MDT3F and MDT4F Manual
MDT3F & MDT4F
Purpose of this manual: To provide detailed
installation and operation instructions; to give
insights into how the machine works; to list
possible causes for problems; and to suggest
procedures for specific types of service.
New Table of Contents
Specifications: ··········································· Page 2
To The Installer: ·········································· Page 3
For The Electrician ········································ Page 4
For The Plumber·········································· Page 5
Wall Mount Kit (KWB4): ······································ Page 6
Final Check List & Initial Start Up ································· Page 7
User Operation ·········································· Page 8
Component Location & Function ································· Page 9
Refrigeration System Operation ·································· Page 10
The MDT3F and MDT4F are combination ice
makers and dispensers. The refrigeration system is
air cooled, using R-134a as a refrigerant. The
control system uses electric eyes as a bin control
and a water level sensor as the water safety
control. As ice is made, it fills a plastic storage bin.
When ice is needed, a motor rotates a stainless
steel vane inside the storage bin and sweeps the
ice into the spout.
Water System Operation: ····································· Page 11
Mechanical Operation ······································· Page 12
Electrical Sequence ········································ Page 13
Maintenance: ··········································· Page 14
Dispense Area Sanitation ····································· Page 15
Auger and Bearing Inspection ··································· Page 16
Inspection: Auger ········································· Page 17
Inspection: ············································· Page 18
Service Diagnosis ········································· Page 19
Service Diagnosis ········································· Page 20
SERVICE DIAGNOSIS: Circuit Board ······························· Page 21
Removal and Replacement ···································· Page 22
Water System ··········································· Page 23
Bearings, Water Seal and Auger ································· Page 24
Bearing Replacement: ······································· Page 25
Refrigeration System ······································· Page 26
Gear Reducer Removal ······································ Page 27
Auger Drive Motor ········································· Page 28
Parts Lists and Wiring Diagrams are printed on
yellow paper in the center of this manual.
This manual was printed on recycled paper. Keep it
for future reference.
May 2001
Page 1
MDT3F & MDT4F
6.00
23.63
Specifications:
Scotsman ice machines, like the MDT3F or
MDT4F, are designed to be installed indoors, in a
controlled environment. The minimum and
maximum operating conditions are:
Minimum Air Temperature: 50oF.
·
Maximum Air Temperature: 100oF.
·
Minimum Water Temperature: 40oF.
·
Maximum Water Temperature: 100oF.
·
60 Hz voltage may vary between 104 and 126
·
volts.
Water Pressure may vary between 20 and 80
·
psi.
Operating the machine outside these conditions
constitutes misuse and voids the warranty.
FRONT
34.25 IN
87.00 CM
SIDE
EXHAUST
6.00 IN
15.24 CM
MINIMUM
CLEARENCE
BOTTOM
SIDE
AIR
INTAKE
6.00 IN
15.24 CM
MINIMUM
CLEARENCE
15.52 IN
39.41 CM
1.57 IN
3.99 CM
Scotsman Ice Systems are designed and
manufactured with the highest regard for safety
and performance. They meet or exceed the
standards of UL, NSF and CUL.
Scotsman assumes no liability or responsibility of
any kind for products manufactured by Scotsman
that have been altered in any way, including the
use of parts and/of other components not
specifically approved by Scotsman.
Scotsman reserves the right to make design
changes and/or improvements at any time.
Specifications and designs are subject to change
without notice.
IN
60.11 CM
RIGHT SIDE
19.72 IN
50.09 CM
23.89 IN
60.67 CM
IN
15.24 CM
MINIMUM
CLEARENCE
ELECTRICAL
12.73 IN
32.32 CM
7.03 IN
17.86 CM
2.21 IN
5.61 CM
FLARE
WATER
INLET
3.97 IN
10.08 CM
2.06 IN
5.22 CM
4.57 IN
11.60 CM
BACK
14.00 IN
35.56 CM
OPTIONAL WATER INLET,
DRAINS, & ELECTRICAL
1.00 IN
2.54 CM
4.63 IN
11.75 CM
1.57 IN
6.13 IN
15.56 CM
3.98 CM
1.63 IN
4.13 CM
4.13 IN
10.48 CM
Specifications:
Model Number Dimensions
W"xD"xH"
Basic
Electrical
Refrigerant
Charge
(R134a)
Min.
Circuit
Ampacity
MDT4FA-1A 14 x 23 x 34¼ 115/60/1 14 oz. 15.1 20
MDT4FA-6A 14 x 23 x 34¼ 230/50/1 14 oz. 7.5 15
MDT3FA-1A 14 x 23 x 34¼ 115/60/1 12 oz. 9.4 15
MDT3FA-6A 14 x 23 x 34¼ 230/50/1 12 oz. 5.3 15
May 2001
Page 2
Max Fuse
Size
To The Installer:
MDT3F & MDT4F
A professional installation of any product is critical
to the long term satisfaction of the user. The ice
maker-dispenser is designed to be installed either
on a counter, or, using a wall hanging kit, hung
from a wall.
Determine the location from the anticipated use
and any options planned for.
This machine is air cooled and blows air out the
lower left side of the cabinet. Do not install the
machine where the side to side air flow might be
blocked.
Cooling Air Flow
Cooling Air
Flow
Water Quality:
The quality of the water supplied to the machine
will directly affect the purity of the ice and the
reliability of the machine. While the condition of the
water supplied to a building is normally out of the
control of the user, water can be treated at the
point of use.
There are two major types of water impurities:
suspended solids (those that are carried along with
the water and may be filtered out) and dissolved
solids (those that are part of the water and have to
be treated). A water filter is always a good idea,
but does require regular maintenance to change
the cartridge. In some water conditions, water
treatment may be required. Generally this means a
polyphosphate feeder of some kind. Water
softeners are not recommended.
General Installation:
Place the machine in its final location. Remove the
top, right and left side panels:
1. Remove two screws at the back of the top panel.
2. Pull up on the back of the top panel and remove
it.
