View Full Version : It's up and running, but not without problems...
kryptobs2000
04-02-2005, 07:23 AM
Ok, well I got it up. On my 3000+ Newcastle idle, it is only getting -10c according the bios reading (which is way off, but when overclocking it'll get up to 30c). The evaporator reads -28c measured by a dt150. This is when it's not mounted however, havn't read it mounted. Whats wierd is the high side reads 160psi, and the low side reads -10psi. There is however no blockage I know that for a fact. Whats causing this, I figure this has got to be part of the problem.
3/4hp compressor
r502
about 7' of .028 cap tube (I think it's too long, but rather too long than too short, it's easier to take than to add).
I believe thats it, please help. I'm sure shortening the cap tube would help, but there's gotta be somethign else wrong.
edit: Btw, I know it's not undercharged because if I were to add anymore, the compressor really strains to start and can't, it'll fail and just cut off. Right now it strains to start as it is but does so after a few seconds. If I leak more gas out than there is now, it drops temps dramaticaly. (or rather raises them I guess lol).
Jimi...
04-02-2005, 08:06 AM
What's High side and low side?
Redwolf
04-02-2005, 08:53 AM
If you truely have a 3/4hp lowtemp 502 compressor then 7ft .028 might be to short.
Really need more info to make a good diagnotic.. Suction line temp and liquid temp.
If your having problems starting have you checked your start components and what do you have for them?
Epsilon
04-02-2005, 09:54 AM
If the low-side reads -10psi and the temp is -28c, then it's undercharged or a blocked captube i would say. That'sa gigantic superheat :).
wdrzal
04-02-2005, 10:03 AM
I agree with above, slowly add a little vapor into low side, allow unit to stabilize for 5 min between additions,report back.
LardArse
04-02-2005, 10:54 AM
whast the compressor rated for?
you have a big condensor? If so you will need more refrigerant inside, and thus when starting up, the pressure will overshoot the cutoff point.
Just hook up a start capacitor it will take the load off the compressor during startup and pressure will be much less during running.
wdrzal
04-02-2005, 11:05 AM
whast the compressor rated for?
you have a big condensor? If so you will need more refrigerant inside, and thus when starting up, the pressure will overshoot the cutoff point.
Just hook up a start capacitor it will take the load off the compressor during startup and pressure will be much less during running.
Lardarse, what do you mean that pressure will be much less during running,
walt
kryptobs2000
04-02-2005, 11:06 AM
well I found out it does have a start capacitor on it. It's rated as a 3/4hp medium temp compressor. After tweaking it some, high side reads 255psi or about there, low side reads about 2psi. I turned the condensor fan off to bring the high side pressure up. evaporator now reads -28c idle, and well.. actually -28c loaded too, I think I mounted it bad. however, I don't think the compressor will now start, I havn't tried, but I'll try right now and post back.
edit: won't start up, and I talked to my dads friend who knows alot about this, he said if it didn't have a startup capacitor it wouldn't start at all. :confused: :(
wdrzal
04-02-2005, 11:11 AM
not all compressors use them
are you using the correct voltage ?
wdrzal
04-02-2005, 11:20 AM
oh you had it running, you need to wait a few miniutes to the pressure equlizes, or it will not start
kryptobs2000
04-02-2005, 07:38 PM
I waited hours and same problem.
I'm gonna be switching out to a 1/3hp compressor I found, and I mine as well lengthen the capillary tube anyways while I'm at it, so I'll update you guys then/
LardArse
04-03-2005, 08:34 AM
Lardarse, what do you mean that pressure will be much less during running,
walt
Well I made a rig that hits ~ 200 psi on start up which will triggeer the cut off since its rated for r12, but during running only about 150psi, so i had to put in a start cap even if it wasnt supposed to use 1.
kryptobs2000
04-03-2005, 02:52 PM
am I right in using 93" of .028 for a 1/3hp and 502 at 200w load?
gkiing
04-03-2005, 07:36 PM
Cap tube size is independant of compressor power in most situations with these small systems. Try 51" 0.028, and charge until the temp 6" from the compressor is 8f higher than the evap temp converted from the pressure on the lowside gauge.
With that large a compressor it may run ok in a vacuum, you just need to check the superheat (Thats what the instructions above are)
am I right in using 93" of .028 for a 1/3hp and 502 at 200w load?
thats is what i used on rejects unit.
i think thats what chilly starts at also
same mobo/cpu similar gas/compressor
better start long and cut short than go too long straight away.
kryptobs2000
04-03-2005, 08:04 PM
Well I'm getting two different sizes here and both are very different from one another. I'm confused.
hatemi
04-03-2005, 08:08 PM
It realy dosnt matter that much. You can use everything on between 1.5-3m and get it to hold nice temps. Its just a matter of tweaking it to the coldest possible temps. The last sytem I made had 190cm of 0.031 tube in it and it seems to be working nicely. The system before that had 290cm of 0.031 tube and it also worked nicely.
any length will work.
thats why there is no real guide what to use exactly.
ya have to test it for your self.
good insulation on suction and correct amount of gas and 93" to 51" will give ya good supaheat on ya A64" and nice temps depending on how much time you spend tweaking it to load.
The systems act very different with out load compared to load.
if you start long and cut short (little by little)
ya will notice all sorts of things happen.
ie at different lengths of capillary length the head pressure increase and decrease.
kryptobs2000
04-03-2005, 08:14 PM
Well right now I have it at 7' about. Should I just keep that and not worry about it then? Would save me the trouble of having to replace the cap tube.
It realy dosnt matter that much. You can use everything on between 1.5-3m and get it to hold nice temps. Its just a matter of tweaking it to the coldest possible temps. The last sytem I made had 190cm of 0.031 tube in it and it seems to be working nicely. The system before that had 290cm of 0.031 tube and it also worked nicely.
ya beat me to it hatemi, say responce though :stick:
Well right now I have it at 7' about. Should I just keep that and not worry about it then? Would save me the trouble of having to replace the cap tube.
sound like a plan.
whats the suction line insulation like.
also the insulation on the evap/ mobo back and front will make a big difference to load temps.
gkiing
04-03-2005, 09:36 PM
Well I'm getting two different sizes here and both are very different from one another. I'm confused.
It really depends if you want it to hold a large load or have low idle temps.
kryptobs2000
04-04-2005, 07:01 AM
Well I'd like to hold the large load, but if it dosn't make a big difference I'll just keep it as it is. The insulation right now, well I can get pics later. But on the mobo, I got cork tape all over the top half of the back, and same with the front. Then a layer of neoprene. And on the front I have a couple layers, untill it's level with the cpu socket. No insulation on the suction line at all right now. I wanted to get all my problems cleared up before I did that. And it looks like I still have a small leak somewhere as well :(