Technical Manual for Model UF424 and UN324

Technical Manual for
Model UF424 and UN324
UF424 / UN324 Technical Manual
Introduction
To the owner or user: the service manual is intended
to provide you and the maintenance or service
technician with the information needed to install,
startup, clean, maintain and repair this product.
Observe any caution or warning notices. They are
important and provide notice of potential hazards.
Keep this manual for future reference.
If additional technical information is needed, go to
Scotsman’s website, www.scotsman-ice.com.
Note: This is a commercial product. If service is
needed on a unit in a residence, warranty may be
limited. Use a commercial service company. Locate
one from the Scotsman website: www.Scotsman-ice.
com
Table of Contents
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cabinet Drawing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Plan and Front Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Side and Back Views. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operational Data . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Placement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Initial Start up. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Maintenance and Cleaning. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Condensers and Air Filter Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Basic Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controller Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controller Details . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Controller Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing Compressor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replace Compressor. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Replace Fan Motor . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Testing Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Panel Removal . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Remove Ice Storage Bin. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Remove Gear Reducer. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Remove Auger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replace Evaporator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replace Auger Motor. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
Prep to Replace Water Seal or Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replace Water Seal and Auger Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replace Electrical Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Diagram. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
September 2017
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UF424 / UN324 Technical Manual
Specifications
This ice maker is designed to be installed indoors,
in a controlled environment. Although it can operate
in a wide range of air and water temperatures, it
will provide the best performance if not subject to
extremes.
Air Temperature Limitations
o
Maximum: 100 F or 38 C
•
Minimum: 50 F or 10 C
o
o
Water Temperature Limitations
o
o
•
Maximum: 100 F or 38 C
•
Minimum: 40 F or 4.4 C
o
o
Water Pressure, Potable
•
Maximum: 80 PSI or 5.5 BAR
•
Minimum: 20 PSI or 1.3 BAR
Warranty Information
The warranty statement for this product is provided
separately from this manual. Refer to it for applicable
coverage. In general warranty covers defects
in material or workmanship. It does not cover
maintenance, corrections to installations, or situations
when the machine is operated in circumstances that
exceed the limitations printed above.
o
•
Operating the machine outside of any of the above
limitations is considered abuse and any resulting
damage is not covered by warranty and could cause a
complete loss of warranty coverage.
Product Information:
•
Maximum: 145 PSI or 10 BAR
The UF424 produces flaked ice and the UN324
produces nugget ice. The ice is stored in an insulated
bin with ice level automatically maintained by the
control system.
•
Minimum: 20 PSI or 1.3 BAR; can be as low as
o
5 PSI or 0.3 BAR if clean and supplied with 45 F
water.
A back flow preventer may be required by local
plumbing codes.
Water Pressure, Condenser inlet
Condenser GPM
•
•
o
Has a 5.5 ft. power cord with NEMA 5-15P plug.
o
70 F or 21 C water: 0.25 GPM or 0.95 LPM
o
o
50 F or 10 C water: 0.15 GPM or 0.57 LPM
Voltage 115 volt models
•
Maximum 126 VAC
•
Minimum 104 VAC
Legs are provided, thread size is 5/8-11. Replacement
leg kit number is KLP7.
Machine may be installed without legs.
For available options and kits, see sales literature.
Water Conductivity:
•
Air cooled models flows in the right front and out the
left front and include a cleanable air filter.
Minimum:10 micro Siemens/CM
RO water may be supplied to the potable water
system, but if it has less than the above conductivity,
the water level sensor will not detect water and the
unit will not make ice.
Scotsman Ice Systems are designed and
manufactured with the highest regard for safety and
performance. They meet or exceed UL563, verified by
Intertek, ETL.
Deionized water is not recommended due to its
potential corrosive nature and any damage caused by
DI water will not be covered by warranty.
September 2017
Page 3
UF424 / UN324 Technical Manual
Cabinet Drawing
WATER INLET
ACCESS
POWER
CORD
DRAIN
September 2017
Page 4
UF424 / UN324 Technical Manual
Plan and Front Views
72.3cm
28.4in
61cm
24.0in
84.7cm
33.4in
99cm
39.0in
50.8cm
20.0in
AIR
EXHAUST
AIR
INLET
September 2017
Page 5
UF424 / UN324 Technical Manual
Side and Back Views
5.3cm
2.08in
UTILITY
CLEARANCE
72.8cm
28.7in
15.1cm
6.0in
51.4cm
20.3in
UNIT DRAIN
3/4" FPT
WATER INLET
3/8 FLARE
CONDENSER WATER
INLET 3/8-18NPT
CONDENSOR
WATER DRAIN
CONNECTION
1/2-14 NPT
11.9cm
4.7in
POWER
CORD
WATER REGULATOR
ADJUSTMENT ACCESS
17.5cm
6.9in
24.5cm
9.7in
September 2017
Page 6
7.8cm
3.1in
13.6cm
5.4in
16.8cm
6.6in
UF424 / UN324 Technical Manual
Operational Data
Model
High Pressure
Switch (PSIG)
Electrical
(Volts/Hz/Phase)
Condenser
Cut Out Cut In
UF424A-1A / UN324A-1A
UF424W-1A / UN324W-1A
UF424A-6A / UN324A-6A
115/60/1
115/60/1
230/50/1
Air
Water
Air
260
260
260
Model
UF424A-1A / UN324A-1A
UF424W-1A / UN324W-1A
UF424A-6A / UN324A-6A
Typical Watts
560 - 690
540 - 575
Model
Condenser
70/50 Suction
Pressure
(PSIG)
90/70 Suction
Pressure
(PSIG)
UF424A-1A / UN324A-1A
UF424W-1A / UN324W-1A
Air
Water
6-8
6-8
8-9
6-8
Typical Amps
6.3 - 7
6.1 - 6.7
190
190
190
Refrigerant
Charge
(R-134a)
Ounces
Maximum Fuse Size
or Breaker (Amps)
12
12
15
15
Auger Motor Amps
1.1 - 1.4
1.1 - 1.4
70/50
Discharge
Pressure
(PSIG)
130-135
135
Compressor Amps
5 - 5.8
5 - 5.8
90/70
Discharge
Pressure
(PSIG)
180 - 185
135
Note: 70/50 and 90/70 refer to the air and water temperatures (in degrees F) the machine was tested in. All
field conditions are unique, but at temperatures near those listed a field machine will have similar results.