3. Remove screws from the sides (top and bottom)
of the side panels and from the splash panel.
Warm Air
Exhaust
The machine will require electrical power, water
and a drain. Follow all local codes. Rough in the
utilities before placing the machine into position
(see For The Electrician and For The Plumber).
4. Pull the side panels back and off the machine.
Plumbing connections may be made thru holes in
the back of the cabinet or thru the base.
·
Route the sink drain to the back of the cabinet.
Route the bin drain to the back panel.
·
Route the electrical power cord from the
junction box inside the cabinet. thru the back
panel .
·
Route the inlet water line thru the back panel or
base to the flare fitting inside the cabinet.
Install the stainless steel panel kit (if used) now.
Install the back panel of the stainless steel panel
kit now (if used).
After all plumbing and internal wiring has been
done, replace the side and back panels.
Level the unit front to back and left to right.
The machine does not require sealing to the
counter due to the gasket on the base.
May 2001
Page 3
MDT3F & MDT4F
For The Electrician
Electrical connections:
Check the nameplate for voltage and current
requirements. An electrical cord is not supplied.
Connect the MDT3F or MDT4F to a separate
electrical circuit. Wiring to the machine must
conform to all codes. A licensed electrician may be
required in some situations.
Remove the back panel to make the electrical
connection. The electrical connection is made on
the terminal strip in the junction box inside the
machine. Replace the back panel when the
electrical connections are complete.
FOLLOW ALL APPLICABLE LOCAL, STATE
AND NATIONAL CODES
This Unit MUST BE GROUNDED
Electrical
Power
Remove Back Panel To
Expose Junction Box
May 2001
Page 4
For The Plumber
Drains:
The dispenser requires a gravity drain. The pitch
on the drain tubes must be at least ¼ inch fall per
foot of horizontal run. On long horizontal runs, a
vent at the back of the cabinet will improve
draining, and is recommended.
There are two drains to connect: A sink drain, a
plastic tube; and the bin drain, a
Install rigid tubing between the machine and the
building drain. Route the drains separately to the
building drain.
5
” plastic tube.
8
MDT3F & MDT4F
7
”
8
Water supply:
Connect cold, potable water to the machine. A
hand valve near the location is recommended. A
water filter is also a good idea.
Follow all local codes.
Strainer or
Filter
FOLLOW ALL APPLICABLE LOCAL, STATE
AND NATIONAL CODES
Water Inlet Fitting
(Inside Cabinet)
Water Supply
Bin and Reservoir
Overflow Drains
Sink Drain
Building Drain
(Typical)
May 2001
Page 5
MDT3F & MDT4F
Wall Mount Kit (KWB4):
Contents:
1. Top Case Hanger Bracket: Attaches to the frame
of the dispenser.
2. Top Wall Bracket: Mounts to the wall and
engages the top case hanger bracket to support
the dispenser.
3. Bottom Wall Bracket: Mounts to the wall and
spaces the base of the dispenser away from the
wall.
4. Bottom Fittings Cover: Fastened to the bottom
wall bracket to hide the utility connections.
Top Wall Bracket:
1. Hold the bracket on the wall where it will be
mounted.
2. Mark on the wall the positions of the holes in the
bracket.
3. If needed, drill pilot holes for the fasteners.
4. Secure the bracket to the wall with fasteners of
sufficient strength to hold up the MDT4F.
Bottom Wall Bracket:
1. Lift up and hang the dispenser from the top wall
bracket.
2. Position the bottom wall bracket so that the
molding on the dispenser base bottoms in the
channel of the wall bracket.
3. Secure the bracket to the wall.
Bottom Fitting Cover:
1. Connect electrical power, water inlet, bin drain
and sink drain of the dispenser thru the bottom of
the case.
Top Panel
Installation: Check building wall for the strength
required to support a machine of this weight and
size. Note that if at least 6" of space is not left
above the machine, cleaning and most service of
the machine will require removal of the machine
from the wall mounts. All utilities are to be routed
thru the base. The back panel is not used when the
machine is hung from the wall.
Top Case Hanger Bracket
1. Remove top panel.
2. Remove back cover and save the 4 screws for
mounting the bracket.
3. Drill out the holes (as marked in the illustration)
in the back of the frame with a 3/16" drill bit.
4. Place top hanger bracket on the inside of the
frame and fasten to the frame with the four screws
removed in step 2.
Enlarge Holes
Top Case
Bracket
Bottom
Cover
Wall
Brackets
Secure With
Screws
2. Secure bottom fitting cover to the bottom wall
bracket with the four sheet metal screws provided
in this kit.
May 2001
Page 6
Final Check List & Initial Start Up
MDT3F & MDT4F
1. Is the machine located indoors where the
temperature limitations are not exceeded?
2. Is there at least 6" clearance on both sides of
the cabinet for adequate air flow?
3. Is the water supply adequate, and has a shut off
valve been installed?
4. Is the cabinet level?
5. Have all of the electrical and drain connections
been made?
Initial Start Up
1. Remove 2 screws at the back of the top panel
and remove the top panel.
2. Remove screws and the side panels.
3. Open the water supply shut off valve.
4. Watch the water fill the reservoir. Check that it
flows in and fills the reservoir near to the mark
molded into the side of the reservoir. Check that
the float shuts off the water flow when the tank is
full. Check for leaks. Tighten hose clamps as
needed.
5. Plug the unit in or switch on the electrical power.
After about 15 seconds the machine should start.
6. Let the machine operate, listen for any unusual
noises. If needed, reposition tubing & panels to
eliminate vibration.
After the unit has been operating for about 10
minutes, there should be enough ice in the bin to
test the dispense system.
7. Using a container, place in in front of the glass
sensor and below the ice chute. See that ice is
dispensed (the bin drive motor continues to run as
long as the container is in place).
