Scotsman UF424A-1A, UF424W-1A, UN324A-1A, UN324W-1A, UN324A-6A Technical Manual

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

Specications .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 3

Cabinet Drawing . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 4

Plan and Front Views .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 5

Side and Back Views.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 6

Operational Data .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 7

Placement.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 8

Installation . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 9

Initial Start up .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 10

Maintenance and Cleaning .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 11

Condensers and Air Filter Cleaning.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 13

Operation .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 14

Basic Troubleshooting . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 15

Controller Functions . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 16

Controller Details .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 17

Controller Diagnostics . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 18

Electrical Sequence.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 19

Testing Compressor.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 20

Replace Compressor .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 21

Replace Fan Motor .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 22

Testing Sensors .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 23

Panel Removal .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 24

Remove Ice Storage Bin. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 25

Remove Gear Reducer .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 26

Remove Auger . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 27

Replace Evaporator.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 28

Replace Auger Motor .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 29

Prep to Replace Water Seal or Bearings .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 30

Replace Water Seal and Auger Bearings .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 31

Replace Electrical Components . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 32

Schematic Diagram .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 33

Wiring Diagram .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 34

September 2017

Page 2

UF424 / UN324 Technical Manual

Specications

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

• Minimum: 50o F or 10o C

Water Temperature Limitations

• Maximum: 100o F or 38o C

• Minimum: 40o F or 4.4o C

Water Pressure, Potable

• Maximum: 80 PSI or 5.5 BAR

• Minimum: 20 PSI or 1.3 BAR

Water Pressure, Condenser inlet

• Maximum: 145 PSI or 10 BAR

• Minimum: 20 PSI or 1.3 BAR; can be as low as
5 PSI or 0.3 BAR if clean and supplied with 45o F
water.

F or 38o C

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.

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.

Product Information:

The UF424 produces aked ice and the UN324

produces nugget ice. The ice is stored in an insulated
bin with ice level automatically maintained by the
control system.

A back ow preventer may be required by local

plumbing codes.

Condenser GPM

• 70oF or 21oC water: 0.25 GPM or 0.95 LPM

• 50o F or 10oC water: 0.15 GPM or 0.57 LPM

Voltage 115 volt models

• Maximum 126 VAC

• Minimum 104 VAC

Water Conductivity:

• 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.

Deionized water is not recommended due to its
potential corrosive nature and any damage caused by
DI water will not be covered by warranty.

Has a 5.5 ft. power cord with NEMA 5-15P plug.

Air cooled models ows in the right front and out the
left front and include a cleanable air lter.

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.

Scotsman Ice Systems are designed and
manufactured with the highest regard for safety and

performance. They meet or exceed UL563, veried by

Intertek, ETL.

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

99cm

39.0in

61cm

24.0in

84.7cm

33.4in

AIR
EXHAUST

50.8cm

20.0in

AIR
INLET

September 2017

Page 5

UF424 / UN324 Technical Manual

Side and Back Views

72.8cm

28.7in

5.3cm

2.08in

UTILITY

CLEARANCE

WATER INLET

3/8 FLARE

CONDENSOR
WATER DRAIN
CONNECTION
1/2-14 NPT

POWER
CORD

15.1cm

6.0in

51.4cm

20.3in

UNIT DRAIN
3/4" FPT

CONDENSER WATER
INLET 3/8-18NPT

11.9cm

4.7in

13.6cm

5.4in

16.8cm

6.6in

WATER REGULATOR

ADJUSTMENT ACCESS

7.8cm

3.1in

17.5cm

6.9in

24.5cm

9.7in

September 2017

Page 6

UF424 / UN324 Technical Manual

Operational Data

High Pressure

Electrical

Model

(Volts/Hz/Phase)

UF424A-1A / UN324A-1A 115/60/1 Air 260 190 12 15

UF424W-1A / UN324W-1A 115/60/1 Water 260 190 12 15

UF424A-6A / UN324A-6A 230/50/1 Air 260 190

Model Typical Watts Typical Amps Auger Motor Amps Compressor Amps

UF424A-1A / UN324A-1A

UF424W-1A / UN324W-1A

UF424A-6A / UN324A-6A

560 - 690 6.3 - 7 1.1 - 1.4 5 - 5.8

540 - 575 6.1 - 6.7 1.1 - 1.4 5 - 5.8

Condenser

Switch (PSIG)

Cut Out Cut In

Refrigerant

Charge

(R-134a)

Ounces

Maximum Fuse Size

or Breaker (Amps)

Model Condenser 70/50 Suction

Pressure
(PSIG)

UF424A-1A / UN324A-1A

UF424W-1A / UN324W-1A

Note: 70/50 and 90/70 refer to the air and water temperatures (in degrees F) the machine was tested in. All

eld conditions are unique, but at temperatures near those listed a eld machine will have similar results.

