Hoshizaki IM-500SAA User manual

AM SERVICE TRAINING
Featuring the
IM-500SAA
80047 9/10/13

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20mm
All IM models have similar sequence of operation. This manual is designed as a
generic IM Training manual.
The Hoshizaki IM series ice machine
uses a horizontal evaporator design
which forms a square cube shape with a
small dimple.
A standard 120-volt power cord (field
supplied) provides the electrical
connection. The unit is designed to
operate on a separate 20-amp circuit.
The water supply connection is 1/2” FPT
fitting and is located at the top right side
of the unit. A minimum 1/4” water line
is required for proper operation.
The drain connection is 3/4” FPT fitting
located on the right rear of the unit. A
standard 3/4” MPT fitting can be used to
connect this drain.

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The ABS water plate sprays water up
into the evaporator cells to form the
square IM cube.
The moveable water pan assembly
includes the water plate, reservoir
pan, and pump motor assembly.
Tension springs connect two cam
arms to the water plate assembly. An
actuator motor rotates the cam arms
to raise and lower the water pan
during the ice making cycle.

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The horizontal evaporator and water
distribution system are unique to the
Hoshizaki IM series. The IM-500 makes
ice on a horizontal evaporator and uses
R-404a refrigerant.
The IM-500SSA sequence of operation
will be explained in the following pages.

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The IM-500SAA unit uses a
combination thermistor and control
board to control the sequence of
operation.
SOFT START:
When the toggle switch is placed in the
“ON” position and the bin control calls
for ice, the unit will begin in the soft
start the display will say “on” and the
hot gas valve will open after 30 seconds
the initial harvest cycle begins,(if the
reset switch is pressed during the 30 sec.
standby time the unit will skip soft start
and immediately starts operation).
Starting the unit in harvest allows the
compressor to start up in basically an
unloaded condition, greatly extending
the life of the compressor. This
operation is common among all
Hoshizaki cube icemakers.
WATER PAN OPENS/HARVEST:
During the initial harvest, the
compressor, hot gas valve and the
actuator motor starts to open, after 20
seconds the water valve will energize to
supply defrosting water for a specified
time. (The time varies depending on the
incoming water temperature above or
below 48ºF(9ºC) also in initial cycle the
water temp. is not detected and
assumed to be below 48ºF (9ºC)
resulting in a longer defrosting water
supply time.
The opening backup timer starts
counting when the water pan starts to
open if the hall IC (magnetic switch)
does not turn on within 3 min. the
display will show “EE” and the unit
stops for 60 minutes, if it reoccurs after
the unit resumes display will show “EE”
and the unit shuts down and (records as
“E3” in the error history.
Thermisto
r

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As soon as the pan starts to open the defrost
backup timer starts, if the thermistor mounted
on the evaporator does not reach the defrost
completion temperature before the timer times
out at 30 min. the display will show “E2” and
the unit stops. (if the HGV does not open this
could also give you an “E2” error)
The harvest cycle is controlled by thermistor
when the defrost completion temperature of
18.5ºC or more is reached the HGV closes, the
fan motor starts, and the water pan starts
closing.
As before there is a timer that starts as soon as
the water pan starts to close. If the hall IC
(magnetic Switch) does not turn on within 3
min. the machine will stop and give a “EE”
error and the machine shuts down for 60
minutes if the error reoccurs after restart the
unit will shut down again and again shows
“EE” (recorded as ‘E4” in the error history).
NOTE: in the initial cycle or when the water is
below 48ºF (9ºC), the water valve will open to
supply defrosting water for 10 second after the
water pan starts to close.
To check the resistance between thermistor
leads, follow the steps below.
1) Disconnect the connector CN13 on the
board.
2) Remove the screw and the thermistor holder
on the evaporator.
3) Immerse the sensor part in a glass containing
ice and water for 2 or 3 minutes.
4) Check the resistance between thermistor
leads. Normal reading is within 5 to 7 kΩ
Replace the thermistor if it is
outside the normal reading.
Hall IC Switch is located on the
motor backside. (Magnetic Switch)

