Automatic Ice Maker
Service Manual
MIM-50, MIM50-O
1
Table of contents
How the Icemaker works ------------------------------------------------------------3-10
Cooling System -----------------------------------------------------------------3
Water System ----------------------------------------------------------------- 4-5
Wiring Connections and Controller------------------------------ ----------6-8
Exploding Drawing -----------------------------------------------------------9-10
TroubleShooting ------------------------------------------ --------------------------- 11-17
Before Maintenance-------------------------------------------------------------11
Basic Checking ------------------------------------------------------------------11
TroubleshootingGuide------------------------------------------------------ 12-17
Adjustment and Replacement----------------------------------------------------- 18-19
Replace the controller----------------------------------------------------------18
Replace the water pump-------------------------------------------------------18
Replace the compressor-------------------------------------------------------19
Replace the fan motor and fan blade------------------------------------ ----19
Replace the hot gas valve, drier and evaporator-------------- -------------19
IMPORTANT: The service manual is based on the user manual. Before servicing, please read
user manual and service manual carefully. The service operation should be implemented by
qualified technician.
2
How the Icemaker Works
Please refer to the section “Operation of user manual” from page 13 to 16 . It describes clear how
the icemaker makes ice and uses the water.
There are 3 systems including Cooling System, Water System and Wiring Connection and
Controller.
Cooling System
NUMBER DESCRIPTION
1 Condenser
2 Multi-connection pipe
3 Hot gas solenoid valve
4 Drier & Filte
5 Capillary tube
6 Hot gas tube
7 Suction tube
8 Compressor
9 Fan motor
9.1 Fan motor support
3
9.2 Fan blade
10 Discharge tube
19 Wiring harness
39.1 Temperature sensor of the condenser
39.2 Temperature sensor of the evaporator
46 Evaporator (Ice Mold)
39 Controllerbox
During the ice-making stage, the hot gas solenoid valve is closed. The hot refrigerant gas is
pumped out off compressor to condenser. The hot gas is cooled by fan forced air to warm liquid
refrigerant after passing through the condenser. The drier & filter reduces the possible dirty and
humidity in the refrigerant. The evaporator is cooled by the refrigerant. So ice can formed on the
evaporator during water is sprayed to the evaporator. Low pressure refrigerant gas may go back
compressor from the evaporator.
During the ice harvest stage, the solenoid valve is open. The hot refrigerant gas is pumped out off
compressor to evaporator through hot gas valve. As the hot gas is not cooled by the condenser, the
refrigerant makes the evaporator (ice mold) warm. So some ice touching the evaporator is thawed.
All of ice can slide down to the ice storage bin.
Water System
When the water supply pipe is connected with the main water supply, water will fill the water
trough through the floater valve till enough water inside water trough makes floater valve close.
During ice-making stage, water is pumped from the water trough to the water distribution tube. The
distributed water flow the surface of evaporator. Most parts of water go back water trough. Some
water is frozen on the evaporator step by step. The floater valve will open and fresh water is
recruited at any moment.
4
NUMBER DESCRIPTION NUMBER DESCRIPTION
23 Water pump 25 Water pump inlet tube
26 Water pump outlet tube 32 Floater valve
33 Water inlet 34 Nut of water inlet tube
36 Water inlet tube 38 Water supply pipe
45 Water distribution tube 46 Evaporator
48 Ice slideway 49 Ice full probe
57 Water trough 59 Water trough drain tub
5
Wiring Connection :
Circuit Description
1. Electrify Status For The First Time
As the icemaker is properly installed. switch on the water tap, let the water trough full (reach on the
level), then turn the ICE/OFF/WASH switch to the ICE position on the front panel. The icemaker
will start working automatically
In this status, the time is fixed about 3 minutes. This function is also helpful to protect the
compressor avoiding restart within 3 minutes.
At this status, the Red, Green, Yellow LEDs are light together.
2. Ice-making Status
The compressor, motor fan and pump are powered on. The hot gas solenoid valve is powered off.
When this green LED is lit, the unit is working in the ice making mode controlled by a temperature
probe on the evaporator. When the green LED is flashing, the unit is working in the ice making
mode controlled by a fixed timer.
The fan motor is also controlled by a condenser sensor. When the ambient temperature is too lower,
the motor fan stop working for good condensation to refrigerant.
3. Ice Harvest Status
The pump is powered off. The hot gas solenoid valve, compressor and motor fan is powered on.
