6
5) Normal Harvest Cycle
The water valve opens to allow water to assist the
harvest. As the evaporator warms, the thermistor
reaches 9°C. The control board receives the
thermistor signal and starts the defrost timer. The
water valve is open during harvest (defrost) for a
maximum of 6 minutes or the length of harvest,
whichever is shorter. When the defrost timer
completes its countdown, the defrost cycle is
complete and the next freeze cycle starts.
The unit continues through 3), 4) and 5) sequence
until the bin control senses ice and shuts the unit
down.
Note: If the icemaker does not start or complete
a cycle of operation, contact your nearest
Hoshizaki Distributor for guidance.
1) Is the icemaker level?
2) Is the icemaker in a site where the ambient
temperature is within +7°C to +40°C all year
around?
3) Is there at least a 15 cm. clearance around the
icemaker for maintenance or service?
4) Have all shipping tape(s), packing and cartons
been removed from the icemaker? Are the cube
guides in their correct position?
5) Have all electrical and piping connections been
made?
6) Has the power supply voltage been checked or
tested against the nameplate rating?
7) Are the water supply line shut-off valve and drain
valve installed? Has the water supply pressure
been checked to ensure a minimum of .7 bar and a
maximum of 8 bar?
Note: The icemaker may stop running when the
water supply is OFF, or if the pressure
is below .7 bar. When the proper water
pressure is reached, the icemaker
automatically starts running again.
8) Have the compressor hold-down bolts and
refrigerant lines been checked against vibration
and possible failure?
9) Has the bin control switch been checked for correct
operation?
10) Has the end user been given the instruction
manual, and instructed on how to operate the
icemaker and the importance of the recommended
periodic maintenance?
11) Has the end user been given the name and
telephone number of an authorized service agent?
The steps in the start-up/operation sequence are as
follows:
1) 1 Minute Fill Cycle
The unit always starts in the 1 minute ll cycle.
When power is applied to the unit, the water valve is
energized and the ll period begins. After 1 minute
the board checks for a closed oat switch. If the
oat switch is closed the harvest cycle begins. If
not, the unit will not start without adequate water in
the sump. This serves as a low water safety shut
off. The water valve will remain energized through
additional 1 minute cycles until sufcient water
enters the sump and the oat switch closes.
2) 1st Harvest Cycle
The compressor starts, hot gas valve opens, water
valve remains open and harvest begins. As the
evaporator warms, the thermistor located on the
suction line checks for a 9°C temperature. When
9°C is reached, the harvest is turned over to the
adjustable control board defrost timer which is
factory set for normal conditions. This adjustment
can vary the defrost timer from 1 to 3 minutes.
3) Freeze Cycle
After the timer terminates the harvest cycle, the hot
gas and water valves close, and the ice production
cycle starts. For the rst 5 minutes the controller
board will not accept a signal from the oat switch.
This 5 minute minimum freeze acts as a short cycle
protection. At the end of 5 minutes the oat switch
assumes control. As ice builds on the evaporator the
water level in the sump lowers. The freeze continues
until the oat switch opens and terminates ice
production.
4) Harvest Pump Out
When the oat switch opens and signals the
completion of the freeze cycle, the harvest
cycle begins. The hot gas valve opens and the
compressor continues to run. The drain timer starts
counting the 10/20 second pump out.
The water pump stops for 15 seconds and reverses,
taking water from the bottom of the sump 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 ows
through the small tube to power ush the oat
switch. When the drain timer stops counting, the
pump-out is complete.
Pump-out always occurs on the 1st harvest after
the initial freeze cycle. The control board allows for
adjustment for pump-out to occur every cycle, or
every 2nd, 5th or 10th cycle from this point.