Air 6 - 8 8 - 9 130-135 180 - 185

Water 6 - 8 6 - 8 135 135

90/70 Suction
Pressure
(PSIG)

70/50
Discharge
Pressure
(PSIG)

90/70
Discharge
Pressure
(PSIG)

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 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.

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 specically

approved by Scotsman.

Scotsman reserves the right to make design changes
and/or improvements at any time.

Specications and design are subject to change

without notice.

Airow on air cooled models:

Intake from the right grill

Exhaust from the left grill

Do not install where this air ow is blocked.

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.

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.

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 di󰀩cult it

will be to remove it.

Airow

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 ltered.
Install a lter system that lters out suspended solids.
It may be necessary to add a coarse pre-lter ahead
of the ne lter.

Inspect the place where the ice machine is to be
installed. Check for:

• 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 o󰀨 valve

accessible when the unit is installed.

For the Plumber

1. Connect cold potable water to the 3/8’’ male

are behind the lower back panel. A water
lter 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 ow 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 tting. Drain

tubes for a water cooled machine should be

run separately. The bin drain tting 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 tting 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 nal 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 conrmed within the
specications 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 o󰀨 valve installed near the ice

maker

Start up:

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 o󰀨 will be

several inches below the door. When ice level drops
from use or meltage, the ice machine will resume
making ice.

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, lls and then shuts o󰀨. Check

for leaks. Repair any leaks before going further.

4. Switch electrical supply on. Lights on controller

will ash and then the power light will remain on.

The code display will show O.

5. Push and release the On/O󰀨 button. The machine
will start the ice making process. The code display
will show F. Air cooled models will discharge
warm air
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.

6. Push the on/o󰀨 button to switch the machine o󰀨.
Scoop out any ice in the bin.

out the left side of the front panel.

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 e󰀨ort was made during

its design to minimize the sound level but some is
unavoidable.

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 lters

Ice making System:

Remove Scale

1. Remove front panel.

2. Turn the machine o󰀨 by pressing the on / o󰀨
button.

Reservoir

5. Remove the top cover from the reservoir.

6. Shut water supply o󰀨 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, ush 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 ll

reservoir with cleaning solution).

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 o󰀨.

13. Drain the solution from the reservoir by removing
the plug. Once drained, replace the plug.

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 /O󰀨
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

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.

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.

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 lter located on the lower front grill will capture

airborne dust during operation. As the dirt builds up, it

begins to restrict air ow and causes the refrigeration
system to work less e󰀩ciently. Clean the air lter

regularly.

1. Remove the lter by sliding it to the right until it
is clear of the ice machine.

Note: It is a snap t and the snaps may be very tight.

Pull hard with two thumbs.

2. Remove dust and dirt by washing the lter in a
utility sink.

3. Reinstall lter in the ice machine.

Condenser

The condenser ns require semi annual cleaning. Use
caution to prevent damage to the condenser ns.

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 ow to

maintain the discharge pressure set point.

That pressure is factory set to 135 PSIG. If needed, it

may be eld 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 o󰀨 mode of the machine. A push of the on o󰀨 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 aked or
nugget ice, depending upon the design of the breaker. As ice exits the breaker or extruder, more water ows

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 aker 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 oor

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 rst shut o󰀨 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 o󰀨 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 o󰀨. 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 o󰀨 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 Possible Cause Probable Correction

No ice in bin Unit in o󰀨 mode or o󰀨 on

error code.

False bin full

No power to unit Check for the power light on the controller. If not

Auger motor not operating Open windings. Check motor windings and replace

Compressor not operating Contactor coil is open, check and replace if needed.