The fan motor is also controlled by a condenser sensor. When the ambient temperature is too lower,
the motor fan stop working for good condensation to refrigerant.
The Yellow LED indicates the ice harvest status.
4. Ice Full Status And Cold Preservation Stage
If the ice bin is fulfilled with ice or the full sensor is covered, the machine stops making ice and turn
to cold preservation stage automatically.
In this status, the compressor works regularly to keep the lower temperature for lower ice melting.
The rest of the electric components are powered off. The RED LED indicates the ice full
status and the GREEN AND YELLOW LED together indicates the cold preservation status .
Controller box:
Instructions for LEDs and buttons:
1. Red LED: Ice full indicator light.
When this LED is lit, the ice storage bin is full of ice or there is something between the ice-full
sensor in the ice storage bin. The unit will stop making ice. When ice cubes are taken out of the ice
storage bin making the ice-full probe free, the red LED will keep flashing for 3 minutes. Then the
unit will restart and return to the ice making mode.
2. Green LED: Ice making indicator light.
When this LED is lit, the unit is working in the ice making mode controlled by a temperature probe
on the evaporator. When the green LED is flashing, the unit is working in the ice making mode
controlled by a fixed timer.
3. Yellow LED: Ice harvest indicator light.
When this LED is lit, the unit is working in the ice harvest mode controlled by ice-full probe .
When green LED and yellow LED is lit, it means the unit is working in the cold preservation stage .
4. Mode button:
Mainly for service. When this button is pressed, it can change from ice making mode to ice harvest
mode, or from ice harvest mode to ice making mode. You can judge the mode from the status of the
green and yellow LEDs.
Ice Size Adjustment Guide:
1. Press and hold the “Clean” button and the “Mode” button together for at least 3 seconds. The
unit will enter the Ice Size Adjustment mode. The “HARVEST” LED (yellow) will be blinking
continuously during the ice size adjustment.
2. While in the Ice Size Adjustment mode, press the “Clean” button or the “Mode” button for the
desired ice size.
Smaller ice setting:
By pressing the “Clean” button, you can decrease the size of the ice cubes. The “ICE” LED
(green) will flash as you lower the ice size and will finally be blinking at the setting of smallest
ice size.
Larger ice setting:
By pressing the “Mode” button, you can increase the size of the ice cubes. The “BIN FULL”
LED (red) will flash as the larger size is set and will blink when the setting of largest ice size
has been reached.
After 10 seconds without any operation, the unit will return to the previous mode.
NOTE: During the ice size adjustment, the “BIN FULL”, “ICE” and “HARVEST” LEDS
blinking all at once indicate that the unit is in the default factory setting of the ice size.
MAJOR FUNCTIONS
1. The operating procedure is completely automatic.
2. When the ice storage bin is full of ice cubes，the machine stops making ice and proceeds to the
cold preservation stage automatically. It starts making ice again after ice cubes are removed.
3. The different colors of the LED display indicate various work modes.
4. The fan motor responds to the ambient temperature. If it is cold, the motor will stop working to
keep the cooling system in good working condition.
5. A sensitive probe and accurate timer enhance the performance of the ice maker.
6. A compressor protection system is built in.
Exploding Drawing
Item No.
Part Number
Description
1
1885000202
Condenser
3
1854703321
Hot gas valve coil（Zhongbao）
3.1
1854703310
Hot gas valve body (Zhongbao)
4
1880007500
Drier
8
1858421900
Compressor
8.1
1858460900
Starting ralay
8.2
1858451100
Protector
9
1858200601
Fan motor
9.2
549738100
Fan blade (φ200X28°)
14
1880014701
Left foot
15
1880014801
Right foot
19
1853703503
Wiring harness
20
1853113800
Power cord
23
1858900600
Water pump
30
1845744001
Louver
32
1880001701
Floater valve
33
1864526301
Water inlet
34
1864529100
Nut of the water inlet tube
38
1811306020
Water supply pipe
39
1854205801
Control box
39.1
1851700401
Temperature sensor of condenser
39.2
1851700501
Temperature sensor of evaporator
39.3
1854800500
Fuse
43
1864400101
Top hinge cover
44
1864800100
Ice scoop
45
1880001601
Water distribution tube
46
1880017702
Evaporator(Ice Mold)
48
1861701601
Ice slideway
49
1854005700
Ice full senser
55
1864805201
Ice storage bin
63
1811306015
Drain pipe
10
Troubleshooting
ELECTRICAL SHOCK HAZARD
Disconnect Electrical Power Before
Beginning Removal of Parts
Before Maintenance
1. Check out the user if the user uses a 115 VAC, 60Hz. only 15ampere electrical supply, and have
properly grounded, ensure the maintainer against electrical shock.
