Manitowoc QuietQube SD0672C Technician's Handbook page 162

Harvest Valve
The harvest valve is an electrically operated valve that
opens when energized, and closes when de-
energized.
NORMAL OPERATION
The valve is de-energized (closed) during the Freeze
cycle and energized (open) during the Harvest cycle.
The valve is positioned between the receiver and the
evaporator and performs two functions:
1. Prevents refrigerant from entering the evaporator
during the Freeze cycle.
The harvest valve is not used during the Freeze
cycle. The harvest valve is de-energized (closed)
preventing refrigerant flow from the receiver into
the evaporator.
2. Allows refrigerant vapor to enter the evaporator in
the Harvest cycle.
During the Harvest cycle, the harvest valve is
energized (open), allowing refrigerant gas from
the top of the receiver to flow into the evaporator.
The refrigerant changes state (from a vapor to a
liquid) and gives up latent heat. This heat is
absorbed by the evaporator and allows release of
the ice slab. In general, Harvest cycle suction
pressure rises, then stabilizes in the range of
65-125 psig (448-861 kPa).
Exact pressures vary according to ambient
temperature and ice machine model. Harvest
pressures can be found in the "Cycle Time/
24-Hour Ice Production/ Refrigerant Pressure
Charts" in this book.
162 Part Number 80-1505-3 6/11