Manitowoc S600M, Service Manual

Page: 75 / 103

Section 7 Refrigeration System
Part Number 80-1630-3
7-9
Safety Limit #1
Refer to previous page for safety limit operation.
Freeze time exceeds 60 minutes for 6 consecutive freeze cycles .
SAFETY LIMIT NOTES
• Because there are many possible external problems,
do not limit your diagnosis to only the items listed in
this chart.
• A continuous run of 100 harvests automatically
erases the safety limit code.
• The control board will store and indicate only one
safety limit – the last one exceeded.
• If the toggle switch is moved to the OFF position and
then back to the ICE position prior to reaching the
100-harvest point, the last safety limit exceeded will
be indicated.
• If a Safety Limit light did not flash prior to the ice
machine restarting, then the ice machine did not stop
because it exceeded a safety limit.
Possible Cause Check/Correct
Improper installation See “Installation/Visual Inspection Checklist”
Water system Low water pressure [20 psi (138 kPa) min.]
High water pressure [80 psi (552 kPa) max.]
High water temperature (90°F/32.2°C max.)
Clogged water distribution tube
Dirty/defective water fill valve
Dirty/defective water dump valve
Defective water pump
Loss of water from sump area
Electrical system Low incoming voltage
Ice thickness probe out of adjustment
Harvest cycle not initiated electrically
Contactor not energizing
Compressor electrically non-operational
Miscellaneous Restricted condenser airflow
Condenser discharge air recirculation
Dirty condenser filter
Dirty condenser
Restricted condenser water flow
Low water pressure [20 psi (138 kPa) min.]
High water temperature (90°F/32.2°C max.)
Dirty/defective water regulating valve
Water regulating valve out of adjustment
Refrigeration system Improper refrigerant charge
Non-Manitowoc components
Defective harvest valve
Defective compressor
TXV starving or flooding (check bulb mounting)
Non-condensables in refrigeration system
Plugged or restricted high side refrigerant lines or component