2. Check out the leads loose? Turn off? Short circuit? If have such problems, foreclose in turn.
Basic Checking
The icemaker has some trouble, through the appearance phenomena judges. So the service
technician must check it thoroughly, then maintain.
Hearing
Hearing the user 's depiction about the icemaker at using process and the phenomena. Try to
understand what is the defect and how did the user operate the icemaker before calling for
service.
If the running sound is normal?
Looking
Check the pipe of cooling system, especially the welding point. If there is some oil, the gas is
leak out so that no ice making or less ice produced.
If the cycle of the ice making and harvest is normal?
Check the water system, especially the connection. If there is some water leakage.
Check if the water filter needs to be replaced.
Check if the icemaker installed according to the user manual.
Check if the icemaker needs to be cleaned.
Touching
Touch the hot gas pipe (with the evaporation weld), feeling the temperature. At the ice making
stage, feeling cool. At the ice harvest stage, feeling hot.
Touch the capillary tube (the drier nearby), feeling tepefaction.
Troubleshooting Guide
This troubleshooting guide in the user manual should be read before this guide. Be sure only when
the trouble shooting in user manual can’t help you solve the problem, turn to this guide.
Troubleshooting Guide
.The machine does not make ice
11
Proble
m
kinds
Check
part or
point
Possible Cause
Probable Correction
The
machin
e don't
operate
Plug
The icemaker is
unplugged.
Plug the icemaker in.
Socket
Socket is damaged
Check and replace
Power
switch
The icemaker power
switch turns to OFF.
Turn the icemaker power switch
to ICE.
Fuse
The fuse is blown.
Replace fuse.
Wiring
connection
Some wiring connection
is incorrect or loosed
Check and re-connect
Voltage
The voltage of the power
supply is low.
Add manostat.
Ice full
probe
The ice full probe is out
of function.
Replace a new one.
Ice full
probe
The ice full probe is
covered by something
Clear the probe and make the
ice-full probe is free.
wiring
Some wiring is damaged
Replace a new one
Electric
component
Some electric component
fail
Find the controller, press the
mode button to change the mode.
It is helpful to judge which part is
out of function
Controller
The controller fail
Replace a new one
Water
System
Water
supply tap
The water supply tap is
turn off.
Turn on the water supply tap.
Water
supply
pipe
The water supply pipe
is not proper connected or
maybe kinked
Reconnect the water supply pipe.
Water line
Some water line leaks.
Plug into again.
The water line blocks
Clean it, see user and care
manual "ice making system
cleaning"
Water supply pressure is
lower.
Adjust the water supply pressure
within the range of stated range.
Water inlet
Water inlet blocks
Check and clear it
Water
pump
Water pump damages
Replace water pump.
The room temperature is
out the stated range, the
water pump stop
automatically.
Make the temperature returns
within the stated range.
The lines of the water
pump loose.
Plug into again
The housing of water
pump leaks.
Replace water pump.
12
Drainage
tray on top
of the
compressor
Drainage tray on top of
the compressor is full
Drain off water by unscrewing
lower drainage nut.
Problem
kinds
Check
part or
point
Possible Cause
Probable Correction
The
compresso
r doesn't
start or
start
frequency
Wiring
connects
loose.
Plug tightly, or replace.
The start
relay/ther
mal
protect
Be damaged.
Replace the start relay/thermal
protect of the compressor
The
startup
coil /
running
coil
Be turnoff.
Replace the compressor.
The motor of the
compressor is short
circuit.
Replace the compressor.
Condenser
The condenser may be
dirty.
Clean the condenser.
Fan
The fan may be dirty or
damaged
Clean or Replace the fan .
The
Electronic
controller
The controller is damaged
Replace the Electronic
controller.
The
compresso
r run
but no ice
Refrigeran
t
Refrigerant leaks
completely
Add low side access valve,
locate leak, recover refrigerant,
replace drier, evacuate and
weigh in the data plate charge.
Capillary
tube
Capillary tube is blocked
Add low side access valve,
recover refrigerant, replace hot
gas valve, replace drier,
evacuate and weigh in the
nameplate charge.
