Manitowoc STH042 4/16, Technician'S Handbook

Page: 78 / 146

78 Part Number STH042 4/16
Analyzing Discharge Pressure
1. Determine the ice machine operating conditions:
Air temp. entering condenser ______
Air temp. around ice machine ______
Water temp. entering sump trough ______
2. Refer to “Cycle Times, 24 Hr. Ice Production and
Refrigerant Pressure Charts” on page 127 for ice
machine being checked.
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.
Freeze Cycle
PSIG
Harvest Cycle
PSIG
Beginning of
Cycle __________ __________
Middle of
Cycle __________ __________
End of
Cycle __________ __________
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. It is normal for the
discharge pressure to be higher at the beginning of the
freeze cycle (when load is greatest), then drop through
out the freeze cycle.