This manual is updated as new information and models
are released. Visit our website for the latest manual.
America’s #1 Selling Ice Machine
Manitowoc Ice P/N 040004390 11/14
www.manitowocice.com
Page 2
Page 3
Safety Notices
!
Warning
!
Caution
When using or servicing these Ice Machines, be sure
to pay close attention to the safety notices in this
handbook. Disregarding the notices may lead to
serious injury and/or damage to the ice machine.
Throughout this handbook, you will see the following
types of safety notices:
Text in a Warning box alerts you to a potential
personal injury situation. Be sure to read the
Warning statement before proceeding, and work
carefully.
Text in a Caution box alerts you to a situation in
which you could damage the ice machine. Be sure
to read the Caution statement before proceeding,
and work carefully.
Page 4
Procedural Notices
Important
When using or servicing these Ice Machines, be sure
to read the procedural notices in this handbook. These
notices supply helpful information that may assist you
as you work.
Throughout this handbook, you will see the following
types of procedural notices:
Text in an Important box provides you with
information that may help you perform a procedure
more efficiently. Disregarding this information will not
cause damage or injury, but may slow you down as
you work.
NOTE:
simple, but useful extra information about the
procedure you are performing.
Text set off as a Note provides you with
Page 5
Read These Before Proceeding:
!
Caution
Important
!
Warning
!
Warning
Proper installation, care and maintenance are
essential for maximum ice production and trouble
free operation of your Manitowoc Ice Machine. If you
encounter problems not covered by this manual, do
not proceed, contact Manitowoc Ice, Inc. We will be
happy to provide assistance.
Routine adjustments and maintenance procedures
outlined in this manual are not covered by the
warranty.
We reserve the right to make product improvements at
any time. Specifications and design are subject to
change without notice.
PERSONAL INJURY POTENTIAL
Do not operate equipment that has been misused,
abused, neglected, damaged, or altered/modified
from that of original manufactured specifications.
POTENTIAL PERSONAL INJURY SITUATION
This ice machine contains refrigerant charge.
Installation and Servicing must be performed by a
properly trained refrigeration technician aware of the
The location selected for the ice machine must meet
the following criteria. If any of these criteria are not
met, select another location.
• The location must be indoors.
• The location must be free of airborne and other
contaminants.
• The air temperature must be at least 10ºC but must
not exceed 43.4ºC.
• The location must not be near heat-generating
equipment or in direct sunlight.
• The location must be capable of supporting the
weight of the ice machine and a full bin of ice.
• The location must allow enough clearance for water,
drain, and electrical connections in the rear of the
ice machine.
• The location must not obstruct airflow through or
around the ice machine (condenser airflow is in and
out the front). Refer to the chart below f or clearance
requirements.
Self-Contained
Air-Cooled
Top/Sides203 mm (8")*127 mm (5")*
Back127 mm (5")*127 mm (5")*
*NOTE:
There is no minimum clearance requirement for the
top or left and right sides of the ice machine. The listed
values are recommended for efficient operation and
servicing only.
The ice machine may be built into a cabinet.
Self-Contained
Water-Cooled
3
Page 14
WATER SERVICE/DRAINS
!
Caution
Water Supply
Local water conditions may require treatment of the
water to inhibit scale formation, filter sediment, and
remove chlorine odor and taste.
Water Inlet Lines
• Do not connect the ice machine to a hot water
supply. Be sure all hot water restrictors installed for
other equipment are working. (Check valves on sink
faucets, dishwashers, etc.)
• If water pressure exceeds the maximum
recommended pressure, 5 bar (500 kPA), install a
water pressure regulator.
• Install a water shut-off valve.
Drain Connections
• Drain lines must have a 2.5 cm per meter drop, and
must not create traps.
• The floor drain must be large enough to
accommodate drainage from all drains.
The ice machine must be protected if it will be
subjected to temperatures below 0°C. Failure
caused by exposure to freezing temperatures is not
covered by the warranty.
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ELECTRICAL REQUIREMENTS
Voltage
The maximum allowable voltage variation is ±6% of
the rated voltage on the ice machine model/serial
number plate at start-up (when the electrical load is
highest).
All ice machines are factory pre-wired with a power
cord only, no plug is supplied.
Fuse/Circuit Breaker
A separate fuse/circuit breaker must be provided for
each ice machine. An electrical disconnect switch
must be provided if the ice machine is hard wired
(wired without a plug).
Total Circuit Ampacity
The total circuit ampacity is used to help select the
wire size of the electrical supply.
The wire size (or gauge) is also dependent upon
location, materials used, length of run, etc., so a
qualified electrician must make the determination.
5
Page 16
6
ELECTRICAL SPECIFICATIONS
Ice Machine
UG018230/1/50102.0N/AN/A
UG020
UG030
UG040
Voltage/Phase/
Air-CooledWater-Cooled
m Fuse/
Cyc
le
230/1/50102.3N/AN/A
230/1/60102.3N/AN/A
230/1/50152.8152.5
230/1/60152.8N/AN/A
115/1/60155.5N/AN/A
230/1/50153.0N/AN/A
230/1/60153.0 N/AN/A
Maximu
Circuit Breaker
Total Am ps
Maximum
Fuse/Circuit
Breaker
Tot a l Amps
Page 17
230/1/50154.0152.8
UG050
UG065
UG080
7
230/1/60154.0N/AN/A
115/1/60156.8N/AN/A
230/1/50154.5N/AN/A
230/1/60154.5N/AN/A
230/1/50155.5N/AN/A
230/1/60155.5N/AN/A
Page 18
ICE MACHINE HEAT OF REJECTION
Series Ice
Machine
Air ConditioningPeak
Heat of Rejection
UG181,1502,300
UG201,4002,600
UG301,9003,300
UG402,1004,100
UG502,6005,000
UG652,9005,000
UG804,3007,400
BTU/Hour
Because the heat of reje ction varies during the ice
making cycle, the figure sho wn is an average.
