Hoshizaki KMD-270AWA Service Manual page 20

j) Harvest Completion Detection Control (S2 dip switch 4)
Do not adjust. This must be left in the factory default position or the unit will not operate
properly.
It is activated on the KMD-270 series.
When activated, this control determines whether ice remains on the evaporator at the end of
a harvest cycle and at the beginning of a freeze cycle. If ice drops and activates the bin
control switch in the last 10 seconds of a harvest cycle, the control determines that ice still
remains on the evaporator and extends the harvest cycle for 30 seconds. If the bin control
switch is activated at the beginning of a freeze cycle, the control determines that ice still
remains on the evaporator and starts a harvest cycle after the minimum freeze cycle time
has passed.
S2 Dip Switch Setting
No. 4
OFF
ON
k) Overfreeze Detection Control (S2 dip switch 5)
Do not adjust. This must be left in the factory default position or the unit will not operate
properly.
It is activated on the KMD-270 series.
When activated, the thermistor detects the temperature of the evaporator outlet to find
overfreeze in a harvest cycle and at the beginning of a freeze cycle. If the difference
between the maximum temperature after the water saver timer starts counting and the
temperature at the end of a harvest cycle is 4K or more and if the temperature at the end of
a harvest cycle is 48°F (9°C) or less, the harvest cycle is extended for 30 seconds. If the
difference between the temperature at the beginning of a freeze cycle and the minimum
temperature after 30 seconds in the freeze cycle is 2.5K or more and less than 3.5K, the
next harvest cycle is extended for 30 seconds. If the above conditions occur in succession,
the number of occurrence times 30 seconds will be added to the harvest cycle time. If the
above temperature difference is 3.5K or more, the freeze cycle ends after the minimum
freeze cycle time and a harvest cycle starts.
S2 Dip Switch Setting
No. 5
OFF
ON
l) Anti-Slush Control (S2 dip switch 6) [Program Ver. 3.1]
Do not adjust. This must be left in the factory default position or the unit will not operate
properly.
It is activated on the KMD-270 series.
When activated (Ver. 2.0), the thermistor located on the suction line checks for a 50°F
(10°C) temperature as the evaporator cools. When 50°F (10°C) is reached, a 3.9 kΩ signal
causes the control board to de-energize the pump motor for 10 seconds and energize it for
50 seconds repeatedly. When 34°F (1°C) is reached, a 5.9 kΩ signal causes the control
board to de-energize the pump motor for 10 seconds, energize it for 50 seconds,
de-energize it again for 10 seconds, then energize it continuously.
Harvest Completion
Detection Control
Deactivated
Activated
Overfreeze Detection
Control
Deactivated
Activated
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