Manitowoc QD0202A, Service Manual

Page: 116 / 175

Refrigeration System Section 7
7-4
Part No. 80-1100-3
Figure 7-4. Remote Harvest Cycle (Models Q450/Q600/Q800/Q1000)
Harvest Cycle Refrigeration Sequence
Hot gas flows through the energized harvest valve,
heating the evaporator. The harvest valve is sized to
allow the proper amount of hot gas into the evaporator.
This specific harvest valve sizing, along with the harvest
pressure regulating (H.P.R.) system, assures proper
heat transfer, without the hot gas condensing to liquid
and slugging the compressor.
The harvest pressure regulating (H.P.R.) valve helps
maintain the suction pressure during the harvest cycle.
(See “H.P.R. System” on
Page 7-27 .)
HEAT
EXCHANGER
EVAPORATOR
SOLENOID
LINE
LIQUID
CHECK VALVE
SERVICE
RECEIVER
CONDENSER
REMOTE
COMPRESSOR
RECEIVER
EXPANSION VALVE
HARVEST SOLENOID VALVE
VALVE
HARVEST PRESSURE
REGULATING VALVE
H.P.R. SOLENOID
VALVE
VALVE
CHECK VALVE
DRIER
STRAINER
HEAD
PRESSURE
CONTROL
VALVE
B
R
C
HIGH PRESSURE VAPOR HIGH PRESSURE LIQUID LOW PRESSURE LIQUID LOW PRESSURE VAPOR
SV1567