8
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Component Identification
Water
Curtains
Water
Trough
Control
board
On/Off/Wash-Fill
Tog g l e S w it c h
Air Cooled
Condenser
9
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Evaporator
Spra y
Nozzles
Toggle Switch
Spra y B ar
Ice Chute
10
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COMPONENT REMOVAL
Remove 2 Screws and
Slide Cover Back
T op Cove r
For easiest access to the evaporator compartment, the
top cover can be removed.
1. Remove two screws on the rear of the ice
machine.
2. Slide top cover back to disengage the three pins
from the front panel
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Bin Door
Align Door Pins With
Track Slots, Then Lift
Door Out Of Track
Allows access to the storage bin.
1. Remove top cover.
2. Slide door up until rear pins align with slot in door
tracks.
3. Lift rear door pins out and slide door up until front
door pins align with slot.
4. Lift door out of door track
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Water Curtain
Water Curtain
The water curtain is designed to keep the spraying
water from escaping the evaporator compartment.
Removal of the bin door is not required, but enhances
access.
1. Grasp the ice curtain and lift up.
2. To re-install into ice machine, pivot the water
curtain and pull down into position. Make sure
tabs are secure in grooves.
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Ice Chute
Ice Chute
The ice chute is positioned over the spray nozzles and
allows the ice to easily fall into the bin. It must be firmly
positioned over the Spray Bar Assembly, with the front
edge inside the water trough or the spray nozzles will
not be aligned with the spray holes, and spray water
will fall into bin.
1. Grab protruding spray holes on one end and lift
up.
2. Pivot ice chute and remove.
3. To re-install ice chute, grasp protruding spray
holes and position over Spray Bar Assembly.
Make sure rear supports are over Spray Bar
Assembly, and front edge is inside of water trough
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SPRAY BAR
The spray bar supplies water to the individual icemaking cups. Water from the Water Pump sprays
through the nozzles, located on the upper portion of
the tubes.
1. Grasp one end of the spray bar, lift up and remove
from seat formed in water trough.
2. Remove both plastic clips on water inlet tubing by
grasping both ears on clip and separating.
3. Apply food grade lubricate to ease re-assembly of
spray bar components when necessary.
4. To re-install spray bar, position water inlet tubing
on inlet ports, and squeeze clips until tight.
5. Reposition assembly on water trough seat.
NOTE:
Nozzles and inserts can be removed for
cleaning by unscrewing nozzles. Inserts are located
inside the spray bar ports. The spray bar also
disassembles for easy cleaning
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Sump Drain Overflow Tube
Overflow Tube
The sump drain overflow tube is located in the
evaporator water sump.
1. Remove shutters and ice chute.
2. Lift spray bar or disconnect and remove for
easiest access.
3. Pull up on over flow tube to remove.
To replace plug, insert in hole, and push with force to
make a tight seal
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Maintenance
!
Caution
!
Warning
INTERIOR CLEANING AND SANITIZING
GENERAL
Clean and sanitize the ice machine every six months
for efficient operation. If the ice machine requires more
frequent cleaning and sanitizing, consult a qualified
service company to test the water quality and
recommend appropriate water treatment.
An extremely dirty ice machine must be taken apart for
cleaning and sanitizing.
Use only approved Ice Machine Cleaner and
Sanitizer. Read and understand all labels printed on
bottles before use. Do not mix Ice Machine Cleaner
and Sanitizer solutions together
Wear rubber gloves and safety goggles (and/or face
shield) when handling Ice Machine Cleaner or
Sanitizer.
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CLEANING & SANITIZING PROCEDURE
!
Caution
Ice machine cleaner is used to remove lime scale or
other mineral deposits. Sanitizer is used to remove
algae or slime.
Mix 4 liters of water with 500 ml of cleaner in a plastic
or stainless container.
CleanerWater
500 ml (16 oz) 4 l (1 gal)
Step 1 Set the toggle switch to the OFF position at the
end of a Harvest Cycle, after ice releases from the
evaporator. Or, set the switch to the OFF position and
allow the ice to melt off the evaporator.
Never use anything to force ice from the
evaporator. Damage may result.
Step 2 Remove all ice from the bin.
Step 3 Remove all parts as described in Section 3,
Component Identification & Removal.
Step 4 Take all components to sink and with 2 liters
Cleaner/Water mixture clean all components with a
soft nylon brush. Disassemble spray bar, remove
nozzles and inserts and soak for 5 minutes. For
heavily scaled parts, soak in solution for 15–20
minutes. Rinse all components with clean water.
Step 5 While components are soaking; use nylon
brush to scrub inside of ice bin. Scrub inside of door,
door track, bin, sump trough, and evaporator
moldings. With clean water, rinse all of these areas
thoroughly.
Step 6 Replace sump overflow tube and pour
remaining 2 liters of mixture into the water sump.
Replace all parts.
Step 7 To start a cleaning cycle, set the toggle switch
to the WASH position.
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Step 8 After 13.5 minutes, set the toggle switch to the
OFF position. Remove water curtain, ice chute and
over flow tube from the water sump. Allow all water to
drain from the sump. Replace drain plug . Set toggle
switch to WASH and circulate for 12minutes.
Step 9 Wait until the cleaning cycle(12minutes) is
complete then place the toggle switch in the OFF
position.Remove water curtain, ice chute, water sump
over flow tube. Drain water from sump and replace
tube.
Step 10 Mix 60 ml of sanitizer with 12 l of water in a
plastic or stainless steel container.
SanitizerWater
60 ml (2 oz)12 l (3 gal)
Step 11 Remove Water Curtain and Ice Chute as
described in Section 3, Component Identification &
Removal.
Step 12 Take all components to sink and with 10 liters
Sanitizer/Water mixture sanitize all components with a
soft nylon brush or cloth. Do not rinse components.
Step 13 Use brush or cloth to sanitize the inside of ice
bin. Scrub inside of door, door track, bin, water sump,
water distribution assembly and evaporator moldings.
Do not rinse.
