Service manual

Section 7 . Refrigeration System
Part Number 80-1558-3 7-19
Cycle Time/24 Hour Ice Production/
Refrigerant Pressure Charts
These charts are used as guidelines to verify correct ice
machine operation.
Accurate collection of data is essential to obtain the
correct diagnosis.
• Refer to “OPERATIONAL ANALYSIS TABLE” for the
list of data that must be collected for refrigeration
diagnostics. This list includes: before beginning
service, ice production check, installation/visual
inspection, water system checklist, ice formation
pattern, safety limits, comparing evaporator inlet/
outlet temperatures, discharge and suction pressure
analysis.
• Ice production checks that are within 10% of the
chart are considered normal. This is due to variances
in water and air temperature. Actual temperatures
will seldom match the chart exactly.
• Zero out manifold gauge set before obtaining
pressure readings to avoid misdiagnosis.
• Discharge and suction pressure are highest at the
beginning of the cycle. Suction pressure will drop
throughout the cycle. Verify the pressures are within
the range indicated.
• Record beginning of freeze cycle suction pressure
one minute after water pump energizes.
• 50Hz production derate is 7%
S0850M SERIES
Self-Contained Water-Cooled
NOTE: These characteristics may vary depending on
operating conditions.
Cycle Times
Freeze Time + Harvest Time = Total Cycle Time
24 Hour Ice Production
Operating Pressures
Air Temp.
Around Ice
Machine
°F/°C
Freeze Time
Harvest
Time
Water Temperature °F/°C
50/10.0 70/21.1 90/32.2
70/21.1 7.9-9.1 8.7-10.1 9.8-11.3
1-2.5
80/26.7 8.0-9.3 8.9-10.2 10.0-11.5
90/32.2 8.1-9.4 9.0-10.3 10.2-11.7
100/37.8 8.2-9.5 9.1-10.5 10.3-11.9
Times in minutes
Air Temp.
Around Ice
Machine
°F/°C
Water Temperature °F/°C
50/10.0 70/21.1 90/32.2
70/21.1 880 810 730
80/26.7 870 800 720
90/32.2 860 790 710
100/37.8 850 780 700
Based on average ice slab weight of 5.75- 6.50lb
Regular cube derate is 7%
Condenser
Water
Consumption
90/32.2 Air Temperature
Around Ice Machine
Water Temperature °F/°C
50/10.0 70/21.1 90/32.2
Gal/24 hours 690 1420 5200
Water regulating valve set to maintain 240 PSIG discharge pressure
Air Temp.
Around Ice
Machine
°F/°C
Freeze Cycle Harvest Cycle
Discharge
Pressure
PSIG
Suction
Pressure
PSIG
Discharge
Pressure
PSIG
Suction
Pressure
PSIG
50/10.0
225-235 46-28 150-160 75-90
70/21.1 225-235 46-28 150-160 75-90
80/26.7 225-240 50-30 155-175 80-95
90/32.2 230-270 60-30 155-185 85-105
100/37.8 240-275 60-30 165-185 90-110
110/43.3 245-280 60-30 175-190 95-115
Suction pressure drops gradually throughout the freeze cycle