Manitowoc Indigo Series Technician's Handbook page 266

Diagnostics
FREEZE CYCLE - REMOTE CONDENSER &
QUIETQUBE® REMOTE CONDENSING UNIT
1. Determine if the coil is clean.
2. Determine the air temperature entering the
condenser.
3. Determine if the head pressure is high or low in
relationship to the outside temperature. (Refer to
the proper "Cycle Times/24-Hour Ice Production/
Refrigerant Pressure Charts" page 307).
4. Determine the temperature of the liquid line
entering the receiver by feeling it. This line is
normally warm; "body temperature."
5. Using the information gathered, refer to the chart.
A head pressure control valve that will not
NOTE:
bypass, will function properly with condenser air
temperatures of approximately 70°F (21°C) or above.
When the temperature drops below 70°F (21°C), the
head pressure control valve fails to bypass and the ice
machine malfunctions. Lower ambient conditions can
be simulated by rinsing the condenser with cool water
during the freeze cycle.
Condition
Discharge Pressure - High
Liquid Line Temperature -
Discharge Pressure - Low
Liquid Line Temperature -
Cold
Discharge Pressure - Low
Liquid Line Temperature -
266
Hot
Hot
Probable
Cause
Valve stuck in
bypass
Valve not
bypassing
Ice Machine
Low on
Charge
Part Number Preliminary 6/11
Corrective
Measure
Replace
valve
Replace
valve
Refrigerant
Charge
Verification