B. sequence of operation, Sequence cycles and shutdown, A) fill cycle – Hoshizaki FD-1001MWH(-C) EN User Manual
Page 23: B) ice purge cycle, C) freeze cycle, D) drain cycle
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B. Sequence of Operation
The steps in the sequence are as outlined below. This unit utilizes a control board to
switch the components on and off as needed. When power is supplied, the power switch
is in the "ON" position, and the control switch is in the "ICE" position, CB "POWER OK"
LED comes on.
1. Sequence Cycles and Shutdown
a) Fill Cycle
"WTRIN" LED is on. WV energizes and fill cycle begins. UF/S closes and WV
de-energizes. 30-second GM delay timer starts. If UF/S remains open during fill cycle
longer than 90 seconds, WV remains energized, and a 1-beep alarm sounds.
b) Ice Purge Cycle
"GM" LED is on. 30-second GM delay timer terminates. GMR (X2 on CB), GM, GMPR,
FM/FMR energize. 5-minute ice purge timer starts; GM runs for 5 minutes to clear any
ice from the evaporator. To bypass, press the "SERVICE" button on the control board
after GM starts.
WARNING! Risk of electric shock. Care should be taken not to
touch live terminals.
Note: UF/S must be closed before GMR will energize.
c) Freeze Cycle
"COMP" and "GM" LEDs are on. 5-minute ice purge timer terminates. GMR (X2 on
CB), GM, GMPR, and FM/FMR remain energized, CR (X1 on CB) and Comp energize
(LLV and SLV energize on MLH models). As water in the evaporator cools, ice starts
forming within 4 to 6 minutes. This time frame depends on the inlet water and ambient
temperature conditions. UF/S and LF/S operate WV as needed to continue the ice
making process. This continues until BC shuts down the icemaker or power is turned off
to the unit.
d) Drain Cycle
(1) 1-in-1 Drain Cycle: DV energizes once every hour when the 1-in-1 drain cycle
is activated (S1 dip switch 4 is in the "OFF" position (factory default position)).
GMR (X2 on CB), GM, GMPR, FM/FMR, CR (X1 on CB), and Comp continue. DV
energizes for 2 seconds every hour. This setting is recommended for optimum
icemaker performance. The 1-in-1 drain cycle allows any sediment to drain from the
evaporator without interrupting the icemaking process.
(2) 1-in-12 Drain Cycle (optional): DV energizes once every 12 hours when the 1-in-12
drain cycle is activated (S1 dip switch 4 is in the on position (optional)). 12 hour
drain cycle timer terminates, CR (X1 on CB) and Comp de-energize (LLV and SLV
de-energize on MLH model), GMR (X2 on CB), GM, GMPR, and FM/FMR continue.
The 5-minute ice purge timer begins. When the 5-minute ice purge timer terminates,
GMR (X2 on CB), GM, GMPR, and FM/FMR de-energize. 10-minute DT begins, DV
energizes. After 10-minute DT terminates, 12 hour drain cycle timer starts.