Mini-Split Charging help please

anzohaze

Well-Known Member
134a is easy and you can buy it at o'reilly. charging it until compressor stops cycling works great. or they have a meter on the charge kit that tells you when it's good.
never heard of charging to a pressure of 510 and 70, that is a huge head pressure, to do it properly, length and size of pipe and subcooling all need to be considered for 410a
My ideal air mini split calls for that pressure from what I remember I'll post A Pic I could be and probably wrong but I as well said that was a damn high head pressure
 

chuck estevez

Well-Known Member
My ideal air mini split calls for that pressure from what I remember I'll post A Pic I could be and probably wrong but I as well said that was a damn high head pressure
the first 410a systems ran very high head pressures, you could have an older version
 

cbdprospector

Active Member
About as cheap as they get new. Sucks because it probably will be a one time use for you.
http://www.amazon.com/Fieldpice-Digital-Vacuum-Gauge-Alarm/dp/B00DMFHF0I/ref=sr_1_2?ie=UTF8&qid=1431378690&sr=8-2&keywords=micron gauge
I need to figure out how to tap into the local scene cause I'm sure lots of folks could use help with this.
Well, I'm certain I have a leak. I held the vacuum overnight on the manifold and got a small drop. This is probably because I don't have a $150 torque wrench....dammit. So I guess there is a possibility that I either under or over tightened the fitting. I'm thinking I could get some nitrogen and pressure test to locate the leak....(?) As for a scale, is something like a digital fish scale accurate enough to fill with?
 

Merkin Donor

Well-Known Member
Well, I'm certain I have a leak. I held the vacuum overnight on the manifold and got a small drop. This is probably because I don't have a $150 torque wrench....dammit. So I guess there is a possibility that I either under or over tightened the fitting. I'm thinking I could get some nitrogen and pressure test to locate the leak....(?) As for a scale, is something like a digital fish scale accurate enough to fill with?
If your manifold has a micron gauge and you didn't go up over 1000 microns overnight you are fine. But I'm not sure what you're using because there is no "drop" on vacuum unless you are pulling one, only rise. Any scale that accurately displays lb's and oz's would work as long as you can use it with the bottle upside down. Yes nitrogen will work, run it up to 300-400 psi and check with a bubble solution. You've got four flare fittings that you may want to disassemble and check all the lips for cracks or deformities. if you have an HVAC supply house around go pick up some of this stuff and apply yo all the matting surfaces and threads (just a drop or two).
http://www.centurytool.net/RT201B_Refrigeration_Technologies_NYLOG_BLUE_p/rt201b.htm
http://hvac-talk.com/vbb/showthread.php?1279551-REVIEW-Nylog-Gasket-and-Thread-Sealant
 

cbdprospector

Active Member
If your manifold has a micron gauge and you didn't go up over 1000 microns overnight you are fine. But I'm not sure what you're using because there is no "drop" on vacuum unless you are pulling one, only rise. Any scale that accurately displays lb's and oz's would work as long as you can use it with the bottle upside down. Yes nitrogen will work, run it up to 300-400 psi and check with a bubble solution. You've got four flare fittings that you may want to disassemble and check all the lips for cracks or deformities. if you have an HVAC supply house around go pick up some of this stuff and apply yo all the matting surfaces and threads (just a drop or two).
http://www.centurytool.net/RT201B_Refrigeration_Technologies_NYLOG_BLUE_p/rt201b.htm
http://hvac-talk.com/vbb/showthread.php?1279551-REVIEW-Nylog-Gasket-and-Thread-Sealant
It doesn't have a micron gauge, just a compound gauge. What I meant by "drop" was, I shut off the vacuum and line and left the gauge on overnight. Here was the readings:
gauge.jpg

Obviously not as accurate as a micron gauge but it seems to show a slight drop. I have a digital hanging scale that shows lbs and oz, I can strap and hang the bottle with it for sure. I'll pick up some of that flare sealant you suggested, I used up the one that came with the system.
 

Merkin Donor

Well-Known Member
It doesn't have a micron gauge, just a compound gauge. What I meant by "drop" was, I shut off the vacuum and line and left the gauge on overnight. Here was the readings:
View attachment 3416846

Obviously not as accurate as a micron gauge but it seems to show a slight drop. I have a digital hanging scale that shows lbs and oz, I can strap and hang the bottle with it for sure. I'll pick up some of that flare sealant you suggested, I used up the one that came with the system.
That's a tough one, a vacuum will settle out after a bit and the numbers always go up. At this point it's kind of your call because you can chase your tail forever because of not having all the equipment. At this point I would base how you proceed on your operational needs. Do you have time to spend or are your plants in jeopardy. The environmentalist part of me says "no leaks, period" the realist says charge her up, monitor your output temps and if they start climbing add 410 to bring them back in line and maybe a shot of Nu Calgon Easy Seal (there is risk with this so do your due diligence). One thing I never asked in the beginning, did you find oil all over any of the fittings? Refrigerant oil should lead you to the source of the leak.
 

