Hoshizaki KM-901MWH - Manual (Page 21)

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(5) Harvest Cycle
Same as the initial harvest cycle. See "II.B.1.a)(2) Initial Harvest Cycle."
Note: Unit continues to cycle until TBC is satisfied or power is turned off. The unit
always restarts at the 1-minute fill cycle.
(6) Shutdown
When ice contacts the thermostatic bulb (TBC switch open), TBC shuts down the
unit within 10 seconds. TBC is factory set, and generally no adjustment is required.
However, adjustment may be needed in some conditions, particularly at higher
altitude locations.
CAUTION! Do not adjust S4 dip switch 7 out of the factory
default position on this model. This dip switch must be left in the factory
default position or this unit will not operate correctly.
Legend: CB–control board; Comp–compressor; FM–fan motor;
FMR–fan motor-remote; F/S–float switch; HGV–hot gas valve; LLV–liquid line
valve; PM–pump motor; TBC–thermostatic bin control; WV–inlet water valve
b) "G" Control Board: Auxiliary Code U-1 and Later
The steps in the sequence are as outlined below. When power is supplied, CB red
"POWER OK" LED and green "BC CLOSED" LED come on. There is a 5-second delay
before startup. Note that the order of the component LEDs from the outer edge of CB is
1, 4, 3, 2.
(1) 1-Minute Fill Cycle
LED 4 is on. WV energizes and the 1-minute fill cycle begins. After 1 minute, CB
checks for a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV remains
energized through additional 1-minute fill cycles until water fills the tank and closes
F/S. This serves as a low water safety to protect PM.
(2) Initial Harvest Cycle
LEDs 1, 4, and 2 are on. WV remains energized, Comp, FMR, HGV energize. CB
monitors the warming of the evaporator via the thermistor located on the suction
line. When the thermistor reaches 48°F (9°C), CB reads a 3.9 kΩ signal from the
thermistor and turns harvest termination over to the harvest timer (S4 dip switch 1 &
2). The harvest timer has settings of 60, 90, 120, and 180 seconds. For details, see
"II.C.3.b) Harvest Timer (S4 dip switch 1 & 2)." WV is energized during harvest for a
maximum of 6 minutes or the length of harvest minus 0 or 50 seconds (harvest pump
timer (S4 dip switch 7)), whichever is shorter.
CAUTION! Do not adjust S4 dip
switch 7 out of the factory default position on this model. This dip switch must
be left in the factory default position or this unit will not operate correctly. For
details, see "II.C.3.e) Bin Control Selector/Harvest Pump Timer (S4 dip switch 7)."
LED 4 goes off when WV de-energizes. LED 3 comes on and PM energizes and runs
for the last 0 or 50 seconds of harvest depending on S4 dip switch 7 setting. When
the harvest timer expires, the harvest cycle is complete. CB checks the position of
F/S and proceeds to the freeze cycle if it is closed or calls for a 1-minute fill cycle
if it is open. The minimum total time allowed by CB for a complete harvest cycle is
2 minutes.