8. Move the water switch (rocker switch on the
front panel) to ON. Place the container in front of
the glass sensor and under the ice chute. Both
water and ice should be dispensed.
9. Pour water into the sink and check that the drain
does not leak but drains the water rapidly.
10. Explain to the user the maintenance
requirements and operation of the machine.
11. Fill out the Warranty Registration and Customer
Evaluation form. Mail it to Scotsman.
12. Leave the service manual with the owner/user
and explain who should be called if service is
needed.
May 2001
Page 7
MDT3F & MDT4F
User Operation
The MDT3F and the MDT4F are automatic ice
vending machines. All either requires is cool air,
clean water and an adequate supply of electrical
power.
To Vend Ice:
Place a container in front of the Touch Free sensor
and below the ice spout. Hold it there until the
container is full of ice. Do NOT overfill the
container or a build up of ice in the sink or a back
up of ice in the spout will occur.
To Vend Ice and Water.
Switch the Water Switch to ON. Place a container
in front of the Touch Free sensor and below the ice
spout. Water and ice will be dispensed into the
container below the spout. Note: The water is NOT
cooled, it is the same temperature as the building
supply water.
Daily Maintenance: Pour hot water into the sink to
flush out any debris or build up. Wipe the cabinet
off, wash the sink and grill to keep minerals from
accumulating.
Caution:
Unless the touch free sensor is
de-activated by pushing the
Cleaning Switch in, ice and/or water
may be dispensed during cleaning.
The Cleaning Switch is a button,
located to the left of the ice chute,
that temporarily shuts off the sensor
for cleanup of the splash panel.
Pushing the button in will disable the
sensor for 2 minutes, pushing the
button in again will return the sensor
to normal operation.
Water
Switch
Glass
Sensor
Touch Free
Disable
Switch
May 2001
Page 8
Component Location & Function
Evaporator. This is a vertical cylinder full of water
and refrigerated. Also in the cylinder is a slowly
rotating auger. The auger forces the ice up the
evaporator walls and compresses it at the top. The
resulting flaked ice then falls by gravity into the ice
storage bin.
Water Reservoir. The water reservoir contains the
inlet float valve and the water level sensor. The
float valve controls the flow of water into the
reservoir, and the water level sensor will stop the
ice maker if the water supply fails.
Ice Storage Bin. The ice storage bin is an
insulated plastic container that is open at the top
and has a spout at the bottom. There is a rotating
ice vane inside the bin that causes the ice to be
swept over the spout and dispensed. The vane is
rotated by a gear motor at the top of the bin.
MDT3F & MDT4F
Bin Cover. The bin cover not only keeps dirt from
the ice storage bin, it also is the support for the
dispense gear reducer and the location of the
electric eye bin controls.
Condenser. The machine uses
an air cooled condenser. It blows
air out, away from the fan motor.
The heat removed from the water
is exhausted from the condenser.
Compressor. The refrigeration
system compressor provides the
force to move the refrigerant
around the system.
Auger Drive. The auger drive is
a direct drive gear reducer.
Compressor
Auger Drive
Water Reservoir
Evaporator
Bin Cover
Condenser
Ice Storage
Bin
May 2001
Page 9
MDT3F & MDT4F
Refrigeration System Operation
Both the MDT3F and the MDT4F use a forced draft
condenser, capillary tube and hermetic
compressor. The system uses R-134a as a
refrigerant. High pressure, high temperature
refrigerant is forced thru the condenser where it
looses enough heat to condense. The high
pressure liquid refrigerant then passes thru the
capillary tube which causes a pressure drop in the
evaporator. As the high pressure liquid refrigerant
moves into the evaporator’s area of low pressure,
the warm water and low pressure cause the
refrigerant to evaporate and absorb heat from the
metal walls of the evaporator. After the refrigerant
has flowed thru the evaporator it goes back to the
compressor thru the suction line as a low pressure
vapor. At the compressor the cycle is repeated.
Evaporator
System Characteristics:
Typical Low Side Pressure:
·
13 - 14 PSIG
Typical Discharge Side Pressure:
·
135 - 175 PSIG
System Refrigerant Charge:
·
14 ounces of R-134a
Compressor
Refrigeration System Schematic
Capillary Tube
Dryer
Air Cooled
Condenser
May 2001
Page 10
Water System Operation:
MDT3F & MDT4F
The water system consists of a float valve,
reservoir and water dispense solenoid valve. The
water level in the reservoir tank is the same level
as that inside the evaporator. Building water supply
flows to both the float valve and the solenoid. The
float valve will open to add water to the reservoir
as water flows out to the evaporator. The solenoid
will only open if the water switch is closed and the
touch free sensor initiates an ice dispense.
Electric Eyes
Ice
Dispensing
Vane
Water Seal
Evaporator
Inside the evaporator there is a water seal. This
seal is the type that has a rotating half and a
stationary half. The area where the two seals touch
are smooth flat surfaces. When the auger is
installed in the evaporator, it forces the rotating half
of the seal against the stationary half. The
stationary half is spring-loaded and provides a firm
pressure against the auger portion of the seal.
Water Level
Sensor
Float Valve
Inner Bin
Bottom
Water and Ice
Dispensing Spout
Water Dispensing
Solenoid Valve
Bin and
Reservoir
Overflow
Drain
Water Inlet
Connection
Sink
Water System Schematic
Sink Drain
May 2001
Page 11
MDT3F & MDT4F
Mechanical Operation
General:
The machine makes, stores and dispenses ice. It
also dispenses water. The ice making portion of
the machine produces flaked ice at about 32
The ice falls thru a chute into the dispensing bin.
Above the cylindrical bin is a dispense drive motor
and electric eyes. The drive motor is connected to
an ice vane in the bin. When the user holds a
container in front of the glass sensor and below the
ice chute, the dispense drive motor rotates the
vane and the ice. There is a slot in the base of the
bin, located just above the vend spout and glass
filler lever. When the ice moves over that slot,
some of the ice on the bottom of the bin falls thru
the slot, into the chute and fills the container.
