Hi, had a service call to a J&E Hall Fusion 0300-b2-m-3 Condensing unit for a walk in freezer running on R404a at a set temperature of -20 Degrees C. The unit seems to be getting to around -13/-14 Degrees C and sitting at that, the suction pressures are at around 20psi and Discharge is up and down between around 160-180 (fluctuating with fan speed). I took temperature readings at the suction valve which were at -9 Degrees C and at the expansion valve bulb which were -15 degrees, am i correct in thinking this is quite a large drop considering everything is well insulated? My first thoughts were that the suction was a tad low and discharge a tad high and perhaps the expansion valve needs adjusting. In the manual is says superheat 10k and sub cooling 0k. With the unit being set at -20 does this mean the return at the Evaporator should be coming back at -10 Degrees C and so the valve needs adjusting to allow more refrigerant through? The system runs with a full sight glass and seems to function correctly apart from stalling at -13/-14, apologies if this seems like a dumb question as this is not something i have encountered before or the type of unit i usually work on (mainly air con)

Thanks in advance.