Rack Systems in Low Ambient Conditions

[Fridge Repairer]

Bottom line is don't mess with the A8 A9 valve unless you have fans cycling on and off on your condenser because your just waisting your customers time. Make sure you have a good receiver level and you will sleep fine all night long! And if you don't have a good level LEAK TEST.

[Dowadudda]

Well to be honest, none of us knows it all - except for one guy.........and he's not here today. .........

[Dowadudda]

Bottom line is don't mess with the A8 A9 valve unless you have fans cycling on and off on your condenser because your just waisting your customers time. Make sure you have a good receiver level and you will sleep fine all night long! And if you don't have a good level LEAK TEST.

okay. Listen please. You can easily, quickly and accurately set low ambient valves in higher ambient conditions. would you like to know how?

[Fridge Repairer]

Nope...but maybe others will like to know.

[markettech]

okay. Listen please. You can easily, quickly and accurately set low ambient valves in higher ambient conditions. would you like to know how?

Let's have it. What say you?

[Phase Loss]

okay. Listen please. You can easily, quickly and accurately set low ambient valves in higher ambient conditions. would you like to know how?

Fill the top of the condenser with ice cubes?

[markettech]

Fill the top of the condenser with ice cubes?

You'd have to flip the condenser blades and reverse the fan rotation in order for that to work.

[markettech]

PL...........you know if many D's has a simple/easy answer it means we can expect about 3 full pages of single spaced text, right?

[Dowadudda]

Lets give me hypothetical.

I want my minimum receiver pressure at 55SCT/R404A=115PSI. I want my dropleg 20 PSI Above that at 125 PSI, so at 60 SCT. This is my desired settings.

Since the discussion is about if the ambient is higher so that 60 SCT is unattainable normally here is what I was taught, what I would do, have done and it works.

1. valve off the receiver pressure regulator so it does not influence. Whether is an ORD or OPR.
2. Force all the condenser fans on.
3. reduce head by turning off pumps.

If the head psi is still above the target 60 SCT, let's just say it is at 70 SCT / 150 PSI at this point and I have done nothing yet. No problem.

4. Turn clockwise (in to raise pressure) the holdback in 1/4 turn /5 minute increments till you reach a pressure it will control at above the current pressure of 70 SCT.

What your doing is making the valve to holdback at the higher sct. The higher the ambient, the higher we need to find the controlling pressure in current conditions. I am using this as an example.

5. You had no idea before you started where the setting was at. But you counted how many 1/4 turns Clockwise to get it to control at the 70 SCT. So. Simple math. Subtract the difference of the current head psi which is 150, from the desired, which is 125 or rather 60 degrees SCT.

That difference is 25 PSI.

6. Divide 25, by 17. (17 is the available 1/4 turns in a typical parker holdback valve).

7. 25/17. That equals about 1.47 or so. Round off. 1.5 turns. So basically turn the valve adjustment 1.5 1/4 turns counterclockwise.

8. For the reciever ORD. Just isolate drop leg now, let the receiver pressure fall below 115, open that one till you get feed.

Thats it. It works. I have done it. I thought when this idea was first presented to me it was nuts. I went out and I proved it to myself. It works, I have went back in cooler weather to check on and it was close enough that I did not feel it was needing to be "tweaked".

[Dowadudda]

Now.

[Dowadudda]

You can do all that. But. A sprinkler works too.

[Phase Loss]

Not only have you wasted your time & your customers time...you have now wasted MY TIME TOO! and I'm pizzed!













Really tho, thank's for the explanation.

[Dowadudda]

Mathew, quit being a smart a$$ cause I know you knew this.