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WATER PAN CLOSES/FREEZE:
When the water pan closes and the hall
IC turns on the water valve opens to
supply ice making water for a specific
time. The supply time varies between
startup, reset, and end of bin control
cycle between partial flush and full
drain.
NOTE Full drain flush: After a freeze
cycle ends the unit drains all remaining
water out of the tank and refills for the
next freeze cycle.
Partial drain flush: (default setting)
After a freeze cycle ends, the unit leaves
remaining water in tank and adds water
for the next cycle.
After water has been supplied the pump
motor starts, after 30 seconds the
thermistor senses the temperature that
will be added with a predetermined
offset value and used as the water
temperature for the freeze cycle, pan
opening, defrost, and pan closing cycle.
The freeze cycle is considered to be
100% complete when the predetermined
target and the integrated values are
reached. To reduce ice forming on the
water pan when the freeze completion
rate reaches 100% with an ambient
temperature below 86ºF (30ºC), the hot
gas valve opens and closes two times to
raise the water pan temperature and the
actuator motor starts to open the water
pan. The freeze cycle is not considered
complete and the pump motor and fan
motor continue. The unit will continue
to cycle between freeze and harvest until
the bin control opens, signaling a full
bin or until power is interrupted

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The IM-500SAA uses a mechanical bin
control located on the right rear side of
the ice drop zone. This control will open
when ice pushes against the switch, if the
switch stays open for more than 10
seconds the machine will start the bin
control cycle, starts and the machine will
shut down after the next defrost cycle.
After the bin control stays closed for
more than 80 seconds the bin control
cycle will end and the machine will
restart.(the hot gas valve opens 30
seconds before the icemaker restarts)
After the bin control cycle ends (or when
the power supply is turned on), the water
pan starts to open.
When the water pan opens and the hall
IC turns on, the bin control cycle starts
after 10 seconds and the ice maker stops.
.

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The control switch is marked “ICE-
OFF-WASH” and is located on the upper
right front of the unit.
“OFF” – No power supplied to unit
“ICE” – Starts the automatic Ice making
process
“WASH” – Power is supplied to water
pump (this allows for cleaning and/or
sanitizing
“RESET”- If the reset is pushed after the
unit is turned to ICE the soft start is
skipped after 3 seconds the water pan
starts to open in the initial cycle.
If pressed and released during operation
(water pan opening or closing, defrost or
freeze cycle), the machine will return to
the initial cycle within 3 seconds and the
water pan starts opening.
If pressed and released while the
machine is in the off or bin control cycle
the machine will return to initial cycle
within 3 seconds the bin control cycle
ends and the water pan starts to open.
If pressed and released while machine is
in the off on an error the machine will
return to the initial cycle within 3
seconds, the error is reset and the water
pan starts to open.
NOTE: When the machine returns to the
initial cycle by the reset switch the water
temperature is assumed to be 32ºF (0ºC)
[below 48º F (9ºC), the freeze backup
timer is extended.

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CONTROL BOARD:
A solid state board controls the IM
operation. The control board is factory
adjusted to produce consistent ice in all
ambient conditions.
“NO SEASONAL
ADJUSTMENTS ARE
REQUIRED”
If it becomes necessary to install a new
IM-500SAA control board, part number
P01873-01, the model code must be
programmed into the board before the unit will
operate properly
Follow the steps below for programing:
1. Once the board has been installed, apply
power to the unit and turn the switch on.
2. “00” will appear on the display of the
new board
3. For the IM-500SAA, set the model code
to “08”
4. Press service button “1” to increase the
first digit and service button “2” to
increase the second. Note: It should
only be necessary to adjust service
button “2” in order to get the IM-
500SAA model code of “08” displayed.
5. Digits will appear in the following
order: 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F.
6. When a valid model code is displayed,
the dot in the bottom right of the display
turns on.
7. When the desired model code “08” is
displayed, press the reset button to save
the setting. “ON” will appear in the
display.

