Manitowoc Ice MARINE MODEL S1800 - Manual (Page 86)

Refrigeration System Section 7
7-20
Part Number 80-1634-3
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.
• Regular cube production derate is 7%
• 50Hz production derate is 7%
• 50Hz regular cube total production derate is 14%
S1800 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 8.5-9.4 9.2-10.1 10.7-11.8
.75-2.00
80/26.7 8.5-9.4 9.3-10.3 10.9-12.0
90/32.2 8.6-9.4 9.4-10.4 11.1-12.2
100/37.8 8.7-9.6 9.6-10.5 11.2-12.3
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 1870 1750 1530
80/26.7 1870 1730 1510
90/32.2 1860 1710 1490
100/37.8 1830 1690 1470
Based on average ice slab weight of 13- 14.125 lb
Condenser
Water
Consumption
Air Temperature / Water Temperature °F
77/59 90/70 110/90
Gal / per
100 lbs of ice
95 155 510
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 40-24 140-160 60-80
70/21.1 225-275 45-26 155-175 60-85
80/26.7 230-295 45-28 160-180 70-90
90/32.2 255-320 46-29 170-195 80-100
100/37.8 290-360 48-30 190-215 95-115
110/43.3 325-400 49-30 225-250 110-130
Suction pressure drops gradually throughout the freeze cycle