September 2017
Page 7
UF424 / UN324 Technical Manual
Placement
The location of the equipment should be selected
with care. Consideration should be given to allow
adequate space for air cooled models to breathe.
The power outlet should be located within the length
of the supplied power cord. If legs will be used, allow
space for the total cabinet height.
The ice machine is not designed for outdoor
use. It must be installed indoors, in a controlled
environment. The air and water temperatures must
not exceed rated limits.
Air cooled models in a small room will require
ventilation to exhaust heat from the condenser. The
condenser fan and motor will generate some noise
while the machine is running. Noise sensitive areas
should consider water cooled equipment or locate
the machine where the noise from ice making will not
objectionable.
Scotsman assumes no liability or responsibility of
any kind from products manufactured by Scotsman
that have been altered in any way, including the use
of any part and/or other components not specifically
approved by Scotsman.
Scotsman reserves the right to make design changes
and/or improvements at any time.
Specifications and design are subject to change
without notice.
Airflow on air cooled models:
Intake from the right grill
Exhaust from the left grill
Do not install where this air flow is blocked.
Unpack
1. Separate the carton from the shipping pallet
2. Inspect for any hidden shipping damage. If any
is found, retain carton and notify carrier for potential
claim. Shipping damage is not covered by warranty.
Caution: Tip Over hazard to prevent injury or
damage to the machine please use caution when
lifting the unit. It will easily tips to the rear.
3. Remove bolts holding machine to pallet.
4. Install the legs. The legs are to be screwed into the
same holes the shipping bolts were removed.
5. Remove the protective plastic covering the panels.
The longer it is left on the panel, the more difficult it
will be to remove it.
Spacing:
No additional spacing is required at the top or sides.
However, suggested minimum side clearance for the
installation is 1/8’’ or 3.2 mm and suggested minimum
top clearance is 1/4” or 6.4 mm.
The machine may be installed with 0 clearance at the
back. Do not block louvers at the front of the cabinet.
Pre Installation:
Water supplied to the ice machine should be filtered.
Install a filter system that filters out suspended solids.
It may be necessary to add a coarse pre-filter ahead
of the fine filter.
Inspect the place where the ice machine is to be
installed. Check for:
Airflow
•
Space for the cabinet
•
Water Supply
•
Drain Availability
•
Electrical Power Supply
September 2017
Page 8
UF424 / UN324 Technical Manual
Installation
Note: The building drain inlet must be lower than
the drain outlets at the back of the ice machine.
The water supply must have a hand shut off valve
accessible when the unit is installed.
For the Plumber
1. Connect cold potable water to the 3/8’’ male
flare behind the lower back panel. A water
filter is recommended. Flush the water line
prior to connecting to the ice machine.
A loop of copper tubing may be used between the ice
machine and the water supply. This will allow the ice
machine to be pulled out from its installed location
without disconnecting water. No back flow preventer is
required in the potable water line. This is provided by
the reservoir seat, which is above the reservoir water
level and cannot be siphoned
2. Connect a drain tube to the drain fitting. Drain
tubes for a water cooled machine should be
run separately. The bin drain fitting is 3/4’’
FPT. And it is plastic. Do not overheat.
• Drain tube material must be rigid and meet
local code.
• Traps in the bin drain line without vents
ahead of them will cause poor draining
• The bin drain must be vented if there is a
long horizontal run 5 feet or more. All drains
are gravity and must have a minimum fall of
1/4’’ per foot of horizontal run.
• Maintain the air gap required by local code
between the end of the drain to, and the
building drain receptacle.
• Drain tubing should be insulated to prevent
condensation from forming on the tubing.
For the Electrician
This is a cord-connected unit and must be on a
separate single phase power supply. Check the name
plate for the correct voltage. The maximum fuse size
for this circuit should be 15 A, per the nameplate use
fuses or HACR circuit breaker.
Follow all local codes. This unit must be
grounded. Do not use extension cords and
do not disable or bypass the ground pin on
electrical plug.
After utility connections
1. Level the cabinet, use the leg levelers on
the end of the legs to adjust to cabinet height.
Legs should have been installed when the unit
was unpacked.
2. Wash the bin and hood. If desired, the interior
of the bin could be sanitized.
3. Locate the scoop, wash it and have it
available for use when needed.
Water
Inlet
3. Water cooled models have a separate 3/8”
FPT fitting for condenser water inlet. DO
NOT FILTER water to this connection. The
condenser drain is1/2’’ FPT and does not
need a vent.
Drain
Utility Connections
September 2017
Page 9
UF424 / UN324 Technical Manual
Initial Start up
Final check list:
Ice machine is installed indoors with air
and water temperature controlled within
the limitations detailed in this manual
Ice machine is level in its final position
Electrical disconnect (switch or plug as
required) is within sight of the installed
machine
Electrical circuit is dedicated to this ice
maker
Voltage has been confirmed within the
specifications in this manual and the name
plate on the ice maker
Plumbing connections are complete and
tested for leaks
Ice maker is installed with proper
clearance, allowing for service and utility
connections
Water shut off valve installed near the ice
maker
Start up:
1. Remove louvered front panel.
2. Open bin door and remove the inner panel, held in
place by 4 thumb screws.
3. Open the water valve. Observe that water enters
the water reservoir, fills and then shuts off. Check
for leaks. Repair any leaks before going further.
4. Switch electrical supply on. Lights on controller
will flash and then the power light will remain on.
The code display will show O.
5. Push and release the On/Off button. The machine
will start the ice making process. The code display
will show F. Air cooled models will discharge
warm air out the left side of the front panel.
Water cooled models will discharge warm (about
1200F/480C) water out of the condenser drain. In
a few minutes, ice will begin to fall into the bin.
7. Create a solution of sanitizer. Mix 4oz/118ml of
NuCalgon IMS III and 2.5gal/9.5L of (900F/320C
to 1100F/430C) potable water to create a 200 ppm
solution.
