Help!

[lurgi]

Having massive problems at a local supermarket-does anyone know the correct refrigerant level for the following system:

low temp rack, screw compressers, Tyler-Mod.vrp140l-40.

r404a. problem is everyone I work with has a different answer-at the moment there are no balls floating in a vertical receiver, and the sight glass is clear, no flashing.

the evap coils in the freezers are frosting up heavily, hot gas defrost works, but not enough to cler the coils.

Does it sound like I'm too low on refrigerant?

be really grateful for anyone's help.

thanks.

[codgy]

add the gas, balls must float

[condenseddave]

Originally posted by codgy
add the gas, balls must float

Not if that is a surge tank. Is this a surge tank, or a real reciever with a surge bypass?

If you're not flashing, what is the problem?
Low liquid level isn't going to cause case ice-ups. Is your head pressure OK? Is the defrost differential valve set and working properly? Is the defrost time NORMALLY sufficient to clear the coils, or has this been an ongoing problem? Is the terminating temp too low?

If you're not flashing at your furhtest valve, (and you are NOT if the coils are icing up...) the least of your problems is an empty reciever.

[lurgi]

as far as i know it's a real receiver, and i've had coils ice up before at different stores due to low refrigerant level. I'm just kinda trying to get the store ru nnin g properly before i lose my job! doesn't say it's an envirogaurd unit, so i'm gonna assume that it's a normal system. i don't know the history of the store, so i'm stuck there as well.

[icemeister]

Originally posted by lurgi
.......the evap coils in the freezers are frosting up heavily, hot gas defrost works, but not enough to clear the coils.

Like Dave said.....if the evaporator is iced up, it ain't the freon. I'd say you best bet is to thoroughly study the defrost system and understand how it's supposed to work.

Are all of the low temp evaporators iced up? If so I suspect that something common to all like the defrost differential pressure regulator isn't controlling.

[condenseddave]

Originally posted by lurgi
as far as i know it's a real receiver, and i've had coils ice up before at different stores due to low refrigerant level.

Trust me, supermarket cases do NOT EVER ice up to the point where ice is causing the temperature to go up, because of a low liquid condition.

That was a bigass, bodfaced, not ever.

"As far as you know". Do you know the difference between the two would be my next question.

[condenseddave]

How many pieces of copper are attached to the tank, in what sizes?