Compressor operating,
auger turning, no ice is
made

Excessive noise Tubing contact Check for tubes rattling and panels not tight

Fan blade out of balance Replace fan blade
Compressor noisy Replace compressor

Moaning noise when
making ice

Slow or Low production Air lter is dirty Clean air lter

Unit cycles o󰀨 and

restarts

Water seal being
compressed

Condenser is dirty Check and clean condenser
Room and/or Water

Temperature too high

Restricted air ow to unit Check and remove air ow restrictions

Loose electrical connection Check power cord and outlet. Outlet may be worn,

Remove front panel and check controller code
display. Push ON/OFF button to reset. See pages
16 and 17 for further details.

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.

illuminated restore power.

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.

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.

Gear reducer bearing failure, replace gear reducer

Maximum production will be achieved at 70°F / 21°C
air and 50° / 10°C water

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.

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/O󰀨 - to switch the machine on or o󰀨. Holding it

in to shut o󰀨 will stop ice making immediately.

• Clean - to engage the clean mode

Indicators - there are ve 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

There is also a code display, the codes are:
O - - - for o󰀨
F - - - for ice making
b - - - for bin full
E - - - for controller error
C - - - for clean mode
d - - - for test mode
1 - - - for auger rotation direction wrong
2 - - - for auger speed too slow
3 - - - for no water sensed
4 - - - 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.

To reset the control when it has been manually locked

out, Push and release the On/O󰀨 button to shut it O󰀨

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 o󰀨.

• Compressor - glows when the compressor is on

September 2017

Page 16

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 o󰀨 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 o󰀨 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/o󰀨 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 o󰀨 for at least 2 minutes.

• There is a Test Mode. The Test Mode operates each load in sequence to conrm 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) On O󰀨
0 Compressor Auger Gear Motor
10 Compressor and Auger Gear Motor
20 Auger Gear Motor Compressor
20 None Auger Gear Motor, Compressor
40 None 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 rmware 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 ashes 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/

O󰀨 button. The controller will revert to the original rmware.

September 2017

Page 17

UF424 / UN324 Technical Manual

Controller Diagnostics

Code or Light Action Probable Cause Suggested Action

O
F
b
E
C
d

1

2

3

4

Status light is on Unit is in ice making mode Normal, may not be making ice if

Time to Clean light is on Unit has not been cleaned for at

Unit manually switched o󰀨 If desired, switch unit on.

Freeze mode None, unit is making ice.

Bin sensors sense bin full Check if bin is full.

Corrupted memory Replace controller

Clean mode Continue clean mode

Test mode None, allow unit to nish test

mode.

Auger motor rotated auger
backwards.

Auger motor stalled or operating
slowly

No water in reservoir Restore water. If there is water,

High pressure cut out open Check fan motor on air cooled or

least 6 months

Replace auger motor. Check water
seal area for leaks, replace seal if
leaking.

Clean ice making system and retry.

If unit shuts o󰀨 again right after a

reset, magnet rotor on motor shaft
may be loose.

is it too pure? Are sensor wires
connected?

water supply on water cooled.

bin is full
Clean unit

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 eld. Replace controller.

September 2017

Page 18

UF424 / UN324 Technical Manual

Electrical Sequence

When electrical power is connected, and the prior

mode was O󰀨, the controller veries the voltage and
performs a self check. If the self check conrms 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.

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.

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.

Timings

• 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 o󰀨: 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.

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/O󰀨 button, unit will display O. To restart: push and
release the On/O󰀨 button again.

Manually shut down either by pushing and releasing

the On/O󰀨 button (compressor shuts o󰀨, auger motor
continues for a minute) or by holding in the On/O󰀨

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.

Items that can a󰀨ect that are:

• Irregular water ow

• Erratic thermostatic expansion valve

• Changes in room air temperature

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

Capacitor Testing

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.

If the capacitor looks ok, check it with a multimeter.

1. Discharge the capacitor.

2. Set a digital meter to a high resistance scale of at
least 4k.

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.

The compressor gets its power from the contactor,
which is operated by the controller. It must be working

or the compressor will be o󰀨.

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.

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 ow 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 o󰀨

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

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 conrm proper reception. If conrmed,

the controller starts or continues the ice making
process.

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 o󰀨, 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. Check for broken wire at sensor.

Replace Photo-Eye Bin Control

1. Remove top panel.

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.

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 o󰀨, the bin will overll.