8. Sanitize bin by wiping all surface areas with the
sanitizer solution. Allow to air dry.
9. Turn the ice maker on by pressing the on button.
10.Replace inner panel, front cover and louvered
panel.
11.Give the owner/user this manual, instruct him/her
in the operation and maintenance requirements
of the unit. Make sure they know who to call for
service.
Fill out the Customer Evaluation and Warranty
Registration form, and mail it in to Scotsman or
register the unit at Scotsman’s website (www.
scotsman-ice.com).
Once started, the ice machine will automatically
make ice until the bin level sensors are blocked.
This will happen once the ice piles up to the sensors.
The typical ice level when the machine is off will be
several inches below the door. When ice level drops
from use or meltage, the ice machine will resume
making ice.
Tip: To maximize ice storage scoop the ice to the
sides of the bin.
Noise:
This is a commercial ice machine. It contains a
powerful compressor, heavy duty gear reducer and,
if air cooled, a fan motor. It will produce some noise
when it is making ice. Every effort was made during
its design to minimize the sound level but some is
unavoidable.
6. Push the on/off button to switch the machine off.
Scoop out any ice in the bin.
September 2017
Page 10
UF424 / UN324 Technical Manual
Maintenance and Cleaning
There are 4 areas of maintenance
1. Ice making system
2. Photo eye ice level control system
3. Bin
4. Air cooled condenser and filters
Ice making System:
Remove Scale
Reservoir
1. Remove front panel.
2. Turn the machine off by pressing the on / off
button.
5. Remove the top cover from the reservoir.
6. Shut water supply off at the reservoir by turning
the knob counterclockwise.
Knob
3. Empty the ice from the storage bin
4. Remove the inner panel using the 4 thumb
screws.
Inner Panel
7. Locate the evaporator drain in the ice machine
compartment. Unplug it and drain the evaporator.
8. Replug the drain.
9. Mix a solution of 1.5qt/1.4L of warm water
(900F/320C to 1100F/430C) and 4 ounces of
Scotsman Clear 1 Ice Machine Scale Remover.
Ice machine cleaner contains
acids. Acids can cause burns.
If concentrated cleaner comes
in contact with skin, flush with
water. If swallowed, do NOT
induce vomiting. Give large
amounts of water or milk. Call
physician immediately. Keep
out of the reach of children.
September 2017
Page 11
UF424 / UN324 Technical Manual
10.Pour the cleaning solution into the reservoir until
it is full (a squirt bottle may be necessary to fill
reservoir with cleaning solution).
Sanitize Water System
1. Create a solution of sanitizer. Mix 4oz/118ml of
NuCalgon IMS III and 2.5gal/9.5L of (900F/320C to
1100F/430C ) potable water to create a 200 ppm
solution.
2. Pour the sanitizing solution into the reservoir until
it is full and wait 2 minutes.
3. Turn on the water supply and press the ON /Off
button to turn the ice machine on
4. Operate the machine for at least 15 minutes.
5. Drain the solution from the system by pulling the
reservoir plug from the drain hose. Return plug
when drained.
Photo Eye ice level control
11.Push the clean button. The machine will operate
the auger motor for approximately 20 minutes.
Then it will start making ice with the cleaning
solution.
12.Add remaining cleaning solution to the reservoir
as ice is being made for the next 20 minutes. After
the full 40 minutes (steps 11 & 12) the unit turn off.
13.Drain the solution from the reservoir by removing
the plug. Once drained, replace the plug.
14.Pour clean water into the bin to melt any ice
produced during the cleaning cycle.
15.Mix a solution of 4oz/118ml of Scotsman Clear
1 ice machine scale remover and 16oz/473ml of
potable water. Use this scale remover solution for
the water reservoir cover, ice discharge chutes,
the storage bin and the inner front cover.
1. Mix solution of 4 ounces of Clear 1 Ice Machine
Scale Remover and 1.5qt/1.4L of 900F/320C to
1100F/430C water.
2. Remove sensors from inner cover by removing
the white c-clip .
3. Use cotton swab and cleaning solution to
thoroughly clean photo sensors.
4. Rinse sensors with clean water.
5. Reinstall sensors in inner panel.
Bin
1. Use the same cleaning mixture to thoroughly
clean bin surfaces.
2. Rinse with clean water.
3. Use sanitizer mix on all bin surface areas and
areas that may contact the ice.
4. Rinse with clean water.
September 2017
Page 12
UF424 / UN324 Technical Manual
Condensers and Air Filter Cleaning
Filters and Air Cooled Condenser
The air filter located on the lower front grill will capture
airborne dust during operation. As the dirt builds up, it
begins to restrict air flow and causes the refrigeration
system to work less efficiently. Clean the air filter
regularly.
1. Remove the filter by sliding it to the right until it
is clear of the ice machine.
Note: It is a snap fit and the snaps may be very tight.
Pull hard with two thumbs.
2. Remove dust and dirt by washing the filter in a
utility sink.
3. Reinstall filter in the ice machine.
Condenser
The condenser fins require semi annual cleaning. Use
caution to prevent damage to the condenser fins.
1. Lightly brush dust from the condenser.
2. Use a vacuum to thoroughly clean the
condenser.
Water cooled equipment may be connected to a
closed loop recirculating system or to a regular water
supply. See the pressure limits on page 3.
The included water regulating valve will vary the
amount of water or coolant needed to maintain
a constant discharge pressure. Higher coolant
temperatures will result in increased coolant flow to
maintain the discharge pressure set point.
That pressure is factory set to 135 PSIG. If needed, it
may be field adjusted to that set point. An access port
to the adjustment stem is available on the lower back
panel.
In areas with highly mineralized water, the inside
of the condenser may become coated with scale.
When that occurs the amount of water used by the
condenser will increase, as the water regulating valve
opens further to keep the discharge pressure at the
set point.
Scale on the inside of the condenser may be cleaned
by circulating an acid solution with an auxiliary pump.
