Selected Refrigeration Components - Scotsman UC2024 Series Service Manual

UC2024 and UC2724 Service Manual

Selected Refrigeration Components

Thermostatic expansion valve
The thermostatic expansion valve, or TXV, is the
metering device for the refrigeration system.
Superheat numbers are not listed because it
changes with heat load and with the modulation of
the valve.
Hot gas valve
The hot gas valve is located between the discharge
line and the evaporator inlet. It is only open during
harvest and for a short time during compressor
start. It is a ported valve, meaning that it restricts
the amount of refrigerant gas that can flow thru
it, protecting the compressor from excessive
refrigerant.
Compressor
The hermetic compressor is used to circulate
refrigerant throughout the entire system. It
compresses the low pressure refrigerant vapor
causing its temperature to rise and become high
pressure hot vapor (hot gas) which is then released
through the discharge valve.
Condenser, water cooled.
Heat from the ice making process is discharged into
water flowing next to the refrigerant path. Discharge
pressure is maintained by a water regulating valve.
Condenser, air cooled.
Heat from the ice making process is discharged into air
flowing thru a fin and tube assembly. The tubing is the
refrigerant path. An electric fan provides the air flow.
Access valves are at the front of the cabinet.
Evaporator
The evaporator is mounted above the ice storage bin,
and ice that forms on it is released during harvest and
falls by gravity into that bin. The refrigerant path is a
serpentine tube attached to the pan and grid.
Cube sizes are (inches):
Small cube: 7/8 high × 3/4 deep × 1/2 wide
Medium cube: 7/8 high × 3/4 deep × 7/8 wide
Pressure controls
Air cooled models have two pressure controls, a high
pressure cut out and a fan motor cycling switch. High
pressure switch cut out at 400 PSIG, automatic cut in at
300 PSIG. Fan switch cut in is at 150 PSIG and cut out
is at 100 PSIG. Water cooled models have one pressure
control, a high pressure cut out.
November 2019
Page 19