Hoshizaki KM-901MAH Service Manual page 22

(3) Freeze Cycle
LED 1 is on. Comp and FMR remain energized, PM, FM, and LLV energize. HGV
and WV de-energize. For the first 5 minutes, CB will not accept a signal from F/S.
This minimum 5-minute freeze time is short cycle protection for Comp. At the end of
5 minutes, F/S assumes control. As ice builds on the evaporator, the water level in
the tank lowers. The freeze cycle continues until F/S opens and terminates the cycle.
There is a 15 second delay before CB acknowledges an open F/S.
(4) Pump-Out Cycle
LEDs 1, 3, and 2 are on. LED 4 is on when S4 dip switch 3 & 4 are set to 3 off and
4 on. Comp and FMR remain energized, HGV energizes, WV energizes if S4 dip
switch 3 off and 4 on. LLV and FM de-energize. PM stops for 2 seconds then
reverses, taking water from the bottom of the tank and forcing pressure against the
check valve seat allowing water to go through the check valve and down the drain.
At the same time, water flows through the small tube to power flush F/S. When the
pump-out timer expires, the pump-out is complete.
The first pump-out occurs after the 11th freeze cycle, then every 10th cycle
thereafter. The pump-out frequency control is factory set, and generally no
adjustment is required. However, where water quality is bad and the icemaker needs
a pump-out more often, the pump-out frequency can be adjusted. The pump-out
frequency control (S4 dip switch 5 & 6) can be set to have a pump-out occur every
cycle, or every 2, 5, or 10 cycles. Timing of the first pump-out is dependent on S4
dip switch 5 & 6 settings. See the table below. For details, see "II.C.3.d) Pump-Out
Frequency Control (S4 dip switch 5 & 6)."
S4 Dip Switch Setting
No. 5
OFF
ON
OFF
ON
(5) Harvest Cycle
Same as the initial harvest cycle. See "II.B.1.b)(2) Initial Harvest Cycle."
Note: Unit continues to cycle until MBC is satisfied or power is turned off. The unit
always restarts at the 1-minute fill cycle.
"G" Control Board Settings
Pump-Out
Frequency
No. 6
OFF Every cycle
OFF Every 2 cycles
ON Every 5 cycles
ON Every 10 cycles
22
1st Pump-Out
After 2nd freeze cycle
After 3rd freeze cycle
After 6th freeze cycle
After 11th freeze cycle