Rotation Sensor

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 o󰀨 for

no rotation.

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 ts under the magnet rotor.

Electrical Shock Hazard

Disconnect electrical
power before beginning

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 o󰀨 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 t 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

1. Disconnect electrical power.

Electrical Shock Hazard

Disconnect electrical
power before beginning

2. Shut water o󰀨 to machine.

3. Drain the reservoir and evaporator (use drain tube
under control box).

4. Discard any ice.

5. Pull unit out from under any countertop.

Note: Generous space around the machine will be
needed

12. Push chute cover back and remove.

13. Unscrew ice sweep and remove.

Ice Chute

Ice Sweep

Remove Ice Sweep and Ice Chute

14. Lift up and remove chute.

15. Disconnect water inlet from reservoir oat valve.

16. Disconnect evaporator water inlet from reservoir.

17. Pull water inlet tube back thru hole in bin.

6. Remove front panel.

7. Remove top panel.

8. Remove door.

9. Remove both back panels.

10. Remove both side panels.

11. Remove evaporator cover.

Evaporator Cover Removed

18. Disconnect bin drain.

19. Lift bin assembly o󰀨 chassis.

September 2017

Page 25

UF424 / UN324 Technical Manual

Remove Gear Reducer

Removal

Note: Below steps assume the bin has been removed.

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.

Motor
Cover

6. Remove four 1/2” hex head bolts securing
evaporator assembly to gear reducer cover.

Remove Evaporator Bolts

7. Remove four 1/2” hex head bolts securing gear
reducer condensate pan to chassis.

8. Separate gear reducer from evaporator and lift it
from the machine.

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.

Magnet
Rotor

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

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

inltration and is cause for replacement.

High amp draw could be caused by scale build up in

the evaporator. Clean it rst, then check amp draw.
Conrm the top and lower bearings are not seized or

rough.

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.

Remove it from the evaporator to conrm.

Note: A wet auger will appear clean - dry it to check
for scale.

Damaged auger ight edges are not repairable and

the auger must be then be replaced.

A reversed motor code (1) is a strong symptom of a
motor that should be replaced.

Removal

Suggested tools include a 1/4 inch drive ratchet set.

1. Disconnect electrical power.

2. Remove top panel.

3. Remove front panel.

4. Close oat valve or shut water o󰀨 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.

Auger Motor

The auger motor is a PSC motor with a capacitor. If

the motor will not start, check rst 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.

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.

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

Electrical Shock Hazard

Disconnect electrical
power before beginning

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.

6. Un-braze the evaporator refrigerant inlet and
outlet.

7. Lift the evaporator up and o󰀨 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.

5. Remove the four 1/4 inch hex socket head screws
at the bottom of the evaporator.

8. Conrm 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.

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.

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.

4. Lift up and pull ice chute o󰀨 evaporator.

5. Remove four 1/4 inch hex head socket screws.

6. Lift breaker o󰀨 auger.

7. Remove four 1/4 inch hex socket head socket
screws.

8. Return ice sweep to auger.

9. Lift on ice sweep to remove auger.

Auger

1. Shut water o󰀨 to machine.

2. Drain reservoir.

3. Disconnect electrical power.

4. Remove top panel.

5. Unscrew ice sweep.

6. Lift up and pull ice chute o󰀨 evaporator.

10. See Replace Water Seal and Auger Bearings

September 2017

Page 30

UF424 / UN324 Technical Manual

Replace Water Seal and Auger Bearings

Water Seal

1. Go thru all steps to remove the auger.

2. Remove the 4 allen head screws at the bottom of
the evaporator.

3. Lift the evaporator up and o󰀨 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.

Top Bearing:

1. Go thru the process of removing the extruder
breaker.

2. Remove the clip holding the bearing.

3. Tap out the old bearing.

4. Use the old bearing as something to tap on and
drive the new bearing into the extruder.

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 ngerprints 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.

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.

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.

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.

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

1. Disconnect electrical power.

Electrical Shock Hazard

Disconnect electrical
power before beginning

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.

Power Cord

1. Disconnect power

2. Remove front, top and right side panels.

3. Pull control box out all the way.

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.

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.

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.

6. Compress stand o󰀨s and lift controller from control
box.

7. Ground yourself to the metal chassis and then
install the replacement controller.

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