Service manual

Section 7 Refrigeration System
Part No. 80-1206-3 7-5
Suction Accumulator Operation
Liquid refrigerant collects in the suction accumulator
during the harvest cycle and is removed during the
freeze cycle. The liquid refrigerant is returned to the
compressor through a screen and orifice in the suction
accumulator J tube. Passing the liquid through the orifice
causes a pressure drop; the liquid flashes to a vapor and
creates a refrigeration affect. It is normal to see frost on
the accumulator, suction line and compressor suction
port in the freeze cycle. The suction accumulator
empties within the first 6 minutes of the freeze cycle.
When the refrigeration affect ends (liquid refrigerant has
been removed), the suction line between the
accumulator and compressor will increase in
temperature. The suction line temperature increases 20
plus degrees 2 minutes after the liquid has been
removed. The time needed to remove the liquid
refrigerant will vary with the ambient temperature and
the length of the harvest cycle. Higher ambient
temperatures = shorter harvest cycles, faster removal of
liquid refrigerant from the accumulator and greater
suction line temperature increases.
Refrigerant Charge
Refrigerant charge on QuietQube® ice machines is very
important. Overcharged or undercharged machines will
normally fail in the harvest cycle (produces even sheets
of ice, but will not harvest).
• Undercharged ice machines run out of liquid
refrigerant in the receiver during harvest. This
increases the harvest cycle time and results in a
safety limit #2 failure.
• Overcharged ice machines sub cool the liquid
refrigerant in the receiver during the freeze cycle.
resulting in a refrigerant boil off rate in the harvest
cycle that is too low. This increases the harvest cycle
time and results in a safety limit #2 failure.
• When you are replacing refrigeration system
components, verify refrigerant charge is correct by
weighing amount recovered. Incorrect refrigerant
charge will result in component misdiagnosis.