Step 14 Replace sump drain over flow tube, and
transfer remaining 2 liters of solution to the sump
trough. Replace all components.
Step 15 To start a sanitizing cycle, set the toggle
switch to the WASH position.
Step 16 After 13.5 minutes, set the toggle switch to
the OFF position. Remove water curtain and ice chute
Remove over flow tube from water sump and allow all
water to drain from sump. Replace drain plug. Set
toggle switch to WASH and circulate for 12
minutes.
Step 17 Wait until the cleaning cycle (12minutes) is
complete then place the toggle switch in the OFF
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position. Remove water curtain, ice chute, water sump
over flow tube. Drain water from sump and replace tub
Step 18 Replace all parts.
Step 19 Place toggle switch to ON position,ice
machine will go into ice making cycle.
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EXTERIOR CLEANING
!
Caution
Clean the area around the ice machine as often as
necessary to maintain cleanliness and efficient
operation.
Sponge any dust and dirt off the outside of the ice
machine with mild soap and water. Wipe dry with a
clean, soft cloth.
A commercial grade stainless steel cleaner and polish
may be used.
REMOVAL FROM SERVICE/WINTERIZATION
GENERAL
Special precautions must be taken if the ice machine is
to be removed from service for an extended period of
time or exposed to ambient temperatures of 0°C
(32°F) or below.
If water is allowed to remain in the ice machine in
freezing temperatures, severe damage to some
components could result. Damage of this nature is
not covered by the warranty.
Follow the applicable procedure below.
AIR-COOLED ICE MACHINES
1. Disconnect the electric power at the circuit
breaker or the electric service switch.
2. Turn off the water supply.
3. Drain the water from the water sump and water
pump by disconnecting the water pump tubing.
4. Disconnect and drain the incoming ice-making
water line and disconnect the tubing from the
water inlet valve outlet and allow water to drain.
5. Blow compressed air in the drain opening and
water valve outlet hose, then reattach.
6. Make sure water is not trapped in any of the water
or drain lines.
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WATER-COOLED ICE MACHINES
1. Perform steps 1-6 under “Air-Cooled Ice
Machines.”
2. Disconnect the incoming water and drain lines
from the water-cooled condenser.
3. Insert a large screwdriver between the bottom
spring coils of the water regulating valve. Pry
upward to open the valve.
4. Hold the valve open and blow compressed air
through the condenser until water no longer exits.
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Operation
Sequence Of Operation
I
NITIAL START-UP
1. Water Inlet and Pressure Equalization
Turn the toggle switch to”ON” positon,the water fill
valve and harvest valve are energized, 300 seconds
, the water fill valve is de-energized. 20seconds
later
after the harvest valve solenoid is energized, the
compressor is energized. 300seconds after the
compressor is energized, the harvest valve solenoid is
de-energized, the water pumpand the fan motor are
energized,machine goes into freeze cycle.
2. Freeze Cycle
The pump sprays water into the inverted cups. The
water freezes layer by layer, until an ice cube forms in
each cup.
When the”water temperature”is equal to or less than 2
? for more than 5 seconds, control will read the” liquid
line temperature” and dip switch setting , get the”
freeze postpone time” and “fan shut off time”.Board
will shut the Fan before the end of the freeze cycle to
assist harvest. When the ” freeze postpone time” has
elapsed, the harvest cycle is initiated.
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3. Harvest Cycle
The compressor continues to operate and the water
pump is de-energized. The hot gas valve energizes,
allowing hot gas to enter and warm the evaporator.
The water valve is also energized, aiding with harvest,
as well as filling up the sump with fresh water for a
new freeze cycle.
at the point of 2 minutes to freeze end , board will read
the ” liquid line temperature”again and calculate the
“harvest time”
The ice falls from the cups and is directed into the bin
by the ice chute. The harvest cycle continues until the
harvest time has elapsed,then machine goes into a
new freeze cycle
4.Automatic Shut-Off
When the storage bin is full, the ice will come in
contact with the bin thermostat which is located inside
the bin. The machine will stop after approximately
45seconds of continuous ice contact with the bin
thermostat probe.
The ice machine remains off until a 3 minutes delay
has elapsed and enough ice has been removed from
the storage bin to allow the ice to fall clear of the bin
thermostat probe. As the ice clears the probe, the bin
thermostat warms up and the machine starts another
freeze cycle.
NOTE:
Be Careful not to turn the ice machine to WASH by
mistake. If so then you will need to follow the
WASH procedure until finished. Or, to bypass the
WASH lock-in, press the Test Button
3 times in 10 seconds and then set the
board)
toggle switch to the OFF position.
(in control
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I
ICE CUBE THICKNESS CHECK
The ice cube thickness is factory-set to maintain the
ice cube thickness at the proper size and weight.
1. Allow the ice machine to operate for three
complete cycles. The cubes should have a small
dimple in the center.
2. Cycle times vary, according to surrounding air and
water inlet temperatures.
3. If cubes are not full (large dimple), raise the “dip
switch” level to increase cube size. Allow ice
machine to complete three cycles, then check
cube.
4. If cubes are too full, ( no dimple), lower the “dip
switch” level to decrease cube size.Allow ice
machine to operate three complete cycles.
5. The “dip switch” can be adjusted to five levels: -2/
+1/+
-1/0/
2, and ensure that only one level switch
is pressed
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.
dip switch
Decrease
Cube Size
Factory
Default
Setting
Increase
Cube Size
test button
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CUBE SHAPE
The standard cube has an average weight of 19
Notice the normal dimple in the center of the cube.
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Troubleshooting
All Models
ICE MACHINE WILL NOT RUN
Nothing on the ice machine will operate (compressor,
water pump, condenser fan motor). If any component
runs this procedure can be skipped, move on to the
next diagnostics (water pump won’t run, compressor
won’t run, etc).
1. Place the toggle switch in the clean position. If the
water pump runs begin with toggle switch
diagnostics. If water pump does not run place
toggle switch in ice position.
