R-410A acceptable loss

[HuNGRYTeCH]

I am curious at what percentage of loss of R 410A you have to condem the remaining refrigerant and put new refrigerant in the sytem. I have a 140 ton rooftop that 1 of the circuits got a fairly big leak on the suction line filter dryer shell. The circuit contains 273lbs of refrigerant fully charged, how much it has now I am not sure. The unit pumps down every time the cooling shuts off so the unit did save some refrigerant but I don't know if it is going to be ok to put back in once I take it out to recharge the unit. Can anyone point me towards so published information that address this issue?

[ascj]

I am curious at what percentage of loss of R 410A you have to condem the remaining refrigerant and put new refrigerant in the sytem. I have a 140 ton rooftop that 1 of the circuits got a fairly big leak on the suction line filter dryer shell. The circuit contains 273lbs of refrigerant fully charged, how much it has now I am not sure. The unit pumps down every time the cooling shuts off so the unit did save some refrigerant but I don't know if it is going to be ok to put back in once I take it out to recharge the unit. Can anyone point me towards so published information that address this issue?

So one circuit contains 273pounds of 410a? So let's say your 140ton unit only has two circuits, so your 70 ton circuit contains 273pounds of 410a? I would double check your numbers.

[flange]

Typically they say you can lose "up to" fifty percent of charge "up to" three times before it is a problem. google r410 and look at dupont's white sheet on it. its a judgement call, and you shuld be able to tell if you see unusual pressures or pt relationahip doesnt match.

[HuNGRYTeCH]

So one circuit contains 273pounds of 410a? So let's say your 140ton unit only has two circuits, so your 70 ton circuit contains 273pounds of 410a? I would double check your numbers.

Why do you say that? What "calculation" are you using? This isn't a basic rooftop and doesn't fit basic calculations.

[51fitter]

That does seem high. The roofpak 140s have about 30 pounds per circuit not counting the condenser. add about 6 more pounds for that.

[badbillr]

I am curious at what percentage of loss of R 410A you have to condem the remaining refrigerant and put new refrigerant in the sytem. I have a 140 ton rooftop that 1 of the circuits got a fairly big leak on the suction line filter dryer shell. The circuit contains 273lbs of refrigerant fully charged, how much it has now I am not sure. The unit pumps down every time the cooling shuts off so the unit did save some refrigerant but I don't know if it is going to be ok to put back in once I take it out to recharge the unit. Can anyone point me towards so published information that address this issue?

this is from dupont's faq section on its web site:

[HuNGRYTeCH]

This is a Trane Intellipak II. It has a high capacity evaprotive condenser (aka a cooling tower). The 273lbs of refer is the factory charge.

The 50% loss 3 times is interesting rule. I am hoping I have 135lbs left...

[heavymetaldad]

this is from dupont's faq section on its web site:

as the thumbnail states................ add as liqwid.......... soooooo............... it evaporates at different rates due to the chemical composition............. which means it leaks at different rates out of places other than liquid containing areas.
and who knows how many times it has been topped off before you got there.
make your own decision, i already have.