Sequence Of Operation; Service Limits; Service Limit 1 Long Freeze Cycle; Service Limit 2 Long Harvest Cycle - Manitowoc CrystalCraft Premier USE0050 Manuel D'installation, D'utilisation Et D'entretien

Operation

Sequence of Operation

Depending on ambient conditions and cold water supply
temperature, the ice making process will take approximately
15-30 minutes.
Step 1 Initial Start-Up or
Start-Up After Automatic Shut- Off:
Water Purge/Refrigeration Equalization
Before the compressor starts, the harvest valve and dump
valve will energize for 15 seconds to equalize pressure in the
refrigeration system and purge old water from the system.
Step 2 Refrigeration System Start-Up - Prechill
The compressor, condenser fan motor, liquid line solenoid
and water inlet valve energize. The prechill cycle continues
until the water trough fills (float valve opens) and the 30
second minimum prechill time expires.
Step 3 Freeze
The water pump energizes and sprays water onto the
evaporator. The water freezes on the evaporator, dropping
the water trough level until the low water float closes, ending
the freeze cycle.
Step 4 Harvest
The water pump and water inlet valve remain on for 45
seconds, then shutoff. The evaporator is warmed, allowing
the cubes to release from the evaporator and drop into the
storage bin. As the cubes drop into the bin a 60 second timer
starts. The harvest cycle ends when the 60 second timer
expires.
• When the bin is not full of ice the control will start a new
prechill cycle (step 2).
• When the bin is full of ice the control initiates step 5
automatic shutoff.
Step 5 Automatic Shut-Off
The level of ice in the storage bin controls the ice machine
shut-off. When the bin is full, ice will either contact the bin
thermistor or hold the water curtain open, which stops the
ice machine. The ice machine remains off until ice no longer
contacts the bin thermistor and/or the water curtain. The
increase in temperature will restart the ice machine (step 1).
16

Service Limits

Service limits protect the machine from major system
failures. The service LED will flash when one of the five
service limits are exceeded. When the service button is
pressed the LED will flash the corresponding number for
the fault condition. For example if service limit 2 occurs the
service light will flash twice. Only the most recent service
limit is saved to memory.

SERVICE LIMIT 1 LONG FREEZE CYCLE

The maximum freeze time is 30 minutes at which time the
control board automatically initiates a harvest cycle (step 4).

SERVICE LIMIT 2 LONG HARVEST CYCLE

The maximum harvest time is 7 minutes at which time the
control board either starts a prechill cycle (step 2) or enters
automatic shutoff (step 4).

SERVICE LIMIT 3 WATER LOSS

In the Prechill cycle (step 2) when the high and low water
level float switches do not open within 4 minutes the ice
machine stops.

SERVICE LIMIT 4 CONDENSATE PUMP FAULT

When the float switch on the condensate pump is open
or the float switch jumper is disconnected from the wire
harness the ice machine stops.

SERVICE LIMIT 5 FULL BIN FAULT

When power is on and the ice machine has remained off for
24 hours the service LED will flash.
Refer to "Troubleshooting" on page 23 for further service
limit detail.
Part Number 000016662 Rev 01 01/22
Section 3