Air Filter
Remove and Clean the Air Filter
September 2017
Page 13
UF424 / UN324 Technical Manual
Operation
At initial start up there is no ice in the ice storage bin, so there is nothing blocking the infrared sensors that are
used to control the on or off mode of the machine. A push of the on off button triggers the controller to begin ice
making.
The controller checks for water using the continuity sensor in the reservoir. If that sensor indicates there is
water, and the refrigeration pressure switch is closed, the controller connects power to the compressor, fan
motor (if air cooled) and auger drive motor.
The compressor forces refrigerant to circulate causing the evaporator to become very cold, which takes heat
from the water inside the evaporator’s tube. That refrigerated space also contains the slowly rotating auger.
Eventually enough heat is removed from the water to cause ice crystals to form. When enough ice crystals
have formed the auger moves them vertically up the tube and the soft, wet ice is forced through the slots in
the ice breaker. The limited area of the slots causes the soft ice to be forced together, forming either flaked or
nugget ice, depending upon the design of the breaker. As ice exits the breaker or extruder, more water flows
from the reservoir into the bottom of the evaporator tube.
Water replenishment by the gravity fed water is the key element in this ice making process. It provides a
continuous heat load to the refrigeration system so that, as ice is made, an equal amount of water re-enters the
system, keeping the system in balance. A flaker then, is a unique refrigeration system in that it is steady-state.
Once the machine has begun to make ice the evaporator’s temperature does not change as the replenished
water keeps adding heat.
The ice slides down a chute into the insulated bin. The bin is not refrigerated. There is a drain at the bin’s floor
to let melt water out. As it is made, ice will pyramid under the chute and form a pile that gradually increases to
the point that the top of the pile enters the chute, blocking the infrared light between the ice sensor’s emitter
and receiver, which signals the controller to stop making ice. The ice level at the first shut off may be less than
later when the bin temperature has stabilized. Ice storage bin capacities are calculated by the bin’s internal
volume, so the amount of available ice may not equal the calculated quantity unless ice is distributed to the
sides during use.
The shut off process begins when the controller opens the compressor relay, cutting the power to the
compressor. The auger motor continues to operate to clear the evaporator tube of any ice that was in it. Then it
is shut off. In normal operation when the ice is used or melts enough to expose the emitted infrared light to the
sensor’s receiver, and the compressor has been off for the preset amount of time, ice making will restart.
Sound
The normal sounds of this machine are the compressor, fan blade if air cooled, and auger drive motor.
Occasionally there may be a slight crunching sound as ice is forced thru the extruder or breaker. A loud
moaning noise could occur if ice is not sliding vertically up the evaporator tube. If it revolves with the auger,
it will remain under refrigeration too long, and could even freeze to the evaporator wall. Then it becomes like
chipped ice, which causes the gear reducer to be overloaded as it pushes the extra hard ice thru the extruder.
That is known as a rotating freeze. The most likely cause of a rotating freeze is internal scale build up,
especially on the auger.
September 2017
Page 14
UF424 / UN324 Technical Manual
Basic Troubleshooting
Symptom
No ice in bin
Possible Cause
Unit in off mode or off on
error code.
Probable Correction
Remove front panel and check controller code
display. Push ON/OFF button to reset. See pages
16 and 17 for further details.
False bin full
b is showing in the display but the bin is not full.
Check that there is good connection from the
controller to the photo eye set. Replace photo eye
set if no other cause can be found.
Check for the power light on the controller. If not
illuminated restore power.
No power to unit
Auger motor not operating
Compressor not operating
Excessive noise
Moaning noise when
making ice
Slow or Low production
Unit cycles off and
restarts
Compressor operating,
auger turning, no ice is
made
Tubing contact
Fan blade out of balance
Compressor noisy
Water seal being
compressed
Air filter is dirty
Condenser is dirty
Room and/or Water
Temperature too high
Restricted air flow to unit
Loose electrical connection
Open windings. Check motor windings and replace
if open.
Gear reducer seized, replace gear reducer.
Auger bearings seized, replace bearings and seal
No power to auger motor, Auger light is ON.
Replace controller.
Code 2 in controller. Check that sensor rotates with
motor and isn’t loose. Tighten screw if loose.
Code 1 in controller, replace auger motor.
Contactor coil is open, check and replace if needed.
Compressor hot and overheated, check start relay
and start capacitor. Check system charge. Check
TXV for high superheat.
No power to compressor or contactor coil.
Compressor light is ON. Replace controller.
Compressor at room temperature, will not start.
Check windings. If open, replace compressor. If not
open, check/replace start relay and start capacitor.
Check refrigeration system, TXV may be set to too
much superheat or the system is low on refrigerant.
Check for tubes rattling and panels not tight
Replace fan blade
Replace compressor
Gear reducer bearing failure, replace gear reducer
Clean air filter
Check and clean condenser
Maximum production will be achieved at 70°F / 21°C
air and 50° / 10°C water
Check and remove air flow restrictions
Check power cord and outlet. Outlet may be worn,
replace worn outlet.
Note: A damaged power cord must be replaced by the identical, OEM service part.
September 2017
Page 15
UF424 / UN324 Technical Manual
Controller Functions
All models use the same control system.
There is also a code display, the codes are:
The electronic controller operates the compressor
(with fan motor), and auger drive motor, It monitors:
• Reservoir water availability
• Storage bin ice level
• Refrigeration pressure
• Auger motor speed
• Auger motor rotation
Many of these are used to insure that the machine
does not damage itself during use. For example, it is
critical that it not attempt to make ice without water, so
if the water sensor is dry, the machine will not make
ice.
Switches - there are two switches:
• On/Off - to switch the machine on or off. Holding it
in to shut off will stop ice making immediately.
O - - - F - - - b - - - E - - - C - - - d - - - 1 - - - 2 - - - 3 - - - 4 - - - for off
for ice making
for bin full
for controller error
for clean mode
for test mode
for auger rotation direction wrong
for auger speed too slow
for no water sensed
for high refrigerant pressure
If a number code is triggered, the controller will stop
ice making. A blinking code means it is a temporary
condition. Example: A blinking F occurs during the
ice making restart process; it stops blinking when the
compressor starts.
The controller will automatically restart from a water
interruption or power interruption or when a refrigerant
pressure switch has automatically reset.