cbdprospector

Active Member
That's a tough one, a vacuum will settle out after a bit and the numbers always go up. At this point it's kind of your call because you can chase your tail forever because of not having all the equipment. At this point I would base how you proceed on your operational needs. Do you have time to spend or are your plants in jeopardy. The environmentalist part of me says "no leaks, period" the realist says charge her up, monitor your output temps and if they start climbing add 410 to bring them back in line and maybe a shot of Nu Calgon Easy Seal (there is risk with this so do your due diligence). One thing I never asked in the beginning, did you find oil all over any of the fittings? Refrigerant oil should lead you to the source of the leak.
Plants are not in any jeopardy, I dragged my portable in there so they are staying cool for however long I need. I only saw some refrigerant oil on the initial leak that I found with a leak detector I bought. I also didn't find any leaks with that detector after I fixed it so I'm thinking I should be good. At this point I'm more concerned with the fill and making sure there is no air in the line when I refill. I have a hose and an adapter that I can take from my manifold and run it straight from the bottle to the low service port - it just doesn't have the ball valve on it.. Also sounds like removing the line fast is critical. What happens if air does get in there? Do you have to start over?

Thank you again for all the info!
 

Merkin Donor

Well-Known Member
Can you post a pic of the manifold/vacuum setup you are using? Can you duplicate this setup with your equipment?
If so you've pulled the vacuum, shut off low side valve and just attach tank and duplicate their setup but before you open the low side crack the yellow line open at the manifold allowing a little 410 to escape to purge the air (non-condensable) out.
 

Merkin Donor

Well-Known Member
Also I would add most of the initial charge to the system before turning it on. Add it in slowly too, you just have to crack the valve open a little bit.
 

cbdprospector

Active Member
So on this setup, it's the same idea except I don't have to unhook anything. I'll still shut off the low side to hold in the vacuum - purge the air from the line - open the low side valve and bring in most of it (slowly) with the unit off. Once I'm close, I turn on the until and measure the temp until I hit 54-55. .
 

Merkin Donor

Well-Known Member
Yes, then just crack the valve a little and you will see the refrigerant in the sight glass. just add it slow and check temps. Once you are where you want to be close the tank valve and open the low side (with system running) this will pull the last tiny bit of 410 out of your manifold. run it like that for a few minutes then close the low side, disconnect your lines from the system. there might be some left in there so be careful.
 

cbdprospector

Active Member
Yes, then just crack the valve a little and you will see the refrigerant in the sight glass. just add it slow and check temps. Once you are where you want to be close the tank valve and open the low side (with system running) this will pull the last tiny bit of 410 out of your manifold. run it like that for a few minutes then close the low side, disconnect your lines from the system. there might be some left in there so be careful.
I can't thank you enough for the valuable information. I really really appreciate it. I tried the digital fish scale - it didn't work - it kept wanting to hold on the weight and stop. So I ordered a refrigerant digital scale, it will be here thursday. In the meanwhile, I just vacuumed and closed off the low port to keep it sealed until I'm ready.

I'll let you know how it goes!
 

Merkin Donor

Well-Known Member
No problem! Bummer, try using and returning if you can. :twisted: Otherwise keep it around, you might be able to recoup some cost by helping other growers with their systems.
 

cbdprospector

Active Member
Thought I would give you an update. I did the recharge last Friday, I followed the procedures and it went perfect. The scale was the key, getting the weight exact was a great feeling. The output is blowing 49 degrees at it's lowest setting though, didn't know if that's a blessing or indication I something it wrong - but it's working great. I took my halogen detector and turned it up to high and found 2 real small leaks, I had to put the sensor tip right up to the flare connection to detect it. I tightened it and didn't get a reading. It's been running cold - a HUGE difference from the portable I had in there. It's such an overkill of a system - a 4 x 4 x 8 tent - that it takes nothing for it cool the area. I threw in my dehumidifier and my sealed room is complete, just in time for me to flip to flower!

Thank you so much for your generous help - it saved my ass. and hopefully this thread will help others in my position.

No problem! Bummer, try using and returning if you can. :twisted: Otherwise keep it around, you might be able to recoup some cost by helping other growers with their systems.
Nah, I don't know anyone who grows - except my helpful friends here! I do this to grow a 1:1 thc/cbd strain for my dad with ALS and no one knows about it. I tell no one, that's why it's so hard for me to get help. RIU has always pulled through when I needed it.
 

4runner1965

New Member
This is a great forum, I am in the process of recharging my Daikin mini split that lost all refrigerant and all this reading it's been so helpful, thanks again. I wonder if Merkin Donor still around since this is a very old post. Thanks again.
 

Merkin Donor

Well-Known Member
This is a great forum, I am in the process of recharging my Daikin mini split that lost all refrigerant and all this reading it's been so helpful, thanks again. I wonder if Merkin Donor still around since this is a very old post. Thanks again.
Just start a new thread with your questions, lots easier than having it buried in the back of an old thread.
 
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