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Preventative maintenance:
Follow these steps to allow the unit to
operate efficiently.
1. Clean the condenser once a year
using a brush or vacuum.
2. Check and clean the inlet water valve
screen as needed to assure proper
water flow.
3. Clean and sanitize the water
distribution system annually using the
recommended cleaner. (See below for
detailed information on cleaning the
water system)
4. Wipe down the exterior using a soft
cloth and neutral cleaner.
Cleaning tips:
A detailed cleaning label is located on
the back of the ice maker front panel.
More detailed instructions are
included in the customers Instruction
Manual or in the product Service
Manual.
Always follow the cleaning
instructions and use the
recommended ice machine cleaner.
Cleaning Label inside front
panel.

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1) Dilute approximately 7.2 fl. oz. (214
ml) of recommended cleaner Hoshizaki
“Scale Away” with 0.8 gal. (3.0 lit.) of
water.
2) Turn off the power supply.
3) Remove all ice from the storage bin.
4) Remove the front panel.
5) Remove the screw, and then move the
water tank drain pipe to the drain
position. See Fig. 5. Use the screw to
secure the water tank drain pipe in the
drain position.
6) Make sure the control switch is in the
“ICE” position, and then replace the
front panel.
7) Close the icemaker water supply line
shutoff valve.
8) Turn on the power supply for 3
minutes. The water tank drains and cubes
are removed from the evaporator.
9) Turn off the power supply.
10) Remove the front panel and top
panel.
11) Move the control switch to the
“WASH“ position.
12) Slowly pour the cleaning solution
over the top of the evaporator and into
the water tank. Do not splash or spill the
solution onto other parts.
13) Replace the front panel and top panel
in their correct positions.

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14) Turn on the power supply to start the
washing process.
15) Turn off the power supply after 30
minutes.
16) Open the icemaker water supply line
shut-off valve. See Fig. 4.
17) Remove the front panel.
18) Move the control switch to the "ICE"
position.
19) Replace the front panel.
20) Turn on the power supply for 3
minutes. The water tank drains.
21) Turn off the power supply.
22) Repeat steps 20 and 21 three more
times to rinse thoroughly.
SANITIZING:
1) Dilute a 5.25% sodium hypochlorite
solution (chlorine bleach) with water
(add approximately 0.4 fl . oz. (12
ml) to 0.8 gal. (3.0 lit.) of water).
2) Close the icemaker water supply line
shut-off valve.
3) Turn on the power supply for 3
minutes. The water tank drains.
4) Turn off the power supply.

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5) Remove the front panel and top
panel.
6) Move the control switch to the
“WASH“ position.
7) Slowly pour the sanitizing solution
over the top of the evaporator and
into the water tank. Do not splash or
spill the solution onto other parts.
8) Replace the front panel and top panel
in their correct positions.
9) Turn on the power supply to start the
sanitizing process.
10) Turn off the power supply after 15
minutes.
11) Open the icemaker water supply line
shut-off valve.
12) Remove the front panel.
13) Move the control switch to the
“ICE“ position.
14) Replace the front panel.
15) Turn on the power supply for 3
minutes. The water tank drains.
16) Turn off the power supply.
17) Repeat steps 15 and 16 three more
times to rinse thoroughly.
18) Repeat steps 1 through 17 one more
time.
19) Remove the front panel.
20) Remove the screw, then move the
water tank drain pipe to the
normal position. See Fig. 5. Use
the screw to secure the water tank
drain pipe in the normal position.

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21) Replace the front panel.
22) Clean the storage bin liner using a
neutral cleaner. Rinse thoroughly
after cleaning.
23) Turn on the power supply to start the
automatic ice making process.

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Electrical Specifications:
The unit is 115 volt/ 60 hz./1ph.
The IM-500SAA should be connected to a separate 20 Amp circuit.

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