2. Verify correct voltage is present and matches
nameplate voltage.
3. High pressure switch must be closed on water
cooled ice machines
4. Bin thermostat must be closed before any
components can be energized.
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COMPRESSOR WON’T RUN
If the water pump is running and the compressor is
not, it may be tripping on overload or tripping the
breaker/fuse. Check for grounded winding if breaker
keeps tripping.
1. Compressor Relay LED lit?
2. Start capacitor and relay function?
3. Compressor windings closed?
4. Refer to compressor diagnostics.
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COMPRESSOR ELECTRICAL DIAGNOSTICS
The compressor does not start or will trip repeatedly
on overload.
Check Resistance (OHM) Values
NOTE:
Compressor windings can have very low ohm
values. Use a properly calibrated meter.
Perform the resistance test after the compressor
cools. The compressor dome should be cool enough
to touch (below 49°C) to assure that the overload is
closed and the resistance readings will be accurate.
Single Phase Compressors
1. Disconnect power from the condensing unit and
remove the wires from the compressor terminals.
2. The resistance values between C and S and
between C and R, when added together should
equal the resistance value between S and R.
3. If the overload is open, there will be a resistance
reading between S and R, and open readings
between C and S and between C and R. Allow the
compressor to cool, then check the readings again.
Check Motor Windings to Ground
Check continuity between all three terminals and the
compressor shell or copper refrigeration line. Scrape
metal surface to get good contact. If continuity is
present, the compressor windings are grounded and
the compressor should be replaced.
To determine if the Compressor is seized check the
amp draw while the compressor is trying to start.
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Compressor Drawing High Amps
The continuous amperage draw on start-up should not
be near the maximum fuse size indicated on the serial
tag.
The wiring must be correctly sized to minimize voltage
drop at compressor start-up. The voltage when the
compressor is trying to start must be within (6% of the
nameplate voltage).
Compressor Drawing Locked Rotor
The three likely causes of this are:
• Low voltage supply (check voltage while
compressor is trying to start)
• Defective starting component
• Mechanically seized compressor
To determine which you have:
• Install high and low side gauges.
• Try to start the compressor.
• Watch the pressures closely.
If the pressures do not move, the compressor is
seized. Replace the compressor.
If the pressures move, the compressor is turning
slowly and is not seized. Check the capacitors and
relay.
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DIAGNOSING START COMPONENTS
If the compressor attempts to start, or hums and trips
the overload protector, check the start components
before replacing the compressor.
Capacitor
Visual evidence of capacitor failure can include a
bulged terminal end or a ruptured membrane. Do not
assume a capacitor is good if no visual evidence is
present. A good test is to install a known good
substitute capacitor. Use a capacitor tester when
checking a suspect capacitor. Clip the bleed resistor
off the capacitor terminals before testing.
Current Relay
The relay has a set of contacts that energize and deenergize the compressor start winding. The contacts
on the relay are normally open (start winding deenergized). When power is applied the run winding will
be at LRA. The relay coil will become an
electromagnet and close the contacts (start winding
energized). As the compressor motor RPM increases,
the run winding current draw and relay coil magnetism
decrease allowing the contacts to open. Replace a
suspect relay with a known good relay, or use a
momentary switch and start capacitor to mimic relay
operation.
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WATER PUMP WON’T RUN
1. Water pump winding closed?
• Yes-rebulid or replace water pump.
• No-Water Pump Relay LED on control board lit?
∗ Yes:repair wiring
∗ No: rebulid or replace control board
HOT GAS VALVE WON’T ENERGIZE
1. Line voltage at hot gas valve?
• Yes - Replace hot gas valve coil.
• No - Hot gas valve Relay LED on control board lit?
∗ Yes:repair wiring
No:rebulid or replace control board
WATER INLET VALVE WON’T ENERGIZE
1. Line voltage at water inlet valve?
• Yes - Replace water inlet valve coil.
• No - water inlet valve Relay LED on control board
lit?
∗ Yes:repair wiring
No:rebulid or replace control board
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ICE MACHINE PREMATURELY HARVESTS
1. Line voltage at hot gas valve?
> No - Replace hot gas valve.
2. had set the "dip switch"?
>Yes - Refer to"ice cube thickness check"
djusting increase cube size(increase Increased
a
ice freeze time)
Refer to" thermistor diagnostics.” test the Water
Thermistor and the Liquid Line Thermistor .
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CE MACHINE WILL NOT HARVEST
1. Liquid Line Thermistor temperature below
setpoint?
2. Liquid Line Thermistor sensor installation
correctly?
3. Refer to" thermistor diagnostics.” test the Liquid
Line Thermistor.
Line voltage at hot gas valve and water inlet Solenoid?
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Page 47
EVAPORATOR THERMOSTAT
Function
Thermistor resistance values change with
temperature.The value supplied to the control board is
used toInitiates and terminates freeze cycle?harvest
cycle and automatic shutdown?
Three thermistors are located on the ice machine.
are labeled T1, T2, T3?
They
T1- Water thermistor located at the water trough.
T2- Liquid line thermistor sensor located at outlet of
the condenser.
T3-Bin full thermistor sensor located at top of
the bin.
