409a meat case issue

[cleverd]

I am new to this sight and need some help. I am a first year tech so this site is great for me. I was at a job and found a leak on a meat case with 409a in it. I repaired the leak, pullled a vaccuum down to 360 microns so I know the leak is fixed. I just dont know what pressures I should be looking for on high and low side. It has about fifteen feet of line set and has a gravity cooled evap, no evap fans, one on bottom of case and one on top. What should my subcooling be? Or should I say what should evap temp be? please help, thx

[licencetochill]

Hello Mate,
What are you really asking? are you worried about your refrigerant charge? Do you have a TXV or is it capillary?

R-409A has properties and performance similar to R-12, Low side pressures are similar to those of R-12, while high side pressures will typically be 15 to 25 psi(1-1.7bar) higher

Iv personally never seen a meat case with static Evaporators, but i guess they would dry the meat out less.

If your running Static Evaps and not forced draft(fans) id get hold of a Pressure/temp chart for R12 and relate what pressures you are running to what it says on the chart.
Id expect your suction pressure to be pretty low, possibly around 10-15 psi(0.7-1 bar).

[littleyapper]

spot on licencetochill or if you are very much a newbeeeee r12 and r134a very similar

[Brian_UK]

You say that the leak is fixed because you did a vacuum test.

OK so it held at a pressure of +14psi, did you do a pressure test as well?

[fazzamouse]

what sort of case is it,does it not have a label with make,model etc,if so it should give you a gas charge,just weigh it in and away you go.

[cleverd]

yes i put 150 lbs of nitro in system and held for an hour with no drop at all. I got it to work on saturday, and so far so good. It had a reading of 15 psi on low side which is working out great, the meat case is staying between 35-41. Thank you for the reply, i appreciate it