ON/OFF Control:
Flaked ice is produced by the ice maker until ice
builds up between the electric eyes. When the
electric eyes can no longer “see” each other, they
send a signal to the control board to shut the
machine off. The refrigeration compressor stops
but the auger drive motor will continue to operate
for about 2 minutes to clear the evaporator of ice.
o
F.
Ice Vending
Dispensing takes place when the touch free
sensor’s infrared beam bounces back to the sensor
from a container placed directly in front of the
sensor and under the ice chute.
When the beam is reflected back, it signals the
circuit board to connect power to the dispense
drive motor, and ice is then moved over the slot in
the base of the bin, where it falls by gravity thru the
chute into the container.
If the Water switch is On, water is also dispensed
at the same time.
Dispensing continues until the beam is no longer
reflected back to the sensor.
Water Control:
Because water is such an important requirement
for making ice, a water level sensor has been
placed in the reservoir. If the water supply to the
machine should fail, the water level sensor will
send a signal to the control board to shut down the
machine.
Refrigeration:
The refrigeration system uses a hermetic
compressor (specifically designed for R-134a),
forced draft air cooled condenser, capillary tube
and vertical flaked ice evaporator. Inside the
evaporator is a slowly rotating auger. The auger is
supported by bearings at each end, and there is a
face-type water seal above the bottom bearing.
The auger is driven by a 1/10 HP direct drive gear
reducer. The auger drive motor has a speed
operated switch on it that will keep the compressor
from operating if the auger motor is not turning at
full speed.
Water System
Water flows from the building supply to the
reservoir and to the electric solenoid valve. Water
from the reservoir is used to make ice. Water the
flows thru the solenoid is dispensed.
Touch Free Sensor
The bin, sink and reservoir overflow all have
drains.
May 2001
Page 12
Electrical Sequence
MDT3F & MDT4F
Refer the wiring diagram as needed.
The “Power” light on the board glows whenever
there is power to the machine (and the master
switch is ON).
If the machine is switched off at the master switch,
but is otherwise ready to go, switching the master
switch to ON does the following:
The bin empty and power lights on the circuit
·
board glow.
There is a 15 second delay
·
If there is enough water in the reservoir, the
·
circuit board will allow the machine to start up.
Start up consists of:
The compressor contactor coil receives power
·
from the circuit board.
The contactor is energized, connecting power to
·
the compressor, and the compressor starts.
The auger motor receives power from the circuit
·
board and starts.
As ice goes past the ice level sensors, the bin
·
empty light will stay on and the machine will
continue to run, unless the ice stays between
the sensors for more than 15 seconds (bin full).
At that point, the bin empty light goes out, and
the machine shuts down.
Other reasons for shut down:
·
Low water level (as sensed by the thermistor in
the reservoir).
Shut Down consists of:
The compressor contactor opens
·
The compressor stops
·
The auger motor is run by the circuit board for 2
·
more minutes, clearing out ice in the evaporator,
and then
The auger motor no longer receives power from
·
the circuit board, and the auger motor stops.
After a 6 minute delay, If the ice level sensor is
clear (bin empty) for more than 15 seconds, the
machine will start up again.
Another purpose of the circuit board is to turn the
machine off if there is not enough water in the
machine.
When the water level in the reservoir falls below
·
the tip of the water level sensor, the machine
will “shut down”
After a 6 minute delay, if the water refills the
·
reservoir, the machine will start up again.
Ice Vending
When a user places a container in front of the
·
Touch Free ice sensor and below the ice
delivery chute, the circuit board connects power
to the bin drive motor and ice is dispensed for
as long as the container is present. If the user
does not remove the container, ice will be
dispensed for 60 seconds and then stop.
·
When a user selects water and ice dispensing,
water is also dispensed with the ice.
Splash panel cleaning:
A switch, located to the left of the spout, may be
pushed to disable the Touch-Free sensor for splash
panel cleaning. It automatically resets after 2
minutes, or, if pushed within the 2 minutes, resets
the circuit board to enable the Touch Free sensors.
May 2001
Page 13
MDT3F & MDT4F
Maintenance:
Although the ice in this dispenser is completely
untouched, the water and ice vending systems will
need to be periodically sanitized and
de-mineralized. The air cooled condenser will also
need to be kept clean.
Schedule the sanitation, cleaning and
de-mineralization on a regular basis to keep the ice
clean and the machine operating efficiently.
Sanitation and Cleaning
Water System:
This ice machine requires periodic sanitation and
de-mineralization.
1. Vend all ice from the machine.
12. Repeat steps 3-11, except substitute a locally
approved sanitizing solution for the cleaner. A
possible sanitizing solution may be obtained by
mixing 1 ounce of household bleach with 2 gallons
of clean, warm (95
o
F.-115oF.) water.
2. Remove top and right side panels.
3. Unplug or disconnect electrical power.
4. Shut off water supply.
5. Drain reservoir.
6. Mix 8 ounces of Scotsman Ice Machine Cleaner
and 3 quarts of hot (95
Scotsman Ice Machine
Cleaner contains acids.
These compounds may
cause burns.
If swallowed, DO NOT
induce vomiting. Give
large amounts of water or
milk. Call Physician
immediately. In case of
external contact, flush
with water.
KEEP OUT OF THE
REACH OF CHILDREN.
7. Pour the water into the reservoir.
8. Wait 15 minutes for the cleaner to dissolve the
minerals inside the evaporator.
9. Plug in the machine or reconnect electrical
power.
10. As the machine operates, pour in the balance
of the cleaning solution.
o
F. -115oF.) potable water.
13. Unplug or disconnect electrical power.
14. Remove bin top, pour in warm potable water to
melt out any ice.
15. Pull out the vane and bin bottom from the bin.
16. Thoroughly wash the bin’s interior, bin top
interior, spout, ice vane and bin bottom with the
sanitizing solution. Pour some down the bin drain.
