MACH2 r404a modded help

[GomerPyle]

Hey I have a modded MACH2 with r404a. Now there are ice at the outside of the compressor. Is that normal? Or should I let some gas out through the switch I have?

[Zejtan]

i think you should let some gas out yes,
the problem with the ice is, and im pretty shure that it is because of to mutsh 404. the ice builds upp because of the compressor gets liquide instead of cas in to the compressor, try to let some gas out in small amounts att the time, and DONT do it when the compressor is operating, if you do that, and the valve is on the low pressure side, you are gonna have to, as another fine young man wrote on this forum once "drive the fancy vacum pump" again.
Because yoy havent let anything out, but you let air in =)

hope you understood what i meent, not so good in englis since i left "highscool" or what you call those grades over there =)

[Chris_F]

Uh, don't you let gas out on the high side? If you open up the low side, your going to let gas in even if it's off.

[GomerPyle]

Filling in on the high side? Well the compressor is getting really cold in the front bottom where the "tube" ends into the kompressor. What shall I do`? My temps before r404a mdo was -30 idle and -20 load and now they are -29 idle and -18 load with r404a.......:( ( with a 3.0@4.0 1.80volt)

Please help me to understand the consequenses for letting more gas out!!??

[chilly1]

You are looking for about 18 to 22 degrees of superheat. superheat is the amount that the refrigerant is heated above it's saturation point. You take the temperature of the line, and the pressure. convert the temperature and subtract the actual measured temperature, this is the super heat.... superheat too low remove gas superheat too high add gas.... (this is the simple expalanation) When you remove gas do it from the high side only or you will fractionate causing (expecially with 404) a blend of gasses that will not work as well. The only way to be sure of your refrigerant composition is to evacuate the unit to 250 microns or less then add the refrigerant in liquid phase only. If you have a prometeia with an un modded cap tube charge to 4" under load this will be a good starting point.

[JCviggen]

Originally posted by Chris_F
Uh, don't you let gas out on the high side? If you open up the low side, your going to let gas in even if it's off.

pressure is equalized when everything is off, so you can let gas out from the low side when its off. If you want to let out gas during operation the fill port needs to be on the high side obviously

[water_cooler 20]

when u let the gas out of the high side when the sys is on make sure u let it up there the fill line(middle hole) on the Gauges when i was playing w/ a sys for the 1st time i opened the high side tube alittle on the flare fitting on Gauge but that line flied off and i almost got hit in the head w/ it and it let all the gas out of the sys

[GomerPyle]

Ok sorry for my lack of intelligence hehe but I dont understand all that in the midlle high and low....cause I only have one place to take out the gas, and I'm doing that when the Mach2 is turned off.

Is it correct that when there is "ICE" on the compressor + the compressor is saying a lot of strange noises I just have to take some more gas out?

Thanx in advance.

[water_cooler 20]

yes

[Redwolf]

404A is an azeotrope mixture of 125/143A/134A (44/25/4)
So there is no way your going to know what you let out if its in a gas form, with out spending alot of cash.
I don't even trust the blends in liquid form... pull out the charge and start over!!!

[FUGGER]

Good answer Redwolf, very true from my minimal experiance of adjusting a load after the charge after the hoses were removed.

One point everyone missed is if you let out gas make sure the unit is turned off and pressure has equilized. With the unit on and in a vacuum it will suck in atmosphere and ruin the R404 charge completely.

[Redwolf]

You mean for removing (ie recover/reclaim)
Ya its good to not have it running when your doing this.

I think one problem is all these questions have been answered to death.
We need a sticky that has the do's and donts, What works and what does not, How to braze and how not to, etc etc etc.
One for each would be good. Theres just to much info on the prep work in refrigeration to make them into one.

[water_cooler 20]

i don't think this broad can stand another sticky

[Marci]

We need a sticky that has the do's and donts, What works and what does not, How to braze and how not to, etc etc etc.

Cept that's what the entire content of this forum is all about... it's all there by various people.... to consolidate it all would take days, if not weeks to get it into a useable sticky... hit that search button....

[bowman1964]

yea just let out a small burst at a time.from the high side.

everyone wants to make this harder than it is.it is begining to become too hard to understand anymore.we all need to understand 99.9% of the guys that come in here are not techs.

just let out a 1 sec burst after it has set off for 30 minutes.then run again.it may take a while.but this is the best and safest way to slowly adjust the charge.without removing too much.for a normal guy without tools,just watch the suction line at the compressor,when it stops frosting right at the compressor you are proberly very close.leave it.

i do mine while running.but i have tools to do it with.and can be done qiicky without contamimating the charge,if you know what you are doing.

[GomerPyle]

yea just let out a small burst at a time.from the high side.

Thanx just what I needed. Did it a couple of times and now I have some better temps......not much -33 idle and -22 load. The frost is still there though, but not that much.

Question: Do I have to keep on letting the gas out the ALL the frost is gone (I'm not able to set any frost anymore) or only till the frost is gone from the compressor it self?
There aint frost on the compressor right now, but still on the "pipe" (sorry for my english).

[bowman1964]

well if it isnt frosting on the compressor and you dont hear any clicking nosies...leave it alone.....that will be as good as you will get with no tools.

now go have some fun.:D

when all this becomes too much work ...it isnt worth it anymore.

[FUGGER]

Or put it under more load, that will reduce the frosting too.