Low Cooling of Ice Cream Freezer Commercial

[kamrannasir]

Dear Friends:I am facing problem of low temperature attain in ice cream freezers(-26C), the top five coils of evaporator do cooling while the below 8 did not as the throw is also at the top. Freezer is charged with R 404a with Danfoss compressor, capillary tube and 1/6 condenser, fan cooled.Any idea how can I troubleshoot the problem.regards:

[ATR]

You talking about a 1/6 HP compressor right? This is a little reach in type unit? Is it a chest or stand up? What exactly do you have here?

[1mikeefc1]

It sounds short of gas but without any more info its shooting in the dark mate.

[drewynp]

What's your superheat? Cap tube system not getting enough refrigerant to satisfy the evap? Sounds pretty cut and dry to me.

[kamrannasir]

Yes, that is a chest freezer...

[kamrannasir]

What is the best method to identify the quantity of refrigerant, I mean, is that sufficient or not?

[1mikeefc1]

Putting your gauges on the compressor and checking gas charge is correct would be the best method.

[The MG Pony]

? Sounds low on charge, first step is to find where did the rest of the charge go! If it is really old then just slow bleed and probably safe to suck it down and recharge via the labled weight, if there is no lable any more, add say 2 or 3 ounces and let it run, watch the return gas temp (Sensible) till it is cool (add bit of gas if needed till it is cool for the compressors sake!), let it run down to operating temp, or as close as you can get it, then slowely add refrigerent till you get the super heat to about 20k let it keep running to it's lowest Tstat seting once it is opperating at it's design temp check and adjust SH no lower then 15K.