Hi

Hoping someone can help me with a problem I'm having with a display chiller that has been converted for R22 to R404a. (Fixed charged, capilary line)

Unit was running but not cooling, traced to a leak in the scharder service valve on the compressor. Reclaimed remaining gas, replaced filter/dryer, pressure tested and vac-ed down.
The name plate on the chillers says 500g of r22, so i recharged with just under 450g of r404.

Heres where the problems started, the case starts to cool and the suction pressure sits around 7 psi. Straight away there is frosting on the evapourator pipes where the capilary tube enters, and after half a day there is heavy frosting over 1/3 of the evapourator (fans are running as should) and the temp starts to climb.

Apprehensive to add any more refrigerant as I don't want to damage the compressor, but I'm scrating my head at what to do next??

Any help is much appreciated

Shaun