17. Reassemble the bin bottom, vane and bin
cover.
18. Wash the sink area with the sanitizing solution
and pour sanitizing solution down the sink drain.
19. Replace all panels and reconnect water and
electrical power.
Air Cooled Condenser:
1. Disconnect electrical power.
2. Remove top panel
3. Remove right and left side panels.
4. Use pressurized air to blow the lint from the
outside of the condenser in towards the fan motor.
A vacuum cleaner hose placed on near the fan
motor should pick up most of the dust. Check for
interior dirt. If needed, use coil cleaner to
de-grease the condenser.
5. Replace all panels and reconnect electrical
power.
11. Reconnect water supply, operate the machine
for 15 more minutes, then switch it off.
May 2001
Page 14
Dispense Area Sanitation
1. The spout may be removed by taking out the
two mounting screws. Wash and sanitize it.
2. The sink grill may be removed for washing and
sanitizing.
3. The sink should be flushed with hot water and
wiped clean with sanitizer.
4. The splash panel requires special attention to
clean it.
Push and release the Cleaning Switch located
·
to the left of the ice spout. This disables the
Touch Free Sensor so the splash panel may be
cleaned without vending ice or water.
Wash the splash panel and wipe with sanitizer.
·
Re-push the clean switch or allow 2 minutes to
·
pass for the Touch Free system to reset.
MDT3F & MDT4F
May 2001
Page 15
Push Touch Free Sensor
Disable Button Before
Wiping Splash Panel
Pour Hot Water Into Sink
Regularly To Keep Drain
Line Open
MDT3F & MDT4F
Auger and Bearing Inspection
While in most areas regular in-place cleaning with
Scotsman Ice Machine Cleaner will be adequate to
keep the interior of the evaporator free of
excessive mineral build up, some water conditions
may require more intense methods. In addition, the
auger bearings require physical inspection to
determine that they are not wearing. This physical
inspection is recommended twice per year for the
top bearing and once per year for the auger and
both bearings.
Snap Ring
Cap
Cap Screw
Whenever the auger is removed, replacement of
the water seal is recommended.
If a bearing requires replacement, the other
bearing must also be replaced.
1. Unplug or disconnect electrical power.
Rotating Parts Hazard
Disconnect Electrical
Power Before Beginning
2. Shut off the water supply.
3. Remove top panel.
4. Remove right side panel.
5. Drain the evaporator and reservoir.
6. Remove foam cap on top of evaporator.
7. Remove 2 permagum plugs from the side of the
evaporator.
8. Remove 2 screws (screwheads were covered by
the permagum).
9. Pull up on the pull ring to remove the auger. If it
is difficult to pull:
Washer
Top Bearing
Set
Breaker
Screws
Breaker
Auger
Bottom
Bearing
A. Remove the breaker cover by taking the snap
ring out.
B. Unscrew the auger bolt.
C. Use threaded rod or a slide hammer puller and
screw into the auger, slide the weight quickly up
against the stop to remove the auger.
If the auger still will not move, bearing replacement
is mandatory. See Bearing Removal and
Replacement.
May 2001
Water Seal
Coupling
Adapter
Stand
Page 16
Inspection: Auger
MDT3F & MDT4F
The auger is made of stainless steel. It has a
polished surface that may be either shinny or dull,
but must be smooth. After removal, allow the auger
to dry to inspect for scale. If mineral scale is found
on the auger’s surface, clean off the auger with ice
machine cleaner and a scrubbing pad.
Remove the water seal and clean off the shoulder
of the auger.
Bearings: The top bearing should spin freely with
no rough spots. If it feels rough when spun by
hand, replace it. There should be minimal rust or
dirt. If in doubt, replace the bearing.
Note: The top bearing used in the MDT3F and
MDT4F is a “directional” bearing. Note which way
the inner race is configured and install into the
breaker. The breaker is also available as a
replacement part with the top bearing already
installed.
The bottom bearing must be removed from the
evaporator when replacing the water seal.
Remove bin cover.
Remote the three
bolts holding the
evaporator to the gear
motor adapter and lift
the evaporator up
slightly. Tap the water
seal and bottom
bearing out from the
top down. Check the
bottom bearing (the
same way as the top
one).
Replace the water
seal and install a new
bering set if needed.
Outer
Race
To replace the water seal:
1. Remove old rotating half from the auger. Clean
the mounting area.
2. Place a bead of food grade sealant (such as
Scotsman part number 19-0529-01) onto the
shoulder of the auger where the rotating half of the
water seal will be installed.
3. Wash the new seal in water. While wet, slip it
onto the bottom of the auger, rubber side toward
the auger. Push up until seated against the
sealant. Do not allow any sealant to come into
contact with the face of the seal.
4. Wash the stationary half the water seal with
water. Slip it up into the bottom of the evaporator
until the bottom of the seal is inside the evaporator
about 1/4".
5. Push the bottom bearing against the water seal
until the bottom bearing is inside the evaporator
about 1/16".
6. Replace the evaporator on the adapter, and
re-attach the stand using the original bolts.
7. Attach the auger to the top bearing
and breaker.
8. Return the auger to the evaporator
and slide it down until the splines touch
Inner Race
Wider on Top
Side
the coupling.
9. Rotate the auger until the coupling
splines align with the auger.
10. Push the auger down, and rotate
the breaker until the screw holes line up
with the pilot holes in the evaporator.
Open
Sides
11. When the auger is completely
seated, reinstall the breaker screws.
12. Replace permagum and foam top.
Sealant
Here
Rubber
Smooth
Side
13. Switch on the water supply.
14. Check bin cover for electrical
grounds and switch on the electrical
power.
15. Observe operation. The unit should
make minimal noise while producing
ice. Catch first 2 minutes of ice and
discard it.
16. Replace the bin cover and all
panels.