Vent
The vent is obstructed
around the ice machine
Clean the vent
Hot gas
valve
Hot gas valve damaged
Replace
The
Electronic
controller
The model of making ice
doesn't turn to harvest.
Replace the Electronic
controller.
Tthe unit is working in
the cold preservation
stage mode controlled.
Work in normal mode
13
2.Low production
Problem
kinds
Check part
or point
Possible Cause
Probable Correction
Cooling
System
Refrigerant
Refrigerant leaks
partially
Recharge.
Condenser
The condenser may be
dirty.
Clean the condenser.
The ambient
temperature
The ambient
temperature is high or
too low
Check the ambient and air flow
Fan
The fan is dirty or
damaged
Clean or repalce
Hot gas valve
Hot gas valve
performance poor,
leads to few ice is
produced.
Replace the hot gas valve
Electronic
controller
The setting
temperature of
Electronic controller
is low.
See the service manual "adjust
the size of ice cubes"
Sensor
The sensor of
temperature damages
Replace the sensor of
temperature.
Water
System
Water
distribution
tube
The water distribution
tube blocks
Clean the water distribution
tube
Water line
The water quality is
too poor. The water
line blocks
Using a filter apparatus
installed in front of the water
inlet valve.
Silica gel
tubes
The silica gel tubes
distort, lead to block.
Make the silica gel tubes resile
Floater valve
The floater valve
leaks. Lead to few ice
produced.
Repair or replace
Wheel
The icemaker is not
proper leveled.
See installation
Problem
kinds
Check part
or point
Possible Cause
Probable Correction
Condenser
The condenser is dirty
or the air grills are
covered
Clean the condenser. Leave
space around the machine
3.Ice Cube is not OK
14
Cubes are
too small
The ambient
temperature
The ambient
temperature is too
high.
Adjust the ambient
temperature.
Electronic
controller
The setting
temperature is high.
See the service manual "adjust
the size of ice cubes"
Refrigerant
Refrigerant leaks
Recharge.
Cubes are
too big
Electronic
controller
The setting
temperature of
Electronic controller
is low.
See the service manual "adjust
the size of ice cubes"
Sensor
Temperature sensor of
the evaporator
damages
Replace the sensor of
temperature.
The ambient
and water
temperature
The ambient
temperature and water
temperature is too low.
Adjust the temperature.
The cubes
are
partially
formed--h
ave ragged
sides
Water quality
The water quality is
poor
Using a water-soften / filter
apparatus installed in front of
the water inlet valve.
Evaporator
Ice machine is dirty
Clean and sanitize the ice
machine
Water
distribution
tube
The water distribution
tube blocks partially
Clean the water distribution
tube
The room
temperature
The room temperature
is out the stated range,
the water pump stop
Make the temperature returns
within the stated range.
The ice
cubes
shape
deformity
Filter
Water filtration
element needs to be
changed
Replace the filter
Water trough
Water trough level is
too low
Adjust the water floater
Cubes are
partially
formed—a
re white at
the bottom
The room
temperature
The room temperature
is out the stated range,
the water pump stop
automatically.
Make the temperature returns
within the stated range.
Water trough
Water trough level is
too low
Adjust the water floater
4.Other problems
15
Problem
kinds
Check part
or point
Possible Cause
Probable Correction
The body
is
electrified
Earth line
The earth line isn't in
the socket.
Please use the socket meeting
the standard.
Lines
The lines are
creepage.
Adjust, reconnect /replace lines
Electric
component
The electric
component is
creepage,
Replace this electric
component.
Scales
occur
frequently
inside the
machine
the water
quality
The rigidity of the
water quality is too
high.
Using a water-soften apparatus
installed in front of the water
inlet.
Noise
during
operation
is big
Spring of the
internal
compressor
The spring of the
internal compressor
drops.
Replace the compressor.
Water pump
The noise of the water
pump
Replace the water pump.
Pipeline
system
Pipeline system
resonate
Clear pipeline system
Feet
The feet are not
leveled
Level and lock the feet.
Fan motor
The fan motor loose,
the clearance of the
rotor is bigger, the fan
blade turns back
Relocate the fan motor /
replace
Problem
kinds
Check part
or point
Possible Cause
Probable Correction
Water is
leaking out
the unit
The operation
A few water drops to
the floor when you
open the door to take
out ice from ice
storage bin.
Normal condensation on the
door or some water together
with ice. Take care when you
take out ice.
Water supply
connection
Water supply
connection leaking.
Tighten fitting.
