difference, I thought of just going by volume instead of weight. If I remember correctly it takes a little over a litre of MF to charge one of these. As of right now I have 1.1 litre of R123 in the system. Still no change in performance and frost line. Well you're right, volume is what I actually had in mind, how much it would take to fill the evaporator. Just that liquified gas is usually measured by weight. (Wouldn't you love to see the complications of trying to measure out 134a in a measuring cup?) LOL I wouldn't think there was that much difference, I assumed formate was about the same density, as it's clearly heavier than oil, and most oil comes in at about .85 (7 Lbs/gal). But yeah, 1.1 liter seems like it would fill it. So now the lovely job of trying to sort a cap tube with no Hp rating available. |
|
|
|
Post by jhigdon2 on Dec 8, 2014 20:32:58 GMT
Yeah. I'm looking forward to it fur sure. Lol. I've got a heavy workload most of the week, so I'm gonna have to put this thing on the back burner until Thurs or fri.
|
|
|
|
Post by ChrisJ on Dec 9, 2014 3:15:34 GMT
Yeah. I'm looking forward to it fur sure. Lol. I've got a heavy workload most of the week, so I'm gonna have to put this thing on the back burner until Thurs or fri. Just take it easy on the back. We don't need that giving out. |
|