Water Seal
May 2001
Page 17
MDT3F & MDT4F
Inspection:
Photo-Electric Eyes
The photo electric eyes used to “see” the ice build
up in the top of the bin cover must be clean to get
a good “look” at the ice. If clouded by mineral
scale, the eyes will cause the ice machine to shut
off and stay off.
To clean the photo-electric eyes.
1. Remove the top panel.
2. Pull both of the photo-electric eyes out of their
rubber grommets.
3. Wash both eyes with a clean cloth dipped in
Scotsman Ice Machine Cleaner.
4. Wash the eyes off with clean water.
5. Replace the eyes in the grommets
6. Replace the top panel
Clean Photo-Electric
Eyes
Water Level Sensor
The water level sensor may not shut the ice
machine off when the reservoir goes dry if there is
a film of mineral scale on the probe tip.
1. Remove the top panel.
2. Remove the reservoir cover.
3. Pull the water level probe up and out of the
reservoir.
4. Carefully wipe the tip of the probe with a clean
cloth. Ice machine cleaner may be needed.
Note: The tip is made of glass.
5. Reinsert the water level sensor in the reservoir.
6. Replace the reservoir cover and the top panel.
Coupling
Use the grease zerk on the side of the coupling to
add grease once per year.
That concludes normal maintenance. If the fan
motor has an oil plug, it may be oiled after 10 years
of operation.
Clean Water Level
Sensor
Water
Reservoir
May 2001
Page 18
MDT3F & MDT4F
Service Diagnosis
PROBLEM POSSIBLE CAUSE PROBABLE CORRECTION
No ice is dispensed. No ice in bin due to:
No electrical power
·
Overuse
·
Water supply turned off
·
Bin controls dirty
·
Water sensor dirty
·
Control system malfunction
·
Auger drive motor open
·
Centrifugal switch open
·
Auger does not turn
·
No refrigeration
·
Ice in bin, but will not dispense:
Drive motor does not turn
Vend system does not work
·
·
Dispense motor open
·
Dispense output shaft broken
Ice in bin, motor turns vane.
Ice jammed up
·
Users held cup against
dispense spout and jammed
unit.
·
Bin bottom slot not over spout
·
Ice will not slide down bin wall,
bin out of round.
·
Wet ice in the bin from high
water level or high suction
pressure
Check/restore power
Recheck ice needs vs. machine
capacity.
Check water filter/hand valve/float
valve
Check & clean bin control (electric
eyes)
Check & clean water sensor
Check control system
Check auger drive motor
Check centrifugal switch
Check coupling & gear reducer
Check refrigeration system
Check/replace vend system
Check that cleaning switch has
been released.
Check/replace dispense motor
Check/replace output shaft
Advise owner/manager to instruct
users.
Check bin bottom position
Check bin interior wall for rough
texture or out of round.
Check water level, check suction
and discharge pressures
May 2001
Page 19
MDT3F & MDT4F
Service Diagnosis
PROBLEM POSSIBLE CAUSE PROBABLE CORRECTION
Unusual noise Mineral scale in evaporator Clean water system with ice
machine cleaner.
Auger coupling dry Grease coupling
Auger coupling worn Replace coupling and adapter
stand.
Bearings worn Replace bearings and water seal.
Gear motor loose on frame Tighten bolts, check grommets
Low water level Check water level in reservoir
Tubing vibrating Check tubing for contact
Tooth on a gear missing Check gears in auger drive
Compressor too loud Replace compressor
Gear noise Check gear motor for oil leak
No water is dispensed Water Switch in Off position Switch to ON
Water switch open Replace switch
Water solenoid plugged up Clean inlet screen of solenoid
Water solenoid coil open Replace solenoid
Vend system does not work Check/replace vend system
Water turned off Restore water supply
Water drips from spout Melting ice in chute Some water dripping is normal
Unit or bin not level Level unit, check bin
Water solenoid leaks thru Replace solenoid
Ice jammed in spout Clear ice jam, check for cause
Ice will not stop dispensing Vend system does not work Check/replace vend system
Water leaks from cabinet Evaporator water seal worn or
cracked
Tubing to evaporator leaks Replace tubing/fittings
Drain leaks Check drain tubes and fittings
External drain restricted Clean out drain
No refrigeration Gear motor does not turn Check motor
Centrifugal switch does not close Check switch
Fan motor does not turn Check fan motor
Lack of refrigerant Add refrigerant, if problem is
Compressor does not pump Check/replace start capacitor
Replace seal and bearings
reduced, locate leak and repair it.
Check/replace start relay
Check/replace compressor
May 2001
Page 20
SERVICE DIAGNOSIS: Circuit Board
MDT3F & MDT4F
1
2
3
Explanation of Indicator Light Position On
Board
On at all times when the master switch is ON and machine is
connected to electrical power.
On when ice level is low (unit making ice).
Normal 6 minute off/delay start. To prevent short cycling, the
machine will not restart after any shut off (except power to the
board) until 6 minutes have passed.
On when water level is low in the reservoir.
To check the electrical system, first check the lights on the circuit board.
1. Remove the top panel.
1
2
3
4
4
Name and Meaning of
Light or Reset
Power,
ON = Normal
Bin Empty,
ON = Needs Ice
Off Timer,
ON = Unit cycling off
No Water,
ON = Trouble
2. Remove the left side panel.
3. Remove the control box cover.
May 2001
Page 21
MDT3F & MDT4F
Removal and Replacement
Panels:
1. Remove two screws at the back of the top panel.
2. Lift up at the back and push the top panel
forward to release it.
3. Remove 3 screws at the top, 3 screws at the
bottom and 1 screw at the front edge of each side
panel.
4. Push each side panel to the rear to release the
panel from the cabinet frame.
Dispensing System
The dispensing system consists of the vend switch,
dispense motor, dispense vane, bin bottom and
bin.
Electrical Shock Hazard.
Disconnect electrical
power before beginning.
