-49.2c at 1 bar...
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-49.2c at 1 bar...
Well it looks like my 3 compressors in series are doing the job after doing a triple evac adding a bit of 402a between each pull down i've changed the moisture indicator in the sight glass from an almose orange color(middle bottom color in pic) to a dark purple :D :p: i think its almost ready to be charged and test run for the first time.
Wooha cant wait harleybro!
UPDATE!!
3 update posts tonight since i got alot of new pics for u all :D
I charged the 2nd stage tonight and the whole 2nd stage pretty much fosted up lol in a matter of a few seconds (this is 402A btw co2 coming later this week i hope). There wern't any bubbles in the sight glass after charging the system but look at pic 5 see if u can see a problem. :eek:
Thats right 260psi and it went higher it went up to 350psi than the pressure switch came into play and cut out shutting down the 2nd stage compressor (good to know that it works right) and nothing exploded (another good thing to know). After recovering some gas from stage 2 and switching cap valves to the shortest one (15") things were looking alot better. In pic 1 thats the temp of the suction line right before the compressor on stage 1 not bad for a start.
I did some insulating to the 2nd stage discharge from the hx and the suction line but ran out early so ill have to get some more tomorrow.
I ran the system again after doing the insulation and the sction line temp went down a few degrees and so did the pressure on the high side.
I also did alot of work to the box as well I put some blocks along the wall just taller than the evap to make a sitting base for the floor of the box (pic2).That was all i was gonna do to the floor of the box for now but than i remembered i had some old grills from a film projector lying around so i cut them to size and fit one on the inlet and one on the outlet to keep things from falling in the holes. They look kinda nice if u ask me :D :woot:.
Quote:
Originally Posted by skate2snow
also the oil in the compressors will absorb some refrigerant as well and mess with pressures.
Also your second stage should be a lot colder than that running that sort of vacuum with r402 ie isn’t it -49c at 0psig?? On pressure charts.
To get better more accurate temp readings insulate where you have attach the probe.
Things are different with c02 need mass flow so its hard to say how it will perform once recharged. But I think you will see some nice results with r402/c02 blend.
You should turn that chill box into a computer case chiller, will do wonders for condensation if sealed properly. Seen a few members do this at extreme systems forum, getting great results on air cooled systems (-ve die temps bot gpu and cpu, no need for cpu/gpu blocks attached to processors.)
The probe was just sitting in the box shouldn't have to insulate it to anything but i think i need to increase the airflow that 1 80mm fan just isn't cutting it. How could i keep frost from building up on the evap?Quote:
Originally Posted by kayl
Don't capacitors not like the cold?? I read somewhere on xs that its not a good idea to super chill some of the components on ur mobo.
What temp do i need to be able to condence co2? isn't it like -25c?
O and btw with the condensor fan running and the 2 compressors running the total amperage draw peaked at 9.4 that pretty low considering each compressor can draw 10.5 amps max EACH.
Ps. how many extra degrees would i gain by hooking up the cx?
the low amprage is because you don't have a load on the system,
also the lower the low side pressure less current draw, especially in vacuum.
i have seen a few more -c's when insulating probes to copper tubbing give it a try.
check this link out.
http://forums.extremeoverclocking.co...d.php?t=172343
this is just one of the guys projects there, great results.
I replaced the 12v 80mm fan for a 90mm high rpm 120v fan. And i use some of that Great Stuff foam to seal any cracks in the box.
Hows this for temps using 402A?
eww.. in such deep vacuum, your system won't handle any load at all. You could reach -67.3c too with a single stage with no load like that. The 2nd compressor is a waste of energy as long as you don't put some co2 or w/e in it imo. Anyway, good job always nice to see thoses kind of temps! :) Also, remember that most ppl use celcius to show results it look more impressive in farenheit but it could trick ppl lol!
I have yet to see a single stage reach -67.3c on xs.
Hmm I bet any of the pros here can get -67c with 402a unloaded. This is no hard task, if I had r402a I would proove it to you. I did -63c with propane long time ago, guess what when I added a load on it it was -20c...Quote:
Originally Posted by _HL4E_HalfLife_
About some of these other things i asked in a previous reply that never got an answer to:
Don't capacitors not like the cold? I read somewhere on xs that its not a good idea to super chill some of the components on ur mobo.
What temp do i need to be able to condence co2? isn't it like -25c?
How many extra degrees would i gain by hooking up the cx?
caps loose capacity when cooled down to much.Quote:
Originally Posted by _HL4E_HalfLife_
if cooled down too much they dont do anything anymore and just let the current run through... i think cooling caps below 0 degrees celcius is useless
Quote:
Originally Posted by _HL4E_HalfLife_
my co2 cascade did -66c Hx out first stage (hx intemps would have been colder).
This was done using just propane and was being loaded by -100c second stage.
Seen a few sinlges do below -70c with r404a and r507, r402a should get even better temps again.
Loaded temps are what ppl are interested in on the forums though really.
I know i can do better than -89.5f because i still have to insulate the cap tube and some suction line at the compressor. Should i insulate the accumulator that every rotary has on the side of it as well?Quote:
Originally Posted by kayl
you also insulate the high side on the second stage.
U mean after the HX right?Quote:
Originally Posted by wdrzal
I always insulate the accumulator that comes on the rotaries,Quote:
Originally Posted by _HL4E_HalfLife_
i do it because surly some extra heat is added by leaving it uninsulated.
Hence reducing the load, I may be incorrect in my logic though.
and an accumulator will get cold and when not insulated you will have serious condensation on it.
Its getting better and better.. and as jack said. better to insulate
But isn't the accumulator there to boil off any liquid that made it past the evap? so wouldn't insulating it basicly kill the purpose of the accumulator since there wouldn't be any more heat to boil the liquid off except from the compressor itself but it may be too late than.
in your second stage a uninsulated accumlator will add load to the system.building a cascade is not like building 2 single stage systems coupled by a hx