Drainage tray
on top of the
compressor
Water full probe is out
of function
Replace the new one.
Water line
Some water line leaks.
Plug into again.
The water
distributio
Lines of the
water pump
The lines of the water
pump loose.
Plug into again
Water pump
Water pump damages
Replace water pump.
Water
distribution
tube
The water distribution
tube blocks
Clean the water distribution
tube
16
n tube
doesn't
spray
Ice full probe
The ice full probe is
broken or can not turn
back normal position.
Repair or replace the probe
The room
temperature
The room temperature
is out the stated range,
the water pump stop
Make the temperature returns
within the stated range.
Harvesting
ice is
difficult
Hot gas valve
The hot gas valve is
poor,
Replace the hot gas valve
The hot gas valve
damage
Replace the hot gas valve
Ice mold of
the
evaporator
The ice mold is
dirty, or polishing
degree is poor.
Clean the ice mold, or replace
the evaporator.
Refrigerant
Refrigerant leaks
Recharge
Ice machine
Ice machine is not
proper leveled
Level the ice machine
The ambient
and water
temperature
The ambient and
water temperature is
too low
Adjust the temperature.
Ice cubes size
The size is too big.
See “the adjust of ice cube
size”.
The
evaporator
is hot more
than 4
minutes
Hot gas valve
The lines of the hot
gas valve loose.
Plug into again
Hot gas valve
performance poor or
break
Replace the coil of hot gas
valve if only because of the
coil.
Refrigerant
Refrigerant leaks
Recharge
Electric
controller
The electric controller
is wrong
Check the controller
The
icemaker
make an
alarm
sound
regularly
The drainage
tray on top of
the
compressor
The drainage tray on
top of the compressor
is full.
Drain off water by unscrewing
lower the drainage nut.
17
Adjustment and Replacement
Expert advises the cube size have been adjusted
ok before leave factory, had better not adjust it.
Before replace the water system components, it will be
necessary to drain the system of water.
ELECTRICAL SHOCK HAZARD
Disconnect Electrical Power Before
Beginning Removal of Parts
Replace Controller, fuse and the sensor of temperature
Remove the rear cover, front panel,
Locate the Electronic controller,
Pull out the sensors of temperature (one at the evaporator, another at the condenser).
loosen the screws of rooting the Electronic controller, replace a new one. Reverse the above
step to replace.
If you need replace the fuse, open the front panel of the control box, you will find the figure.
According the figure, take out the fuse, replace a
new one.
Reverse the above step to reassemble.
If you need replace the sensors of temperature, pull out the sensor of temperature, open the
panel of the controller box, pull out the other side, replace a new one. Reverse the above step to
reassemble.
Replace the water system components
Please see the water system drawing. The water leakage should be checked after this kind of
operation
1. Replace the water pump
Disconnect electrical power.
Remove the rear cover.
Unplug the lines connector with the water pump, the water outlet tube of pump and the water
18
inlet tube of pump.
Loosen the screws, replace a new one.
Reverse the above step to reassemble.
Replace the cooling system components
Replace the condensing components, See Figure “cooling system”
1.Replace the compressor and the compressor kit (includes relay, thermal protect).
If only need replace the compressor kit, remove the rear, locate the compressor, take the clip,
open the cover, replace the wrong,
Reverse the above step to reassemble.
If need replace the compressor, remove the rear cover, and cabinet, locate the compressor.
Unplug the lines and taken out the earth line, add low side access valve, open the
Process/Suction, evacuate refrigerant, take out the compressor, replace a new one, joint together,
then recover refrigerant, weigh in the nameplate charge.
Reverse the above step to reassemble.
2. Replace the fan motor and fan blade.
Remove the front panel, rear and cabinet.
locate the fan motor, unplug the lines connecting with the fan motor, loosen the screws of
holding fan motor bracket.
Replace a new one, If only need replace the fan blade, loosen the screws holding the fan blade,
taken out the damaged, replace a new one.
Reverse the above step to reassemble.
3. Replace the hot gas valve, drier and evaporator.
Remove the rear cover.
Locate the drier and hot gas valve, add low side access valve, recover refrigerant, replace the
drier and hot gas valve, evacuate and weigh in the nameplate charge.
Reverse the above step to reassemble.
If need replace the evaporator.
Remove the rear, locate the evaporator, add low side access valve, open the process/suction ,
weld open the two welds, replace a new one. Recover refrigerant, evacuate and weigh in the
nameplate charge.
Reverse the above step to reassemble.
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