Manitowoc Welbilt Indigo NXT QuietQube Manual page 119

Indigo NXT Ice Machine Troubleshooting
Symptom #2:
QuietQube ® - Symptom #2 – Ice Machine has a Long Freeze Cycle
QuietQube
Single Evaporator, Single Expansion Valve
Operational Analysis 1
Ice Production Published 24 hour ice production ____________________
Calculated (actual) ice production ___________________
NOTE: The ice machine is operating properly if the ice fill pattern is normal and
ice production is within 10% of charted capacity
Installation and Water All installation and water related problems must be corrected before proceeding with chart.
System
Ice Formation Pattern
Ice formation is extremely
thin on outlet of evaporator
-or-
No ice formation on the top
of the evaporator.
Safety limits
Refer to "Analyzing Safety Stops on safety limit:
Limits" to eliminate all non- 1 or 2
refrigeration problems.
Freeze Cycle
Discharge Pressure
_______ ______ ___
1 minute Middle End If discharge pressure is High or Low refer to freeze cycle high or low discharge pressure problem checklist to
into cycle eliminate problems and/or components not listed on this table before proceeding.
Freeze Cycle
Suction Pressure If suction pressure is High or Low refer to freeze cycle high or low suction pressure problem checklist to eliminate
_______ ______ ___ Suction pressure is
High
1 minute Middle End
into cycle
Harvest Valve
Audible refrigerant flow
through valve in freeze
cycle
Suction Line
Temperature
Suction line
Attach a temperature probe temperature at the suction
on the suction line within 6" shut-off valve is greater
of the shut-off valve outlet. than
Record the low event at the 10°F (-12.2°C)
end of the freeze cycle. at the end of the freeze
cycle
Final Analysis
Enter total number of
boxes checked in each Harvest Valve Leaking
column.
Quiet Qube Refrigeration Operational Analysis Table
 Ice Machines Refrigeration Diagnostic Chart
2 3
Ice formation is extremely Ice formation normal
thin on outlet of evaporator -or-
-or- Ice formation is
No ice formation on entire extremely thin on inlet
evaporator of evaporator
-or-
No ice formation on
entire evaporator
Stops on safety limit: Stops on safety limit:
1 or 2 1 or 2
problems and/or components not listed on this table before proceeding.
Suction pressure is Suction pressure is
Low or Normal Normal or High
No audible refrigerant flow No audible refrigerant
through valve in freeze flow through valve in
cycle freeze cycle
Suction line Suction line
temperature at the suction temperature at the
shut-off valve is greater suction shut-off
than valve is
10°F (-12.2°C) less than
at the end of the freeze 10°F (-12.2°C)
cycle at the end of the
freeze cycle
Refrigerant
Low on Charge
Overcharge
-or-
-or-
TXV Starving
TXV Flooding
4
Ice formation normal
-or-
No ice formation on entire
evaporator
Stops on safety limit:
1
Suction pressure is
High
No audible refrigerant flow
through valve in freeze cycle
Suction line
temperature at the suction
shut-off valve is
greater than
10°F (-12.2°C)
at the end of the freeze cycle
Compressor
119
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