Section 7 Refrigeration System
Part No. 80-1100-3 7-17
ANALYZING DISCHARGE PRESSURE
DURING FREEZE OR HARVEST CYCLE
Procedure
1. Determine the ice machine operating conditions:
Air temp. entering condenser ______
Air temp. around ice machine ______
Water temp. entering sump trough ______
2. Refer to Operating Pressure Chart for ice machine
being checked. (These charts begin on Page 7-33.)
Use the operating conditions determined in step 1 to
find the published normal discharge pressures.
Freeze Cycle _______ Harvest Cycle_______
3. Perform an actual discharge pressure check.
4. Compare the actual discharge pressure (step 3) with
the published discharge pressure (step 2).
The discharge pressure is normal when the actual
pressure falls within the published pressure range for the
ice machine’s operating conditions.
Freeze Cycle Discharge Pressure High Checklist
Freeze Cycle Discharge Pressure Low Checklist
NOTE: Do not limit your diagnosis to only the items listed in the checklists.
Freeze
Cycle PSIG
Harvest
Cycle PSIG
Beginning of Cycle __________ __________
Middle of Cycle __________ __________
End of Cycle __________ __________
Possible Cause Check/Correct
Improper installation See “Installation/Visual Inspection Checklist” on Page 7-10
Restricted condenser air flow (air-cooled models) High inlet air temperature (110°F/43.3°C max.)
Condenser discharge air recirculation
Dirty condenser filter
Dirty condenser fins
Defective fan cycling control
Defective fan motor
Restricted condenser water flow (water-cooled
models)
Low water pressure (20 psi min.)
High inlet water temperature (90°F/32.2°C max.)
Dirty condenser
Dirty/defective water regulating valve
Water regulating valve out of adjustment
Improper refrigerant charge Overcharged
Non-condensables in system
Wrong type of refrigerant
Other Non-Manitowoc components in system
High side refrigerant lines/component restricted (before mid-condenser)
Defective head pressure control valve (remote models)
Possible Cause Check/Correct
Improper installation See “Installation/Visual Inspection Checklist” on Page 7-10
Improper refrigerant charge Undercharged
Wrong type of refrigerant
Water regulating valve (water-cooled condensers) Out of adjustment
Defective
Other Non-Manitowoc components in system
Defective head pressure control valve (remote models)
Defective fan cycle control
To Next Page
Loading...
Need help?
General