Hi,

I have a low temp -18 freezer room approx 2m x 4m with a 3 fan evaporator. Compressor is a Maneurop MT51HK4A that appears to be a replacement from original (given the burnout drier still in place). Freezer running on 404A and this would have been also converted over given the cond set would be 10 year old.

I have recently replaced TX with 404 Danfoss and removed suction burn out and replaced liquid drier. Cleaned cond coils. Refrigerant levels OK with clear sight but has long 20m run. With SH at factory, I am getting approx -7C air off the evap coil with frosting on suction line about 5m from compressor. Room temp more like cool room. Suction arount 100kpa and discharge around the 1500kpa mark (ambient around 30C). Opened valve a one turn and suction now at 250kpa with frosting to compressor and room now slowly getting down.

Worried about refrig flood back. Wondering if this Maneurop MT51HK4A suited to low temp freezer room and whether it incorrect replacement from original. What pressures should I be getting for a 404 freezer room? Being mainly (99%) in the Air Con field I am struggling with this one.

Hope someone can shed some light on this one.

Regards