SPECIFICATIONS
TI &T3
Temperatur
e of
Thermistor
°C
-50344.6264.771
-49320.5274.567
-48298.2284.375
-47277.6294.190
-46258.7304.016
-45241.1313.849
-44224.8323.690
-43209.8333.538
-42195.9343.394
-41183.0353.256
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
Resistance
K Ohms (x
1000)
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Page 48
Temperatur
e of
Thermistor
°C
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
-40171.0363.124
-39159.9372.999
-38149.5382.879
-37140.0392.764
-36131.1402.656
-35122.8412.551
-34115.1422.452
-33108.0432.356
-32101.2442.266
-3195.03452.179
-3089.24462.095
-2983.83472.016
-2878.79481.940
-2774.09491.867
-2669.70501.797
-2565.58511.731
-2461.75521.667
-2358.16531.606
-2254.81541.547
-2151.66551.491
-2048.72561.437
-1945.97571.385
-1843.39581.336
-1740.96591.289
-1638.69601.243
-1536.56611.200
-1434.56621.158
-1332.68631.117
-1230.92641.079
-1129.25651.041
-1027.70661.006
Resistance
K Ohms (x
1000)
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Page 49
Temperatur
e of
Thermistor
°C
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
-926.24670.9715
-824.85680.9386
-723.55690.9069
-622.33700.8766
-521.18710.8173
-420.09720.8192
-319.07730.7922
-218.10740.7662
-117.19750.7411
016.33760.7170
115.52770.6939
214.75780.6715
314.02790.6501
413.33800.6293
512.69810.6094
612.07820.5902
711.49830.5717
810.94840.5538
910.43850.5367
109.932860.5201
119.466870.5041
129.025880.4887
138.608890.4739
148.211900.4595
157.836910.4457
167.480920.4323
177.142930.4194
186.821940.4069
196.516950.3950
206.228960.3833
215.953970.3722
Resistance
K Ohms (x
1000)
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Page 50
Temperatur
e of
Thermistor
°C
225.692980.3613
235.444990.3508
245.2081000.3407
254.984
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
T2
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
°C
-40225.1366.623
-39212.8376.387
-38200.6386.162
-37189.3395.945
-36178.7405.738
-35168.8415.538
-34159.4425.347
-33150.6435.163
-32142.4444.987
-31134.7454.817
-30127.5464.655
-29120.6474.498
-28114.2484.348
-27108.2494.203
-26102.5504.064
-2597.20513.931
-2492.17523.803
-2387.44533.680
40
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
Resistance
K Ohms (x
1000)
Page 51
Temperatur
e of
Thermistor
°C
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
-2282.97543.561
-2178.77553.446
-2074.80563.336
-1971.05573.230
-1867.52583.127
-1764.19593.028
-1661.03602.933
-1558.06612.841
-1455.24622.753
-1352.58632.667
-1250.07642.585
-1147.68652.505
-1045.43662.428
-943.30672.354
-841.27682.283
-739.36692.214
-637.55702.147
-535.83712.082
-434.19722.020
-332.65731.960
-231.18741.902
-129.78751.846
028.49761.791
127.20771.739
226.01781.688
324.88791.639
423.80801.592
522.78811.546
621.81821.502
720.88831.459
820.00841.417
Resistance
K Ohms (x
1000)
41
Page 52
Temperatur
e of
Thermistor
°C
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
919.16851.377
1018.36861.338
1117.60871.300
1216.88881.264
1316.19891.229
1415.53901.195
1514.90911.162
1614.30921.129
1713.73931.098
1813.19941.068
1912.67951.039
2012.17961.011
2111.70970.9838
2211.24980.9572
2310.81990.9316
2410.401000.9066
2510.001010.8832
269.6221020.8604
279.2601030.8384
288.9131040.8170
298.5821050.7964
308.2651060.7762
317.9611070.7564
327.6701080.7374
337.3911090.7190
347.12411 00.7010
356.868
Resistance
K Ohms (x
1000)
42
Page 53
Check Procedure
1. Make sure the thermistor sensors installation
correctly
2. Disconnect thermistor from control board and
measure resistance.
3. Measure temperature at the thermistor.
4. Compare measured resistance/
temperature.Creadings to resistance/temperature
relationship
• Within 10% of the published resistance value-
Thermistor is good
• Not within 10% of the published resistancevalue -
Thermistor is defective.
43
Page 54
Water System Checklist
A water-related problem often causes the same
symptoms as a refrigeration system component
malfunction.
Water system problems must be identified and
eliminated prior to replacing refrigeration components.
Water area (evaporator) is dirty
• Clean as needed
Water inlet pressure not between 1.4 and 5.5 bar
• Install a water regulator valve or increase the water
pressure
Incoming water temperature is not between
1.7°C and 32.2°C
• If too hot, check the hot water line check valves in
other store equipment
Water filtration is plugged (if used)
• Install a new water filter
Hoses, fittings, etc., are leaking water
• Repair/replace as needed
Water inlet valve is stuck open or closed
• Clean/replace as needed
Water is spraying out of the sump trough area
• Stop the water spray
Uneven water flow across the evaporator
• Clean the ice machine
44
Page 55
Ice Production Check
The amount of ice a machine produces directly relates
to the operating water and air temperatures. This
means an ice machine with a 20°C outdoor ambient
temperature and 10.0°C water produces more ice than
the same model ice machine with a 32°C outdoor
ambient and 21°C water.
1. Determine the ice machine operating conditions:
Air temp entering condenser: ____°
Air temp around ice machine: ____°
Water temp entering sump trough: ____°
2. Refer to the appropriate 24-Hour Ice Production
Chart.
3. Use the operating conditions determined in Step 1
to find published 24 hr. ice production: ____
• Times are in minutes.
Example: 1 min., 15 sec. converts to 1.25 min.
(15 seconds ÷ 60 seconds = .25 minutes)
• Weights are in grams.
4. Perform an ice production check using the formula
below.
1._________
Freeze Time
2.1440
_________
Minutes in
24 Hrs.
3._________
Weight of One
Harvest
+_________
Harvest Time
_________
Total Cycle
Time
×_________
Cycles per Day
=_________
To t a l C y cl e
Time
_________
Cycles per Day
=_________
Actual 24-Hour
Production
Weighing the ice is the only 100% accurate check.
Compare the results of Step 3 with Step 2. Ice
production is normal when these numbers match
closely. If they match closely, determine if:
• Another ice machine is required.
Relocating the existing equipment to lower the load
conditions is required.
45
Page 56
Analyzing Discharge Pressure
1. Determine the ice machine operating conditions:
Air temp. entering condenser ______
Air temp. around ice machine ______
Water temp. entering sump trough ______
2. Refer to Cycle Times/24 Hour Ice Production/
Refrigeration Pressure Chart for ice machine being
checked.
