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Old 09-22-11, 11:55 AM   #11
Xringer
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Default Vac testing

Got the pressure down to 1200 microns yesterday afternoon in about 3 hours.

Must have been a lot of moisture in there..

Today, I took the manifold and one hose out of the rig and got it down to 600 microns on the first 25 minute run!
That was using old pump oil that has two hours on it from yesterday..(It's warm again outdoors. 72F).
I'm going to let the pump cool off for a while and see if I can get down to 200 microns.
If it can't make it, I'll do another oil change and try again..

I've got to start studying up on how to get my can of R410A into the system..
Need to call some HVAC guys from work.. If they aren't all retired too!

http://cgi.ebay.com/410-R410-R410A-R...-/230518803649

I'm starting to think maybe the POE lube in the system might not be too badly damaged to re-use for my tests..


Last edited by Xringer; 09-22-11 at 12:49 PM.. Reason: adding ebay link
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Old 09-22-11, 05:35 PM   #12
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Default Refrigerant



I've been wondering if a 200 micron vacuum inside the large outdoor coil would be enough to suck in 28 oz of Refrigerant??

I would remove the test loop, and attach the Refrigerant hose loosely on the 1/4" line set port (Liquid Line).
Then, shoot a tiny bit of Refrigerant gas (bottle right side up) into the 10" fill hose to push out the air,
while quickly tightening the fitting.

When the liquid line service valve was opened (hex key), the vacuum would allow any liquid Refrigerant
that was released from the tank (upside down) to flow into the main coil, via the Strainer, EEV and cap tubes.



Of course, it would be only legal to DIY, if the Refrigerant was Propane..
Just wondering if this would work..?.
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Old 09-23-11, 03:16 PM   #13
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Now that I've been looking at this for a while, there is no easy way to feed Refrigerant into a completely vacuumed system,
(with a vacuumed line-set attached).


Because of the Schrader core valve, needs +pressure inside the line-set to stay sealed.
If there is a vacuum in the line-set, removing the pump hose will allow the 14 PSI
to be sucked inside the line-set. If the large service valve was open, air would
fill the whole system. The Scharder core is basicly a one-way check valve..
Which can be pulled open, from the inside (by low pressure).




Notice that Pump Down info.. That's going to come in very handy, after I get all the testing done.
Since I might move it over to the house and deploy it on a new HX or another Sanyo indoor unit.

Last edited by Xringer; 09-24-11 at 09:38 PM.. Reason: Pump down note:
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Old 09-24-11, 11:13 AM   #14
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Default Vac stalling

It seems like the system is out-gassing something (maybe gunk from it's filter) at about 500 microns.
I'll take it down to 500 and within a few hours, or overnight, it will drift back up to 600.
Whatever process(leak?) is going on, it seems stop at 600.

Maybe just below 600 microns is the 'point' where POE oil gives up it's water molecules?

My check-vac process is to close the service valve and let the lines get down to 300,
before opening the service valve again. And see the meter jump back up around 600!

When left to run for a while, it will get down to 550-570 but then the micron gauge
starts flashing the stable LED.. The operation just stalls..
I'll try changing the oil again and see if there is any improvement.


This is not at all like vaccing a line set.. I'm starting to wonder if there is something
inherent to the system that is going to regulate the pressure to stay at 600??
I'm saying this, because the system is designed to keep up to 500 PSI inside..
I wonder how low they go at the Factory, before charging?
Heck, they might just be doing a nitrogen flush and then flushing that with R410A gas,
followed by the liquid charge.... Since that seems like a cheaper way to go..


