Manitowoc Indigo Series, Technician'S Handbook

Page: 204 / 270

204 Part Number STH025 02/12
3. Freeze time normal?
(Refer to Cycle Times/Refrigerant Pressures/24
Hour Ice Production Charts page 225)
Shorter freeze cycles
- Refer to head pressure
control valve diagnostics page 198.
Longer freeze cycles
- Refer to water system
checklist page 132, then refer to Refrigeration
Diagnostic Procedures.
4. Harvest time is longer than normal and control
board indicates safety limit #2?
(Refer to Cycle Times/Refrigerant Pressures/24
Hour Ice Production Charts page 225)
Connect refrigeration manifold gauge set to the
access valves on the front of the ice machine.
Establish baseline by recording suction and
discharge pressure and freeze & harvest cycle
times. (Refer to “
Freeze Cycle Refrigeration
System Operational Analysis Tables
” for data
collection detail page 123).
5. Discharge line temperature is greater than 150°F
(66°C) [I0850/I1000 Air/Water Only -
140°F (60°C)] at the end of the freeze cycle? (See
Discharge Line Temperature Analysis on
page 144)
6. Freeze cycle Head Pressure is in the range
indicated in the cycle time/24 hour ice production
and operational pressure chart?
If the head pressure is low refer to head pressure
control valve diagnostics page 198.
7. Freeze cycle Suction Pressure normal?
Refer to analyzing suction pressure if suction
pressure is high or low page 138.
8. Harvest cycle suction and discharge pressures
are lower than indicated in the cycle times/
refrigerant pressures/24 hour ice production
chart?
9. Replace Harvest Pressure Regulating solenoid.