3. Use the operating conditions determined in Step 1
to find the published normal discharge pressures.
Freeze Cycle ______
Harvest Cycle ______
Perform an actual discharge pressure check.
Freeze Cycle
PSIG
Beginning
of Cycle
Middle
of Cycle
End
of Cycle
____________________
____________________
____________________
Compare the actual discharge pressure (Step 3) with
the published discharge pressure (Step 2).
The discharge pressure is normal when the actual
pressure falls within the published pressure range for
the ice machine’s operating conditions. It is normal for
the discharge pressure to be higher at the beginning of
the freeze cycle (when load is greatest), then drop
throughout the freeze cycle.
Harvest Cycle
PSIG
46
Page 57
DISCHARGE PRESSURE HIGH CHECKLIST
Improper Installation
• Refer to “Installation/Visual Inspection Checklist”
Restricted Condenser Air Flow
• High inlet air temperature
• Condenser discharge air re-circulation
• Dirty condenser fins
• Defective fan motor
Improper Refrigerant Charge
• Overcharged
• Non-condensable in system
• Wrong type of refrigerant
Other
• High side refrigerant lines/component restricted
(before mid-condenser)
47
Page 58
FREEZE CYCLE DISCHARGE PRESSURE LOW
CHECKLIST
Improper Installation
• Refer to “Installation/Visual Inspection Checklist”
Improper Refrigerant Charge
• Undercharged
• Wrong type of refrigerant
Other
• High side refrigerant lines/component restricted
(before mid-condenser)
NOTE:
Do not limit your diagnosis to only the items
listed in the checklists.
48
Page 59
Analyzing Suction Pressure
The suction pressure gradually drops throughout the
freeze cycle. The actual suction pressure (and drop
rate) changes as the air and water temperature
entering the ice machine changes. These variables
also determine the freeze cycle times.
To analyze and identify the proper suction pressure
drop throughout the freeze cycle, compare the
published suction pressure to the published freeze
cycle time.
NOTE:
suction pressure. High or low discharge pressure may
be causing high or low suction pressure.
Analyze discharge pressure before analyzing
49
Page 60
Procedure
20
2.56
140
2.92
2.2
Step
1. Determine the ice
machine operating
conditions.
2A. Refer to “Cycle Time” and
“Operating Pressure”
charts for ice machine
model being checked.
Using operating
conditions from Step 1,
determine published
freeze cycle time and
published freeze cycle
suction pressure.
2B. Compare the published
freeze cycle time and
published freeze cycle
suction pressure. Develop
a chart.
3. Perform an actual suction
pressure check at the
beginning, middle and end
of the freeze cycle. Note
the times at which the
readings are taken.
4. Compare the actual
freeze cycle suction
pressure (Step 3) to the
published freeze cycle
time and pressure
comparison (Step 2B).
Determine if the suction
pressure is high, low or
acceptabl e.
Example Using UG040A Model Ice
Air temp. entering condenser:
32°C
Water temp. entering water fill valve:
21°C
39.28 minutes
Published Freeze cycle time:
2.92 to2.2 bar
Published Freeze cycle suction pressure:
Published Freeze Cycle Suction
In the example, the proper suction pressure
should be approximate ly 2.92 bar at 1 min ute;
Manifold gauges were connected to the
example ice machine and suction pressure
readings taken as follows:
Beginning of Freeze cycle:5bar (at 1 min.)
Middle of Freeze cycle:4 bar (at 20 min.)
End of Freeze cycle:3 bar (at 40 min.)
In this example, the suction pressure is
considered high throughout the freeze cycle.
It should have been:
Approximately 2.92 bar
(at 1 minute) – not 5 bar
Approximately 2.56 bar
(at 20 minutes) – not 4 bar
Approximately 2.2 bar
(at 40 minutes) – not 3 bar
Machine
Published Freeze Cycle Time
(minutes)
Pressure (bar)
2.56bar at 20 minutes; etc.
50
Page 61
SUCTION PRESSURE HIGH CHECKLIST
Improper Installation
• Refer to “Installation/Visual Inspection Checklist”
Discharge Pressure
• Discharge pressure is too high, and is affecting
suction pressure, refer to “Freeze Cycle Discharge
Pressure High Checklist”
• Refer to “Installation/Visual Inspection Checklist”
Discharge Pressure
• Discharge pressure is too low, and is affecting
suction pressure, refer to “Freeze Cycle Discharge
Pressure Low Checklist”
Improper Refrigerant Charge
• Undercharged
• Wrong type of refrigerant
Other
• Improper water supply over evaporator, refer to
“Water System Checklist”
• Loss of heat transfer from tubing on back side of
evaporator
• Restricted/plugged liquid line drier
• Restricted/plugged tubing or capillary tube in suction
side of refrigeration system
• TXV starving
• Moisture in refrigeration system
NOTE:
Do not limit your diagnosis to only the items
listed in the checklists.
52
Page 63
Discharge Line Temperature Analysis
General
Compressor discharge line temperature on a normally
operating ice machine steadily increases throughout
the freeze cycle. Comparing the temperatures over
several cycles will result in a consistent maximum
discharge line temperature.
Ambient air temperatures affect the maximum
discharge line temperature.
Higher ambient air temperatures at the condenser =
higher discharge line temperatures at the compressor.
Lower ambient air temperatures at the condenser =
lower discharge line temperatures at the compressor.
Regardless of ambient temperature, the freeze cycle
discharge line temperature will be higher than 71°C on
a normally operating ice machine.
Procedure
Connect a temperature probe on the compressor
discharge line within 6" of the compressor.
Observe the discharge line temperature for the last ten
minutes of the freeze cycle and record the maximum
discharge line temperature.
53
Page 64
DISCHARGE LINE TEMPERATURE ABOVE 71°C AT
END OF FREEZE CYCLE:
Ice machines that are operating normally will have
consistent maximum discharge line temperatures
above 71°C.