Dispense Vane
1. Disconnect electrical power.
Dispense Drive
Motor
Bin Top
Dispense Gear Motor
1. Disconnect electrical power.
2. Remove top panel.
3. Remove one screw holding ground strap to
cabinet frame.
4. Cut off two dispense motor wire nuts.
5. Remove screws holding dispense drive gear
motor to the bin top.
6. Pull gear motor off the bin top.
7. Unscrew the output shaft extension from the
gear motor.
8. Remove screws holding the mounting bracket to
the gear motor.
9. Reverse to reassemble, be certain that the new
wire nuts are secure and that the ground strap is
reattached.
2. Remove top panel.
3. Remove four thumb screws holding bin cover to
bin.
4. Lift bin cover off bin. Set aside.
5. Grasp the ice vane and pull it straight up.
6. Reverse to reassemble.
Bin Bottom.
Perform steps 1-5 above (to remove the dispense
vane).
1. Lift bin bottom out of the dispense bin.
2. When replacing, be sure that the slot on the bin
bottom is over the dispense chute (at the front).
May 2001
Page 22
Water System
MDT3F & MDT4F
The water system consists of the reservoir and
inlet water valve.
Reservoir.
1. Shut off the water supply.
2. Remove the top panel.
3. Remove the right side panel.
4. Drain the water reservoir and evaporator.
5. Disconnect inlet and outlet tubes from the
reservoir.
6. Remove screws holding reservoir to its mounting
bracket.
7. Remove reservoir from the machine.
8. Reverse to reassemble.
Float Valve
1. Shut off the water supply.
2. Remove the top panel.
3. Remove the reservoir cover.
Valve Plunger
1. After the valve has been removed from the
reservoir, remove the nut holding the valve to its
mounting bracket.
2. Pull out the cotter pin to release the internal
valve plunger.
Note: Do not replace the plunger if the valve’s seat
is damaged. Replace the valve.
Inlet Water Valve.
1. Disconnect electrical power.
2. Shut off the water supply.
3. Remove the top panel.
4. Remove the right side panel.
5. Remove wire harness from inlet water valve.
6. Remove tube connecting outlet of the valve to
the dispense tube.
7. Rotate the valve to unscrew it from its inlet
fitting.
4. Remove the water inlet tube.
5. Push in the mounting tabs at the back of the
reservoir and lift the valve out of the reservoir tank.
6. Replace with a new valve or replace the valve
plunger.
Plunger
8. Reverse to reassemble.
Valve
Water Level
Sensor Slot
May 2001
Page 23
MDT3F & MDT4F
Bearings, Water Seal and Auger
1. Disconnect electrical power.
Rotating Parts Hazard
Disconnect Electrical
Power Before Beginning
2. Shut off the water supply.
3. Remove the top panel.
4. Remove the side panels.
5. Drain the reservoir and evaporator.
6. Remove foam cap from the top of the
evaporator.
7. Remove the two permagum plugs from the side
of the evaporator.
8. Pull up on the ring to lift the auger out of the
evaporator.
If the auger will not lift out:
1. Remove snap ring holding bearing cover to
breaker.
2. Remove bearing cover.
1. Remove three cap screws holding evaporator to
the adapter stand.
2. Lift evaporator up slightly and tip the bottom out
to expose the splined end of the auger.
3. Remove snap ring holding bearing cover to
breaker.
4. Remove bearing cover.
5. Unscrew bolt holding bearing to auger.
6. Screw a length of threaded rod or a shoulder
screw into the auger.
7. Tap on the end of the threaded rod to push the
auger out of the bottom of the evaporator.
8. Replace the bearings and water seal. Replace
the auger if the splines are damaged. Replace the
evaporator if more than 1/3 of the vertical rifle
grooves are gone. Sand or hone and sand the
inside of the evaporator if mineral build up is
heavy.
Snap Ring
Cap
3. Unscrew bolt holding bearing to auger.
4. Thread in a threaded rod and weight or
slide-hammer puller into the auger.
5. Use the threaded rod & weight or slide hammer
puller to remove the auger.
Or
1. Remove three cap screws holding evaporator to
the adapter stand.
2. Lift evaporator up slightly and tip the bottom out
to expose the splined end of the auger.
3. Use a plastic mallet or dead-blow hammer to tap
the bottom of the auger and force the auger up. Do
NOT damage the splines of the auger or the auger
will have to be replaced.
If the auger is “frozen” to the bottom bearing, do
not force the bottom bearing thru the evaporator.
Bolt
Washer
Top Bearing
Breaker
Auger
Water Seal
May 2001
Page 24
Coupling
Bearing Replacement:
MDT3F & MDT4F
Top Bearing Replacement
If the inner race is secure, use an arbor press to
push the top bearing out of the breaker. If the inner
race has separated from the bearing, replace the
breaker.
Insert a new bearing in the breaker, check for
orientation:
The top of the bearing has a wider inner race and a
narrower outer race than the bottom.
Replace the “O” ring in the breaker.
Push the bearing in, push only on the outer race.
Water Seal & Bottom Bearing Replacement:
1. Remove old rotating half from the auger. Clean
the mounting area.
2. Place a bead of food grade sealant (such as
Scotsman part number 19-0529-01) onto the
shoulder of the auger where the rotating half of the
water seal will be installed.
3. Wash the new seal in water. While wet, slip it
onto the bottom of the auger, rubber side toward
the auger. Push up until seated against the
sealant. Do not allow any sealant to come into
contact with the face of the seal.
4. Wash the stationary half the water seal with
water. Slip it up into the bottom of the evaporator
until the bottom of the seal is inside the evaporator
about 1/4".
5. Push the bottom bearing against the
water seal until the bottom bearing is
inside the evaporator about 1/16".
6. Replace the evaporator on the adapter,
and re-attach the stand using the original
bolts.
Inner Race
Wider on Top
Side
7. Attach the auger to the top bearing and
breaker.
8. Return the auger to the evaporator and
slide it down until the splines touch the
coupling.
