R-410-A

[roosterman]

I've been in TX[rio grande valley] most of time there r-22 is still very commonly used in most new installs,im in MICH now what should the "normal operateing p.s.i' be on r-410-a s central a/c system be,for low and high side's,175low,375high?????

[airconman]

what temp outside are ya dealing with?
where did ya get these pressures? out of your head or off a unit?

[Edited by airconman on 01-31-2005 at 10:47 AM]

[roosterman]

say an outdoor are temp of 90deg F

[roosterman]

say an outdoor are temp of 90deg F,just got temp off the top of my head

[airconman]

ok low side sounds a little high and the high is a little low...

[ct2]

willie my boy.
is this the first time using r-410-a? you know you have to consider the altitude difference between Mich and texas.

You did say mich like in Michigan right? because it mite be a few more days untill you get 90 degrees in michigan, now Mexico could be 90 degrees but their at a lower altitude than texas.

BTW you are going to hurt yourself and anyone that is near by if you continue with this installation, so this time you may want to think about finding someone with a 410a cert before you blow that unit and anything that is attached to it - up

[roosterman]

whta should the correct psi be for r-410-a with a ambient temp of 90 deg,i do know r-410-a is very,very absobent of moistuir,so i think nitrogen after a coil removel and a doubel evac,should keep the system moistuer free[new dreier's of course,high & low]what should the working psi be for a 90 deg day be

[docholiday]

The saturation temperatures are the same as R-22. Convert the pressures from a PT chart.
You cant troublshoot or evaluate any system by pressures alone.

[Wild Leg]

Originally posted by ct2
willie my boy.
is this the first time using r-410-a? you know you have to consider the altitude difference between Mich and texas.

You did say mich like in Michigan right? because it mite be a few more days untill you get 90 degrees in michigan, now Mexico could be 90 degrees but their at a lower altitude than texas.

BTW you are going to hurt yourself and anyone that is near by if you continue with this installation, so this time you may want to think about finding someone with a 410a cert before you blow that unit and anything that is attached to it - up

Did you mean latitude instead of altitude?

Altitude is how far from the surface of the earth toward space. Detroit is 581 feet above sea level. The Rio Grande valley is at least sea level, with some parts above 5000 ft.

LATITUDE is how far north/south.

[roosterman]

i couldnt have said it better my self bwal2,i realy think some guy's look realy bad when they try to make them self's look real smart[duh]

[Wild Leg]

Originally posted by williesanchez69
i couldnt have said it better my self bwal2,i realy think some guy's look realy bad when they try to make them self's look real smart[duh]

Let's not beat him up too badly.
He's at least willing to take a stab at it. :D

You really do need to take a strong look at temperatures, instead of pressures.
Pressures are chosen strictly based on the need for a certain temperature.
Whatever that temperature is for r-22 will be the same for 410a, 134a, 404a, 717, and r-whatever comes along that hasn't been thought of yet.

You DO know why a particular pair of numbers is acceptable for r-22, don't you?

Look into getting 410a certified by the manufacturer of the equipment you service.
If you are not a servicing dealer, or work for one, try the ESCO version.
It beats the heck out of nothing.
It won't hurt, and it is not expensive.

Using 410a requires nothing more than good basic refrigeration skills, that you should already be practicing.

Don't be afraid to learn.
Smart pays more. :D



[Edited by bwal2 on 02-02-2005 at 12:37 PM]

[filterchanger]

superheat or subcooling, what do you mean "what should the pressure be when its 90 out". What are your temps and humidity levels in the house? Altitude, Latitude, what the heck does that matter?

[mdman]

Why does anybody reference pressure for any refrigerant, ever?

It's the saturation temps that are relevant to heat exchange and refrigerant condition...super-heat, sub-cooling, ATD (a.k.a. split)! I have never thought in terms of pressure unless computing absolute compression ratio.

I guess that's just what happens when you learn how it works before you start playing with gauges.

md

[jt47]

I have a 410 R (R = remington)
multi-purpose ...has high pressure & superheat!!

[Edited by jt47 on 02-01-2005 at 10:13 PM]

[mdman]

Originally posted by jt47
I have a 410 R (R = remington)

for seek & trap?

[mdman]

It's tough to break 50 with a 410 gauge.

[airconman]

ok off top of my head on 90 degree day you could be easily seeing 425 lb to 500 depending on dirt in the coil area on high side. if outdoor fan quits and high pressure switch fails you could be looking at 900.

[docholiday]

...and internal overload fails and internal releif fails, and... I dont think you'll see 900, nice scare tactic though. How many times have you seen R-22 at 580 PSIG?

[Edited by docholiday on 02-03-2005 at 08:42 AM]

[airconman]

well saw one that topped out my gauges..... took out 8 1/2 lbs of 22 and the pressures came down to normal. This guy called back the company that just put in an extra 3 lbs the day before and they gladly gave his money back for the R 22.. but still charged for the service call.... And no I aint not never seen 900 lbs... but the last class I went to said it was possible, so nahhhhhhhhh

[docholiday]

Lol

well the saturation temperature would have to be... nearly 190. I cant even find a chart that goes that high...

You are right, once you go to solid liquid you can go into hydraulics but heck, you can get 10,000 pounds of pressure out of R-22 or 4-10 at that when they go into hydraulic pressures (water too).

All I am saying is, short of hydraulics, you are not going to see 900 psig when there is any vapor present. And if it were heading that way, the inernal relief of the compressor would open long before that.

[Shophound]

I'm certain superheat and subcooling readings are just as valid with R 410A systems as they are with R-22 or any other refrigerant.

Pressures are helpful, but only tell part of the story. Saturated vapor and saturated condensing temperatures, along with corresponding superheat or subcooling, go a lot farther than pressures alone.

[airconman]

I don't care if I go up to a 1940 unit I'm having a chart in my pocket.... only way to fly....and I just love tellin people they have to much refrigerant in their system.. they look at me like I'm crazy..... take out a lb or so and they are totally amazed that they put up with their unit so long and had no idea how really well it can work...... bottom line is after that, you have a customer for life.

[coldspot]

Originally posted by mdman
Why does anybody reference pressure for any refrigerant, ever?

It's the saturation temps that are relevant to heat exchange and refrigerant condition...super-heat, sub-cooling, ATD (a.k.a. split)! I have never thought in terms of pressure unless computing absolute compression ratio.

I guess that's just what happens when you learn how it works before you start playing with gauges.

md " What He SAID"! doesnt matter where you go or where you are , read the pressure temp chart on you guages or your charts and relate them to the ambient and the, delta T