Last edited by Xringer; 09-24-11 at 11:21 AM..
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Old 09-24-11, 02:18 PM   #15
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Default

You might be getting permeation through your hoses and a small amount of leakage at the valves when opening or closing them under vacuum. Have you tried heating the compressor and internal piping while pulling a vacuum?

http://www.jbind.com/pdf/Deep-Vacuum-Principles.pdf
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Old 09-24-11, 03:17 PM   #16
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Now, I'm vaccing on the narrow tube (liquid) port and using that small hex-key valve.
I changed the hose config around, so the micron meter was off a 'T' on the vac pump.
The meter seems to be steadier now and the vacuum seems better.
I just got the system down to under 300 microns in about 30 minutes.
(After changing the pump oil).

You are right on about the valves.. I can turn the Hex-key and see very little,
if any change when the pressure is up around 500-600.
But, down at 300, it's very visible. I can turn the hex-key a 1/4 turn
and the loss pops right up.. It went up near 400 as I played with it..

So, I'm just gonna hafta be happy with 200-300, and put some Refrigerant in,
before anything leaks down, so I'll have Positive pressure inside the unit.
Once it's got positive pressure, those service valves should be fine..
They are turned all the way out to their stop-seals, and capped over for good measure..
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Old 09-24-11, 04:43 PM   #17
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I got out the Coronas (w/limes) and had the vac down to 250 microns when my HVAC buddy showed up.
We removed the pump and connected up the R410A can on it's shorty line with release button.
Flooded the line out a few times with gas, then cranked the fitting down tight,
then added liquid R410A to the system. (At long last)! It sucked it up!
We pulsed the button lightly, and slowly(30 min) added 10 or 15 oz.
The rate-of-fill slowed down when the pressure got up around 138 PSI.
(The bottom of the coil dropped down to 60 F).

Later, when I have 230 power to the system, I'll reconnect the test loop, vac it out,
so we can add the rest of the 28 oz can, using the normal low pressure side method.
28 oz will bring it to 40% of a factory charge.
I'm not sure if that will be enough to check the compressor with my micro test loop.
If it seems squirrel, but cooling works, I'll get another can so we can get it
charged to 80% factory.. Which should be plenty for a medium short line-set.

I've also added a long wire up to the T-Run pins button on the controller PCB.
I have a toggle switch on the end of the wire, so I can figure out how T-Run runs. (from a safe distance).
There is come confusion over the T-Run pin assignments.
Since it looks like a plain logic input that gets grounded to run, it should be safe to hack.
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Old 09-24-11, 05:00 PM   #18
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Quote:
Originally Posted by hotwire View Post
You might be getting permeation through your hoses and a small amount of leakage at the valves when opening or closing them under vacuum. Have you tried heating the compressor and internal piping while pulling a vacuum?

http://www.jbind.com/pdf/Deep-Vacuum-Principles.pdf
Thanks for the doc!! It was Very helpful..

"There are many evacuation level recommendations
including the statement “evacuate the system to below
200 microns.” This should not be considered. Note we
say “system” because it is possible to evacuate piping or
some component other than the compressor to below
this level. Refrigeration oil has a vapor pressure and by
going below 200 microns, you will degas particles of the
refrigeration oil. By changing the makeup of the oil, it will
no longer be a true lubricating oil."


I hope that I didn't vaporize all the POE in my system by going to 250!!
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Old 09-24-11, 08:42 PM   #19
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I am glad the doc helped. I would think you should be fine with only going to 250 microns. If you were super worried about the condition of the oil, I think they sell Ph test strips to check it for acidity.

Have you had a chance to check the factory service manual and do a resistance test of the windings in the compressor motor?
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Old 09-24-11, 09:32 PM   #20
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I'm not sure how to get at that oil. I don't think that more than a couple of tea spoons was lost.
The oil that found out in the open last week, seemed like brand new oil..

I have not checked the motor windings, since the motor was still running,
when I found the system had very low pressure and took it out of service.

I'm not too worried that it won't crank over.. Maybe tomorrow,
I'll get some time to hook up the test gear and see if it can do some heat pumping.

It would be great if it works. Like finding $1,700 in the garage.. Got my toes crossed.
Otherwise, it's going to turn into a parts mine for the other unit..
(They have the same built date and lot number)..

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