• Clean - to engage the clean mode
Indicators - there are five LEDs:
• Power - Glows when controller has power
• Status - Glows when in ice making mode
• Time to Clean - Glows when it is time to clean the
machine
• Auger - glows when the auger motor is on
To reset the control when it has been manually locked
out, Push and release the On/Off button to shut it Off
and then Push and release it again to switch it On.
Note: The compressor will not restart for 2 minutes
from the time it was shut off.
• Compressor - glows when the compressor is on
September 2017
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UF424 / UN324 Technical Manual
Controller Details
The controller has features for the service technician. Some details:
• Any auger motor failure is an immediate shut down. Because of the critical nature of that failure there is no
auto restart from an auger error.
• An open Water Sensor (dry probes) will stop the machine. Because water can be restored at any time,
whenever both Water Sensor probes are wet again AND the compressor has been off for at least two minutes,
ice making will restart.
• An open High Pressure switch will stop the machine. Because the pressure switch is an automatic reset,
when it closes AND the compressor has been off for at least two minutes, ice making will restart.
• Fault Code View: Push and HOLD the clean button (auger motor starts) AND then push and release the
on/off button 3 times (auger motor stops) or until Status light is on. Release both. Pushing Clean will cycle
thru the available codes, the total number of codes stored is 30.
Note: An existing error cause will not allow the fault codes to be read. Example: No water in the reservoir will
trigger an immediate code 3 and any other codes cannot be read. Either correct the cause or jump out the
sensor signaling the error and then go thru the Fault Codes View process.
• Clear codes: Only from Fault Code View: Push and HOLD the Clean button for about 3 seconds. The
display code will blink 3 times. Release.
• The compressor will not restart until it has been off for at least 2 minutes.
• There is a Test Mode. The Test Mode operates each load in sequence to confirm that it is being powered
by the controller.
To start Test Mode: Push and HOLD the ON/OFF button; at the same time, push and HOLD the CLEAN button.
When a “d” appears in the code display, release the buttons, the test mode will begin.
Time (seconds)
0
10
20
20
40
On
Compressor
Compressor and Auger Gear Motor
Auger Gear Motor
None
None
Off
Auger Gear Motor
Compressor
Auger Gear Motor, Compressor
All – Test Complete
• The Time to Clean indicator light glows when 6 months of power up time have elapsed. When it is on it
does NOT stop ice making. It is cleared and reset when the Cleaning process has been completed.
• The Cleaning process, described in detail in the Maintenance section, is initiated by a press of the Clean
button. The auger motor will be operating during the entire Clean mode, the compressor starts automatically
to make ice with the scale remover solution. The scale is dissolved by the action of the scale remover solution
and the auger’s motion.
• USB firmware updates may become available. To update the unit must be in Test Mode and then a USB
stick with ONLY the update on it is inserted into the USB connector. L will be displayed during the Loading
process. After a few seconds the LEDs begin scrolling up for about 75 seconds then the LEDs start scrolling
down for about 20 seconds. At the end “0” is displayed. Unplug the USB drive.
Note: If during the update process the display flashes between “L” and “F” that means that the Load Failed. If
that happens, unplug the USB drive, then power cycle the control board. If “0” is not displayed, press the On/
Off button. The controller will revert to the original firmware.
September 2017
Page 17
UF424 / UN324 Technical Manual
Controller Diagnostics
Code or Light Action
O
Probable Cause
Unit manually switched off
Suggested Action
If desired, switch unit on.
F
Freeze mode
None, unit is making ice.
b
Bin sensors sense bin full
Check if bin is full.
E
Corrupted memory
Replace controller
C
Clean mode
Continue clean mode
d
Test mode
1
Auger motor rotated auger
backwards.
2
Auger motor stalled or operating
slowly
None, allow unit to finish test
mode.
Replace auger motor. Check water
seal area for leaks, replace seal if
leaking.
Clean ice making system and retry.
3
No water in reservoir
4
High pressure cut out open
Status light is on
Unit is in ice making mode
Time to Clean light is on
Unit has not been cleaned for at
least 6 months
Auger light is on
Auger motor is active
Normal when making ice
Compressor light is on
Compressor is active
Normal when making ice
Code E cannot be corrected in the field. Replace controller.
September 2017
Page 18
If unit shuts off again right after a
reset, magnet rotor on motor shaft
may be loose.
Restore water. If there is water,
is it too pure? Are sensor wires
connected?
Check fan motor on air cooled or
water supply on water cooled.
Normal, may not be making ice if
bin is full
Clean unit
UF424 / UN324 Technical Manual
Electrical Sequence
When electrical power is connected, and the prior
mode was Off, the controller verifies the voltage and
performs a self check. If the self check confirms the
controller is working and that water is sensed in the
reservoir, it will display an O and blink the Status light.
If the prior mode was ice making, the controller will
also perform a self check, when it is successful it will
begin a restart process and display F.
Timings
If no water is sensed, the controller will not allow
ice making, but instead a 3 will show in the display,
indicating that no water has been sensed. When
water is sensed, and the bin control is calling for ice
and at least two minutes have passed, the controller
will automatically start ice making.
Note: A failure of the self check will result in the
controller displaying an E and no other action will
occur.
•
Status changes from Bin Full to Bin Empty: 10
second delay.
•
Status changes from Bin Empty to Bin Full. 6
second delay
•
Auger motor on after bin full or timed shut down:
60 seconds.
•
Compressor restart after off: 2 minutes.
•
Hi pressure control reset time: Varies by ambient
and cabinet temperature. Longer in high
temperatures.
•
Clean mode: 20 minutes of auger only operation
and then 20 minutes of auger and compressor
operation. 40 minutes total.
After a successful restart, the controller will switch on
the compressor and auger motor to begin ice making.
The controller’s compressor relay supplies power to
the contactor coil while the auger motor’s power is
supplied directly from the controller’s auger relay. If
the unit is air cooled, the fan motor will also start, as it
is electrically tied to the compressor contactor.
