CME1356R and CME1656R
Technicians Only: Harvest Cycle Sequence & Other Notes
Harvest
The Purge Valve will be open for 74 seconds.
The water pump shuts off, it will restart before 74 seconds, the restart time is based on the Purge Level Setting.
The pump restarts and pumps water out of the reservoir until the purge valve closes.
The inlet water valve will stay on for about 30 seconds to add enough water to assist with harvest.
The Hot Gas Valve will be open for the entire length of the Harvest Cycle.
The Harvest Bypass Valve will be open for a few seconds at the beginning of the Harvest Cycle.
During the Harvest Cycle, ice will be falling from the evaporators and between the ice sensor’s electric eyes. The AutoIQ Controller monitors the ice falling and uses that information to determine the next harvest cycle length.
The first Harvest after a restart will take about 6 minutes to establish a base line, then the time it took to release that ice is used to determine the next harvest cycle’s length.
The maximum harvest time is 14 minutes.
If no cubes fall (or are sensed) by the end of the Maximum Harvest Time, the machine senses a Refrigeration error. If the next cycle also produces a Refrigeration error, the machine will shut down.
Note: The last Harvest cycle before shutting off on Bin Full will be about 6 minutes long.
Note: The machine will not restart for 4 minutes after switching off on Bin Full, unless the Freeze button is pressed.
Bin Full: The controller will switch on the compressor for 30 seconds after 12 hours of off time to keep refrigerant out of the compressor oil.
Continuous Run Time
A unit that operates 24 hours a day 7 days a week is too small for the user’s needs. To maintain harvest integrity, the controller will extend the harvest time to 6 minutes every 15th consecutive harvest cycle.
Bin Thermostat (for those units so equipped):
In normal ambients the thermostat will react to ice on the bulb in a few seconds. Reaction after removal will take about a minute under normal conditions, and longer in colder rooms.
Stacked Units:
If the bottom unit is in harvest and receives a signal from the top unit that it is also in Harvest, the bottom unit will stay in harvest for about 6 minutes.
If the bottom unit is shut off, but its controller still has power, the top unit may continue to operate. If the bottom unit’s power is shut off, the top unit will shut down on bin full at the end of the next cycle. If the top unit’s power is shut off, it does not impact the bottom unit.
An error shut down on one unit does not affect the other.
Either one may be switched off at the controller without impacting the other.
Diagnostic Light Code Table
If a Diagnostic | Water Light | Refrigeration |
Light |
| Light |
|
|
|
Blinks once | Water pump | Very long ice |
and repeats | will not start | harvest |
|
|
|
Blinks twice | Lack of water | No harvest of |
and repeats | fill | ice |
|
|
|
Blinks three | not used | High Discharge |
times and |
| Temperature |
repeats |
|
|
|
|
|
Is ON all the | Water valve | Check for low |
time | leaking thru | discharge |
| rapidly | temperature or |
|
| long freeze |
|
| cycle |
|
|
|
Both ON all the | Check for thermistor set | |
time | unplugged or failed | |
|
|
|
|
|
|
May 2001
Page 25
