Manitowoc RNS012, Technician'S Handbook, Page: 113 / 124

Part Number STH044 10/13 105
Charts
Cycle Times/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 “Refrigeration System Diagnostics” for the
data that must be collected. This list includes:
before beginning service, ice production check,
installation/visual inspection, water system
checklist, safeguards, 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. Allow system to stabilize,
then verify the pressures are within the range
indicated.
• All pressure readings must be obtained at the ice
machine head section. Lineset length will affect
pressures at the condensing unit.
• Water temperature will affect suction and
discharge pressure - 50° water temperature will
result in pressures on the lower end of the ranges
specified. 90° water temperatures will result in
pressures on the upper end of the ranges
specified.