Ice making continues until the infrared light is blocked
and the unit shuts down on bin full. It can also stop
from any of these safeties:
1. Hi pressure cut out: 230 PSIG, automatic reset
when the pressure drops to 190 PSIG. If triggered,
it signals a severe condition where there was
either no fan blade rotation on air cooled models
or no water supplied to water cooled models.
2. Auger motor overload. Immediate shut down,
manual reset. This signals a condition where the
auger motor could not rotate the auger at the
correct current.
3. Auger motor reversal. Immediate shut down,
manual reset. Auger motor failure.
Manual reset - restart process: Push and release the
On/Off button, unit will display O. To restart: push and
release the On/Off button again.
Manually shut down either by pushing and releasing
the On/Off button (compressor shuts off, auger motor
continues for a minute) or by holding in the On/Off
button until the machine completely stops.
September 2017
Page 19
UF424 / UN324 Technical Manual
Testing Compressor
The refrigeration system is steady-state. When
in operation and stabilized, it will maintain nearly
constant discharge and suction pressures.
Capacitor Testing
Items that can affect that are:
Capacitors may be tested using a multimeter, but
begin with a visual test. A good indication of a failed
capacitor is one that is bulging or leaking.
•
Irregular water flow
If the capacitor looks ok, check it with a multimeter.
•
Erratic thermostatic expansion valve
1. Discharge the capacitor.
•
Changes in room air temperature
2. Set a digital meter to a high resistance scale of at
least 4k.
Normally use of refrigeration gauges is unnecessary.
If the unit is making ice properly, it is highly likely that
all is normal. Refrain from attaching gauges, and
then only use very short hoses to avoid changing
the amount of refrigerant charge. See pressure
information on page 7.
Electrical Shock Hazard
Disconnect electrical
power before beginning
The compressor gets its power from the contactor,
which is operated by the controller. It must be working
or the compressor will be off.
Compressor Starting
The compressor uses a potential relay and start
capacitor to provide starting power.
Potential relay: The contacts of this relay are normally
closed and open when the compressor starts.
Compressor starts but current too high, overheats. If
the relay contacts do not open, there will be current
from the start capacitor. Replace the relay.
Compressor does not start. Relay contacts open,
check for continuity. Replace relay if open. Start
capacitor may have failed.
3. Put the probes on the capacitor terminals and
observe the display. It should provide a reading
and then show Open Line. If no reading, the
capacitor has failed and should be replaced.
If the meter has a Capacitance setting, use it to
measure the capacitance, replace if not near to the
mfd listed on it.
Compressor Testing
Because the compressor is the hermetic type, the
available testing methods are limited. Some items that
can be measured are winding resistance and amp
draw.
If the compressor does not start and a check with an
amp meter shows it does not draw any current, it is
likely it has an open winding or overload. Those can
be checked using a multimeter.
If the compressor is hot the overload may be open. An
open overload is an indication of a worn compressor,
defective starting components or high superheat.
Note: Normal operating temperature of the
compressor dome is 85 - 95 degrees F. - warm to the
touch.
If the overload is open and the compressor is not hot,
the overload itself could be the problem. Overloads
also open due to high current and a shorted winding
could cause that. Check for shorted or grounded
windings with a multimeter.
High superheat is caused by lack of refrigeration,
possibly from low charge or a TXV starving the
evaporator.
September 2017
Page 20
UF424 / UN324 Technical Manual
Replace Compressor
The compressor can be replaced from the back.
Note: Always check electrical information on new
compressor to be sure it is the correct voltage and
phase.
1. Disconnect electrical power.
Electrical Shock Hazard
Disconnect electrical
power before beginning
2. Remove lower back panel.
3. Disconnect wires from compressor terminals.
4. Recover refrigerant from the unit.
5. Remove hair pins holding compressor to chassis.
6. Disconnect suction, discharge and process tubes
from compressor.
7. Remove compressor from unit.
8. Install new compressor in unit.
9. Reconnect suction, discharge and process tubes
using the proper techniques of the refrigeration
trade.
10.Remove and replace the dryer.
11.Attach a vacuum pump with micron gage to the
system and evacuate it to 300 microns.
12.Reattach electrical wires to compressor terminals.
13.Replace the relay and capacitors with those from
the kit.
14.Weigh in the nameplate charge.
September 2017
Page 21
UF424 / UN324 Technical Manual
Replace Fan Motor
Suggested tools include 1/4 inch drive ratchet set.
The fan motor is located behind the front panel.
1. Remove the front panel.
Electrical Shock Hazard
Disconnect electrical
power before beginning
2. Disconnect electrical power.
3. Unplug motor from power harness.
4. Remove bolts (3/8 inch head) holding fan motor
brackets to condenser.
5. Remove screws (1/4” head) holding fan motor to
brackets.
Note: Fan blade is marked “Nut Side” for correct
positioning on motor. Air flow direction is pull thru the
condenser.
Replace condenser
The deck cover cannot be removed without
disconnecting ice making system from the
refrigeration system. The condenser must be replaced
from the front.
Begin by taking the fan motor, blade and brackets off
the condenser.
Then, from the front, remove the screw holding the
condenser to the base.
Next, locate an access hole in the deck above the
back condenser fastener. Remove that screw.
September 2017
Page 22
UF424 / UN324 Technical Manual
Testing Sensors
Photo-Eye Bin Control
Replace Photo-Eye Bin Control
The sensors consist of an emitter and a receiver. The
emitter shines infrared light in a certain pattern at
the receiver. The receiver’s signal is checked by the
controller to confirm proper reception. If confirmed,
the controller starts or continues the ice making
process.
1. Remove top panel.
Remove front panel.
Check controller code display. If the unit is in ice
making mode (status light on) there will normally
either be an F or a b displayed.
If the bin is full, b is displayed.
If the bin is not full and the unit is in ice making mode,
F is displayed.
if the bin is not full and the unit is off, O is displayed.
False bin full: If the bin is not full and b is displayed:
1. Check for loose connection at the harness to the
photo eye sensors.
2. Disconnect photo eye bin control from the quick
connect at the top back of the machine.
3. Lift up and remove both retaining clips holding
sensor holders to evaporator cover.
4. Push sensor holders in towards the center until
free of the evaporator cover.