DISCHARGE LINE TEMPERATURE BELOW 71°C AT
END OF FREEZE CYCLE:
Ice machines that have a flooding expansion valve will
have a maximum discharge line temperature that
decreases each cycle.
Verify the expansion valve sensing bulb is 100%
insulated and sealed airtight. Condenser air contacting
an incorrectly insulated sensing bulb will cause
overfeeding of the expansion valve.
Verify the expansion valve sensing bulb is positioned
and secured correctly.
54
Page 65
Component Check Procedures
ON/OFF/WASH-FILL T OGGLE SWITCH
Function
The switch is used to place the ice machine in ON,
OFF or WASH mode of operation.
Specifications
Double-pole, Double-throw switch.
Check Procedure
1. Inspect the toggle switch for correct wiring.
2. Isolate the toggle switch by disconnecting all wires
from the switch.
3. Check across the toggle switch terminals using a
calibrated ohmmeter. Note where the wire numbers
are connected to the switch terminals, or refer to
the wiring diagram to take proper readings.
Switch
Setting
ON
WASH
OFF
TerminalsOhm Reading
5-6Open
5-4Closed
2-1Closed
2-3Open
5-4Open
5-6Closed
2-3Closed
2-1Open
2-3Open
2-1Open
5-6Open
5-4Open
Replace the toggle switch if ohm readings do not
match all three-switch settings.
55
Page 66
BIN THERMISTOR (T3)
Function
The bin thermistor stops the ice machine when the bin
is full. When ice cubes contact the bin thermistor bulb
holder, the bin thermistor opens and stops the ice
machine. When ice cubes no longer contact the bin
thermistor bulb holder, the bin thermistor closes and
the ice machine starts.
The bin thermistor “temperature setting” determined
by the point of T2(liquid line thermistor) of when T1
(sump water thermistor) come down 2 °C, refer to the
Specifications Charts below for clearance.
Specifications
UG40/UG50/YG65
T1 (°C)T2 (°C)
≤2.0T2≤28≤1.5≥2.0
≤2.028<T2≤56≤2.0≥3.5
≤2.056<T2≤3.0≥4.5
Shut down
(T3)
Go back
(T3)
UG18/UG20/UG30
T1 (°C)T2 (°C)
≤2.0T2≤32≤1.7≥2.2
≤2.032<T2≤51≤2.2≥3.7
≤2.051<T2≤3.0≥4.5
Shut down
(T3)
Go back
(T3)
UG80
T1 (°C)T2 (°C)
≤2.0T2≤37≤1.5≥2.0
≤2.037<T2≤56≤2.0≥3.5
≤2.056<T2≤3.0≥4.5
56
Shut down
(T3)
Go back
(T3)
Page 67
Check Procedure
!
Warning
Disconnect electrical power to the entire ice
machine before proceeding.
Make sure bulb is inserted correctly 35.5 cm in the
bulb well. Disconnect the wires from the bin thermostat
and check the resistance across the terminals.
No Ice on BulbIce on BulbResult
Closed (O)Open (OL)Thermostat good
Open (OL)Closed (O)
Replace
thermostat
NOTE:
After covering/uncovering the bulb holder with
ice, wait at least three minutes to allow the thermostat
to react. (Open/Close)
57
Page 68
SUMP WATER THERMISTOR (T1)& LIQUID LINE
THERMISTOR(T2)
Function
The sump water thermistor sensor immersed in water
to detect sump temperature.The value supplied to the
control board is
used to Initiates freeze cycle
The liquid line thermistor senses the refrigeration
system liquid line temperature. This is used in
conjunction with the control board to determine the
length of the freeze and harvest cycles
.
Specifications
The sump water thermostor :
R2.0°C ±0.5°C = 14.75Kohm ±1%
The liquid line thermistor:
R25°C±0.5°C = 10Kohm ±1%
Check Procedure
1. Make sure the thermistor sensors installation
correctly
2. Disconnect thermistor from control board and
measure resistance.
3. Measure temperature at the thermistor.
4. Compare measured resistance/
temperature.Creadings to resistance/temperature
relationship
Within 10% of the published resistance valueThermistor is good
58
Page 69
Temperature/Resistance Chart
Important
If the ohmmeter reads “OL,” check the scale setting
on the meter before assuming the thermistor is bad.
