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paradiseair
23-03-2007, 03:23 AM
410-A is an azitope refrigerant wich is a blend.
Then how does the manufacturs say it has an even leak rate?
If it does have an even leak rate why do you only charge in liquid form?
I know that mixing mineral and polyol ester oil is bad,
but what is the result, what does it do exactly.
Polyol ester is water absorbant but why cant a vacume pump remove the water, 28" Hg water should boil out?
Will the oil realy absorb water threw plastic?
How mutch mosture can it absorb?
How do you test the mosture content?
How fast will it absorb, or how much is too much?
Sorry I am a horible speller

NoNickName
23-03-2007, 08:58 AM
410-A is an azitope refrigerant wich is a blend.
Then how does the manufacturs say it has an even leak rate?

Because azeotropes are mixtures that cannot be distilled.



If it does have an even leak rate why do you only charge in liquid form?

Why not?



I know that mixing mineral and polyol ester oil is bad,
but what is the result, what does it do exactly.

They can be mixed, but the mineral will not dilute in refrigerants without chlorine and will clog filters and will cause bad heat transfer.




Polyol ester is water absorbant but why cant a vacume pump remove the water, 28" Hg water should boil out?

It will take days and will pollute the pump oil. A vacuum pump with ballast is necessary, but probably not enough.



Will the oil realy absorb water threw plastic?

What plastic?




How mutch mosture can it absorb?

Enough to damage the compressor motor.



How do you test the mosture content?

With acidity test. Pour some drops of oil in the test, and if color turns, it means that it is too acidic. Like a pregnancy test.



How fast will it absorb, or how much is too much?

Fast enough and so much, that you can't allow any quantity of moisture to ingress. Too much is around 5ppm.

momo
24-03-2007, 12:46 AM
Naive question (?) vacuum pump ballast -what are you refering to?
There are screw valves on some pumps, usually kept closed. Some secret of old engineers (our profs skived off this one!)

NoNickName
24-03-2007, 11:32 AM
http://www.absolute-vacuum.com/images/e2m8two.jpgThe ballast is the knob from where the water vapour, machining oil and other evaporatable liquids are expelled before entering the vacuum pump oil.
You see it in the image. One of the three black knobs is the gas ballast.

momo
25-03-2007, 03:28 AM
Thanks from "Spain" to Italy:), even a parts breakdown of my 1/2HP, the manual and others I consulted knew. :eek:
Because of the possibility of moisture ingress into the POE oil: I usually run mine till warm before counting a reasonable vacuuming time - since the main outlet sometimes "steamed" I extended the run time, but I will now use the ballast as well now to avoid oil pollution.

Since my 1/2HP is dual stage is the ballast venting from the first stage?

PS any other comments of interest about vacuum pumps?.

goodguy
25-03-2007, 04:23 AM
Paradiseair, I was told once by a Copeland representative that even in the deepest vacuum, Poe oil can still retain moisture and the only true way to remove all the moisture was to change filter driers, or have a oil filter in a oil return line (if possible)
Also, alco has a moisture indicator (sight glass)that will change color with respect to ppm of water and liquid line temperature, total ppm is figured out by using the graph supplied with sight glass.

The MG Pony
25-03-2007, 07:34 AM
POE bloody well is a drier the way that stuff grabs on to the moisture! as one said it best, the stuff is a bloody detergent more so then an oil!

taz24
31-03-2007, 01:53 PM
Paradiseair, I was told once by a Copeland representative that even in the deepest vacuum, Poe oil can still retain moisture and the only true way to remove all the moisture was to change filter driers, or have a oil filter in a oil return line (if possible)


Synthetic oil is hygroscopic, If moisture enters the oil it can't be removed.
Once contaminated with moisture the oil is US and will need replaceing. Dryers and even vac pumps will not remove the moisture.
the moisture changes the state of the oil and binds to it at the molecular level.
New oil in an open container will be contaminated within 10 hours of exposure and will be unusable within 24 hours.
Synthetic oil must not be exposed to air under any circumstances.
Only use enough that is required for the job and the excess will need to be correctly disposed of.

taz.

goodguy
31-03-2007, 02:27 PM
Taz, Maybe it was just a sales pitch but, Alco claims that there EKP filter drier and there oil filters will take the moisture out of the oil. I think the ingredient is activated alumni? But I also agree the best way is to change oil, then you know where you are starting from.

Cheers.

taz24
31-03-2007, 02:35 PM
Taz, Maybe it was just a sales pitch but, Alco claims that there EKP filter drier and there oil filters will take the moisture out of the oil. I think the ingredient is activated alumni? But I also agree the best way is to change oil, then you know where you are starting from.

Cheers.


I've never realy paid attention to what the chemical composition is of the new driers we use (spose I should:) ).
I do know that the moisture is bound into the dryer and cannot be released again (unlike sylica gel).
Activated alumini is used in compressed breathing air production, So if its good enough for us then it should be good enough for the fridge eh?:D.

taz.

lana
31-03-2007, 04:18 PM
410-A is an azitope refrigerant wich is a blend.


Hi there,
Just to correct :

R410A is a zeotropic blend and NOT azeotropic. It has glide of 0.2°C so you can say it is near-aezotropic.
The refrigerant code for Zeotropic blends starts with 4 but for azeotropic blends starts with 5 , like R502,....

Cheers:)