5. Separate each photo eye sensor from its holder
by pulling them apart.
6. Install new sensor into each holder. Push in until
the rubber from the sensor meets the rubber
sensor holder.
7. Return sensor holders to the chute and insert
retaining clips.
8. Reconnect sensors to harness.
9. Return top panel to its normal position.
2. Check for broken wire at sensor.
3. Check for something blocking the sensors, which
can include scale buildup.
Note: There is no back up for the bin control. If it fails
to shut the machine off, the bin will overfill.
Rotation Sensor
Electrical Shock Hazard
The sensor consists of a pick up sensor and a
magnet. The pick up has a wire that connects to the
controller. The magnet is in the rotating magnet holder
on top of the auger motor. if the rotor is loose, it will
not rotate and the sensor will shut the machine off for
no rotation.
Disconnect electrical
power before beginning
1. Remove front and left side panels.
2. Remove motor cover.
3. Check that rotor has magnet and is secure to
motor shaft.
Note: Special thin open end wrench may be needed
to hold motor shaft, it fits under the magnet rotor.
September 2017
Page 23
UF424 / UN324 Technical Manual
Panel Removal
Top Panel
Requires back access
1. Remove three thumbscrews holding top panel to
back panel.
2. Pull top panel back slightly to release it from the
top of the machine, then lift up and off the unit.
Note: Upper brace may come with top panel, it is not
attached to the unit.
Door
1. Remove top panel.
2. Push door to full open, then lift back end up and
remove two bushings. Retain the bushings.
3. Pull door up thru the slot until the last two
bushings appear. Remove and retain them.
4. Pull door up and out of the machine
Side Panel
1. Remove front, top and back panels.
2. Remove two screws at each side of the top edge
of the unit.
Note: The front screw on the top of each side will not
be tightened fully, its correct position is slightly above
the surface of the top so that the head will fit into the
key hole slots in the top panel.
September 2017
Page 24
UF424 / UN324 Technical Manual
Remove Ice Storage Bin
Replacement of these components requires removal
of the ice storage bin.
•
Water Seal
•
Bottom Bearing
•
Evaporator
•
Gear Reducer
•
Condenser
12.Push chute cover back and remove.
13.Unscrew ice sweep and remove.
Ice Chute
Ice Sweep
1. Disconnect electrical power.
Electrical Shock Hazard
Disconnect electrical
power before beginning
2. Shut water off to machine.
3. Drain the reservoir and evaporator (use drain tube
under control box).
4. Discard any ice.
Remove Ice Sweep and Ice Chute
14.Lift up and remove chute.
5. Pull unit out from under any countertop.
15.Disconnect water inlet from reservoir float valve.
Note: Generous space around the machine will be
needed
16.Disconnect evaporator water inlet from reservoir.
17.Pull water inlet tube back thru hole in bin.
6. Remove front panel.
18.Disconnect bin drain.
7. Remove top panel.
19.Lift bin assembly off chassis.
8. Remove door.
9. Remove both back panels.
10.Remove both side panels.
11.Remove evaporator cover.
Evaporator Cover Removed
September 2017
Page 25
UF424 / UN324 Technical Manual
Remove Gear Reducer
Removal
Note: Below steps assume the bin has been removed.
6. Remove four 1/2” hex head bolts securing
evaporator assembly to gear reducer cover.
Remove or melt out all ice.
1. Disconnect electrical power to unit.
Electrical Shock Hazard
Disconnect electrical
power before beginning
2. Disconnect wires to auger motor.
3. Remove 3 screws holding motor cover to motor.
Remove Evaporator Bolts
7. Remove four 1/2” hex head bolts securing gear
reducer condensate pan to chassis.
Motor
Cover
8. Separate gear reducer from evaporator and lift it
from the machine.
9. Remove three 1/4 hex socket head screws
securing pan to gear reducer.
Install new gear reducer. Be sure vent plug is open
Gear Reducer
4. Remove 4 screws holding rotation sensor holder
to motor.
5. Use a cordless impact driver to remove the screw
holding the magnet rotor. If needed use the
special thin wrench to hold motor shaft.
The gear reducer is a sealed component. No gears or
shaft bearings are available. A gear reducer without
motor is available.
A properly operating gear reducer will operate quietly
and draw a consistent amount of amps. It will not leak
lubricant. Oil discharge is a strong indicator of water
infiltration and is cause for replacement.
High amp draw could be caused by scale build up in
the evaporator. Clean it first, then check amp draw.
Confirm the top and lower bearings are not seized or
rough.
Magnet
Rotor
A motor that rotates but the output shaft does not turn
indicates a stripped gear and is cause for the gear
reducer section to be replaced.
September 2017
Page 26
UF424 / UN324 Technical Manual
Remove Auger
Auger
The auger must be clean and undamaged to work
properly.
A reversed motor code (1) is a strong symptom of a
motor that should be replaced.
Removal
Remove it from the evaporator to confirm.
Suggested tools include a 1/4 inch drive ratchet set.
Note: A wet auger will appear clean - dry it to check
for scale.
1. Disconnect electrical power.
Damaged auger flight edges are not repairable and
the auger must be then be replaced.
3. Remove front panel.
2. Remove top panel.
4. Close float valve or shut water off to unit.
Electrical Shock Hazard
Disconnect electrical
power before beginning
5. Drain reservoir and evaporator using the drain at
the front of the machine.
6. Push back on chute cover, lift up and remove.
7. Remove ice sweep by rotating it counter
clockwise.
8. Lift up and remove chute.
9. Remove the four socket head bolts at the side of
the top of the evaporator.
Auger Motor
The auger motor is a PSC motor with a capacitor. If
the motor will not start, check first for voltage to the
motor.
If there is full voltage to the motor, check the capacitor
and motor windings, replace the motor if the winding
is open. Replace the capacitor if it is damaged, open
or weak.
10.Return ice sweep and attach to auger.
11.Lift up on ice sweep to remove auger. and breaker
together.
Note: The replacement motor is supplied attached
to a gear reducer cover. Remove the motor from the
cover and attach it to the gear reducer.