Sealant
Here
Rubber
Smooth
Side
Outer
Race
Water Seal
Open
Sides
9. Rotate the auger until the coupling
splines align with the auger.
10. Push the auger down, and rotate the
breaker until the screw holes line up with
the pilot holes in the evaporator.
11. When the auger is completely seated,
reinstall the breaker screws.
12. Replace permagum and foam top.
13. Switch on the water supply.
14. Check bin cover for electrical grounds
and switch on the electrical power.
15. Observe operation. The unit should
make minimal noise while producing ice.
Catch first 2 minutes of ice and discard it.
16. Replace the bin cover and all panels.
May 2001
Page 25
MDT3F & MDT4F
Refrigeration System
This ice machine uses R-134a as the
refrigerant. This refrigerant has no chlorine,
and therefore requires polyolester type
refrigerant oil. This oil requires specific service
procedures.
General Service
A HFC type liquid line drier is required. “Standard”
driers may not take out enough moisture and may
affect the oil additives.
The time that the refrigeration system is open to
the air must not exceed 15 minutes. The oil will
rapidly absorb moisture from the air, and the
contact time must be kept to a minimum.
A special or very sensitive electronic leak detector
will be needed to locate refrigerant leaks. Many are
on the market that will sense R-134a.
The access valves must be in the closed position
before the hose caps are removed. Do not remove
the hose caps before checking the position of the
valve. Use a 3/16" allen wrench to open and close
the valve.
Torque Stem to
6-8 ft. lb.
Access Valve
As with any other refrigerant, do not place
pressurized air or oxygen into the refrigeration
system.
Note: The refrigeration system uses an HFC
type refrigerant and MUST use an HFC type
drier.
Stem Cap
Torque to 8-12 ft. lb.
Fitting Cap
Torque to 7-12 ft. lb.
Temperature Pressure Chart, Selected Points
Temperature in0F. PSIG of R-134a
-10 2.0
-6 3.7
-4 4.6
-2 5.5
0 6.5
1 7.0
2 7.5
3 8.0
4 8.6
5 9.1
10 12.0
12 13.2
14 14.4
16 15.7
18 17.1
20 18.4
25 22.1
30 26.1
31 26.9
32 27.8
33 28.6
34 29.5
35 30.4
40 35.0
45 40.0
50 45.4
75 78.7
90 104.3
110 146.4
120 171.1
130 198.7
150 262.8
Evacuation to 300 microns is recommended.
May 2001
Page 26
Gear Reducer Removal
MDT3F & MDT4F
1. Disconnect electrical power.
Electrical Shock Hazard
Disconnect electrical
power before beginning.
2. Shut off the water supply.
3. Remove the top and side panels.
4. Remove the control box cover.
5. Remove the centrifugal switch cover on the top
of the auger drive motor.
6. Disconnect the electrical wires from the
centrifugal switch.
7. Drain the evaporator and reservoir.
8. Disconnect the water inlet tube from the
evaporator.
9. Remove the three screws holding the evaporator
to the adapter stand.
10. Lift the evaporator up high enough for the
auger to clear the adapter stand.
11. Remove the mounting bolts holding the gear
reducer to the cabinet frame.
12. Trace auger drive motor wires back to the
control box.
13. Disconnect the drive motor wires from the relay
on the circuit board.
14. Pull the wires back to the auger drive motor.
15. Pull the gear reducer out the side of the cabinet
to remove it from the machine.
Note: If there is evidence of water near the output
shaft of the gear reducer, it would be a wise
precaution to pull the auger from the evaporator
and check the bearings.
16. Rebuild or replace the gear reducer.
Rotor Cover &
Bearing
Fan
Stator
Rotor
Rotor
Bearing
Shaft Seals
E-Clip
Woodruff Key
Output Gear
Gear Reducer Components
Gear Case
May 2001
Page 27
MDT3F & MDT4F
Auger Drive Motor
The windings or top bearing & cover may be
replaced without removing the evaporator or gear
reducer from the machine.
1. Disconnect electrical power.
Electrical Shock Hazard
Disconnect electrical
power before beginning.
2. Shut off water supply.
3. Remove top panel.
4. Remove right side panel.
5. Drain the reservoir and evaporator.
6. Disconnect the reservoir outlet tube from the
bottom of the reservoir.
7. Remove screws holding reservoir mounting
bracket to the cabinet.
8. Lift the reservoir up & away from the top of the
auger drive motor.
If the rotor needs to be removed:
1. Run a screw into the top of the rotor.
2. Grasp the screw with a grip pliers.
3. Pull and/or tap on the pliers to pull the rotor &
bearing out of the gear reducer.
4. Inspect the bearing and input seal. Replace
them if worn.
Note: When the rotor is re-installed, be certain that
the bearing is fully seated in the gear case.
Gear Reducer Rebuild
1. After the gear reducer has been removed, the
internal components may be inspected and/or
replaced. Remove all bolts holding the two case
halves together.
2. Tap against the roll pins at each end of the gear
cases to split them.
3. Pry the case halves apart.
4. Check the internal condition of the gear reducer.
If rusty or water is present, replace the complete
assembly. The oil should be black and the proper
oil level is 1/8" from the top of the biggest gear
(with all gears installed). Check the input seal.
The gears may be replaced individually.
9. Remove the 4 bolts holding the auger motor
cover to the gear reducer case.
10. Lift the plastic switch housing off the auger
drive motor.
11. Hold the centrifugal switch and remove the
screw holding it to the rotor of the motor.
12. Lift the centrifugal switch up and off the motor.
13. Lift the motor cover up and off the motor.
14. Pull the fan up and off the rotor.
If the windings are to be replaced, remove the left
side panel and control box cover.
1. Locate the auger drive motor wires plugged into
a relay on the circuit board.
2. Disconnect the auger motor’s wires and pull
them back to the auger drive motor.
3. Lift the auger motor windings off the gear
reducer.
May 2001
Page 28
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