September 2017
Page 27
UF424 / UN324 Technical Manual
Replace Evaporator
1. Disconnect electrical power
6. Un-braze the evaporator refrigerant inlet and
outlet.
Electrical Shock Hazard
Disconnect electrical
power before beginning
7. Lift the evaporator up and off the bottom bearing
retainer. The stationary half of the water seal will
be in the bottom of the tube. The rotating half is on
the auger.
1. Go thru all steps to remove the auger.
2. Go thru all steps to remove the bin.
3. Recover the refrigerant charge.
4. Remove foam wrap from bottom of evaporator.
8. Confirm auger is un-damaged.
9. Install new water seal.
10.Replace bottom and top bearings.
11.Attach new evaporator to adapter.
12.Replace the dryer and evacuate the system to at
least 300 microns.
5. Remove the four 1/4 inch hex socket head screws
at the bottom of the evaporator.
13.Weigh in the nameplate charge.
September 2017
Page 28
UF424 / UN324 Technical Manual
Replace Auger Motor
Auger Motor
The auger motor may be replaced without removing
the gear reducer. Due to manufacturing and testing
reasons, the replacement auger drive motor is
supplied mounted on a gear reducer cover. It is not
necessary to replace the gear reducer cover.
Electrical Shock Hazard
Disconnect electrical
power before beginning
1. Remove 3 screws holding motor cover to motor.
2. Remove 4 screws holding rotation sensor to
motor.
3. Use a cordless impact driver to remove the
screw holding the magnet rotor. If needed use
the special thin 3/8 open end wrench to hold the
motor shaft.
4. Remove the original drive motor.
5. Separate the replacement drive motor from the
shipping casting.
6. Install the rotor of the replacement motor into the
gear reducer.
7. Attach the winding of the replacement motor to the
gear reducer.
8. Attach the magnet rotor to the new motor shaft.
9. Attach the sensor and its holder to the motor.
10.Attach the motor cover to the motor. Reconnect
wires.
September 2017
Page 29
UF424 / UN324 Technical Manual
Prep to Replace Water Seal or Bearings
It is the manufacturer’s recommendation that the top
bearing, bottom bearing and water seal be replaced at
the same time.
7. Remove four 1/4 inch hex socket head socket
screws.
Extruder / Breaker
Electrical Shock Hazard
Disconnect electrical
power before beginning
1. Remove top panel.
2. Slide chute cover back and remove.
3. Unscrew ice sweep.
8. Return ice sweep to auger.
4. Lift up and pull ice chute off evaporator.
5. Remove four 1/4 inch hex head socket screws.
9. Lift on ice sweep to remove auger.
6. Lift breaker off auger.
Auger
1. Shut water off to machine.
2. Drain reservoir.
10.See Replace Water Seal and Auger Bearings
3. Disconnect electrical power.
4. Remove top panel.
5. Unscrew ice sweep.
6. Lift up and pull ice chute off evaporator.
September 2017
Page 30
UF424 / UN324 Technical Manual
Replace Water Seal and Auger Bearings
Water Seal
Top Bearing:
1. Go thru all steps to remove the auger.
1. Go thru the process of removing the extruder
breaker.
2. Remove the 4 allen head screws at the bottom of
the evaporator.
2. Remove the clip holding the bearing.
3. Lift the evaporator up and off the bottom bearing
retainer.
4. Push the water seal up on one side until it twists,
grab it and pull it out.
5. Remove the rotating half from the bottom of the
auger.
6. Clean the auger shoulder and add a very thin
bead of food grade sealant to the bottom of the
auger.
3. Tap out the old bearing.
4. Use the old bearing as something to tap on and
drive the new bearing into the extruder.
5. Reinstall the clip.
Bottom Bearing:
1. Go thru the process of removing the auger.
2. Remove the 4 allen head screws at the bottom of
the evaporator.
3. Remove the bolts holding the bearing retainer to
the gear reducer.
7. Carefully push the new rotating half of the water
seal up against the sealant as far as possible. It
should seat tightly and straightly against the auger
shoulder. Do not put fingerprints on the sealing
surface.
8. Wet the outside edge of the stationary half of
the water seal and insert it into the bottom of the
evaporator.
4. Separate the gear reducer, evaporator and
bearing retainer.
5. Remove the clip.
6. Tap out the old bearing.
7. Use the old bearing as something to tap on and
drive the new bearing into the extruder.
9. Slip the evaporator onto the bottom bearing
retainer, the bearing retainer will push the water
seal up into the correct position.
Note: The bottom bearing should have been replaced
at this time.
10.Secure the evaporator to the bearing retainer with
the original socket head screws. Be sure they are
tight.
September 2017
Page 31
UF424 / UN324 Technical Manual
Replace Electrical Components
General Access
Power Cord
1. Disconnect electrical power.
1. Disconnect power
2. Remove front, top and right side panels.
3. Pull control box out all the way.
Electrical Shock Hazard
Disconnect electrical
power before beginning
4. Remove power leads from contactor.
5. Pull cord from control box.
6. Loosen strain relief thru access hole in right side
of chassis.
7. Pull cord thru back panel.
2. Remove front panel
3. Remove one screw holding control box to chassis
(above and near the back of the control box).
4. Pull control box out until it stops.
Note: It is critical that only a like OEM power cord be
used as a replacement.
Controller
1. Disconnect electrical power.
2. Remove front panel.
3. Pull control box out.
4. Remove controller cover.
5. Disconnect all wires including the quick connect to
the control box harness.
6. Compress stand offs and lift controller from control
box.
7. Ground yourself to the metal chassis and then
install the replacement controller.
Note: If start capacitor needs testing or replacement,
remove the thumb screw preventing the control box
from being pulled further out.
Potential Relay.
1. Pull control box out.
2. Use long screwdriver from right side to remove
screw holding relay to box.
September 2017
Page 32
UF424 / UN324 Technical Manual
Schematic Diagram
September 2017
Page 33
UF424 / UN324 Technical Manual
Wiring Diagram
September 2017
Page 34
SCOTSMAN ICE SYSTEMS
101 Corporate Woods Parkway
Vernon Hills, IL 60061
800-726-8762
www.scotsman-ice.com
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