TI &T3
Temperatur
e of
Thermistor
°C
-50344.6264.771
-49320.5274.567
-48298.2284.375
-47277.6294.190
-46258.7304.016
-45241.1313.849
-44224.8323.690
-43209.8333.538
-42195.9343.394
-41183.0353.256
-40171.0363.124
-39159.9372.999
-38149.5382.879
-37140.0392.764
-36131.1402.656
-35122.8412.551
-34115.1422.452
-33108.0432.356
-32101.2442.266
-3195.03452.179
-3089.24462.095
-2983.83472.016
-2878.79481.940
-2774.09491.867
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
Resistance
K Ohms (x
1000)
59
Page 70
Temperatur
e of
Thermistor
°C
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
-2669.70501.797
-2565.58511.731
-2461.75521.667
-2358.16531.606
-2254.81541.547
-2151.66551.491
-2048.72561.437
-1945.97571.385
-1843.39581.336
-1740.96591.289
-1638.69601.243
-1536.56611.200
-1434.56621.158
-1332.68631.117
-1230.92641.079
-1129.25651.041
-1027.70661.006
-926.24670.9715
-824.85680.9386
-723.55690.9069
-622.33700.8766
-521.18710.8173
-420.09720.8192
-319.07730.7922
-218.10740.7662
-117.19750.7411
016.33760.7170
115.52770.6939
214.75780.6715
314.02790.6501
413.33800.6293
Resistance
K Ohms (x
1000)
60
Page 71
Temperatur
e of
Thermistor
°C
512.69810.6094
612.07820.5902
711.49830.5717
810.94840.5538
910.43850.5367
109.932860.5201
119.466870.5041
129.025880.4887
138.608890.4739
148.211900.4595
157.836910.4457
167.480920.4323
177.142930.4194
186.821940.4069
196.516950.3950
206.228960.3833
215.953970.3722
225.692980.3613
235.444990.3508
245.2081000.3407
254.984
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
Resistance
K Ohms (x
1000)
T2
Temperatur
e of
Thermistor
°C
-40225.1366.623
-39212.8376.387
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
Resistance
K Ohms (x
1000)
61
Page 72
Temperatur
e of
Thermistor
°C
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
-38200.6386.162
-37189.3395.945
-36178.7405.738
-35168.8415.538
-34159.4425.347
-33150.6435.163
-32142.4444.987
-31134.7454.817
-30127.5464.655
-29120.6474.498
-28114.2484.348
-27108.2494.203
-26102.5504.064
-2597.20513.931
-2492.17523.803
-2387.44533.680
-2282.97543.561
-2178.77553.446
-2074.80563.336
-1971.05573.230
-1867.52583.127
-1764.19593.028
-1661.03602.933
-1558.06612.841
-1455.24622.753
-1352.58632.667
-1250.07642.585
-1147.68652.505
-1045.43662.428
-943.30672.354
-841.27682.283
Resistance
K Ohms (x
1000)
62
Page 73
Temperatur
e of
Thermistor
°C
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
-739.36692.214
-637.55702.147
-535.83712.082
-434.19722.020
-332.65731.960
-231.18741.902
-129.78751.846
028.49761.791
127.20771.739
226.01781.688
324.88791.639
423.80801.592
522.78811.546
621.81821.502
720.88831.459
820.00841.417
919.16851.377
1018.36861.338
1117.60871.300
1216.88881.264
1316.19891.229
1415.53901.195
1514.90911.162
1614.30921.129
1713.73931.098
1813.19941.068
1912.67951.039
2012.17961.011
2111.70970.9838
2211.24980.9572
2310.81990.9316
Resistance
K Ohms (x
1000)
63
Page 74
Temperatur
e of
Thermistor
°C
Resistance
K Ohms (x
1000)
Temperatur
e of
Thermistor
2410.401000.9066
2510.001010.8832
269.6221020.8604
279.2601030.8384
288.9131040.8170
298.5821050.7964
308.2651060.7762
317.9611070.7564
327.6701080.7374
337.3911090.7190
347.12411 00.7010
356.868
Resistance
K Ohms (x
1000)
64
Page 75
HIGH PRESSURE CUTOUT (HPCO) CONTROL
!
Warning
Water Cooled Only
FUNCTION
Stops the ice machine if subjected to excessive highside pressure.
The HPCO control is normally closed, and opens on a
rise in discharge pressure.
SPECIFICATIONS
ModelCut-outCut-in:
UG030W300 psig ± 10 150 psig ± 10
UG050W450 psig± 10 300 psig± 10
CHECK PROCEDURE
1. Set ON/OFF/WASH switch to OFF.
2. Connect manifold gauges.
3. Hook voltmeter in parallel across the HPCO,
leaving wires attached.
4. Close the valve to the water condenser inlet.
5. Set ON/OFF/WASH switch to ON.
6. No water flowing through the condenser will cause
the HPCO control to open because of excessive
pressure. Watch the pressure gauge and record the
cut-out pressure.
If discharge pressure exceeds 310 psig (UG030) or
460psig(UG050) and the HPCO control does not cut
out, set ON/OFF/WASH switch to OFF to stop ice
machine operation.
Replace the HPCO control if it:
• Will not reset (below 150 psig [UG030];below 300
psig [UG050])
• Does not open at the specified cut-out point
65
Page 76
HOT GAS VALVE
General
The hot gas valve is an electrically operated valve that
opens when energized, and closes when deenergized.
Normal Operation
The valve is de-energized (closed) during the freeze
cycle and energized (open) during the harvest cycle.
The valve is positioned between the compressor and
the evaporator and performs two functions:
7. Prevents refrigerant from entering the evaporator
during the freeze cycle.
The hot gas valve is de-energized (closed)
preventing refrigerant flow from the receiver into
the evaporator.
8. Allows refrigerant vapor to enter the evaporator in
the harvest cycle.
During the harvest cycle, the hot gas valve is
energized (open) allowing refrigerant gas from the
discharge line of the compressor to flow into the
evaporator. The heat is absorbed by the evaporator
and allows release of the ice slab.
Exact pressures vary according to ambient
temperature and ice machine model. Harvest
pressures can be found in the “Cycle Time/24 Hour Ice
Production/Refrigerant Pressure Charts in this book.
66
Page 77
Hot Gas Valve Analysis
The valve can fail in two positions:
• Valve will not open in the harvest cycle.
• Valve remains open during the freeze cycle.
VALVE WILL NOT OPEN IN THE HARVEST CYCLE:
Although the coil is energized in the harvest cycle, the
evaporator temperature/pressure remains unchanged
from the freeze cycle.
VALVE REMAINS OPEN IN THE FREEZE CYCLE:
Symptoms of a hot gas valve remaining partially open
during the freeze cycle can be similar to symptoms of
an expansion valve, Capillary tube or compressor
problem. Symptoms are dependent on the amount of
leakage in the freeze cycle.
A small amount of leakage will cause increased freeze
times. As the amount of leakage increases, the length
of the freeze cycle increases.
Refer to the Parts Manual for proper valve application.
If replacement is necessary, use only “original”
Manitowoc replacement parts.
67
Page 78
Use the following procedure and table to help
Important
!
Warning
determine if a hot gas valve is remaining partially open
during the freeze cycle.
1. Wait five minutes into the freeze cycle.
2. Feel the inlet of the hot gas valve.
Feeling the hot gas valve outlet or across the hot
gas valve itself will not work for this comparison. The
hot gas valve outlet is on the suction side (cool
refrigerant). It may be cool enough to touch even if
the valve is leaking.
3. Feel the compressor discharge line.
The inlet of the hot gas valve and the compressor
discharge line could be hot enough to burn your
hand. Just touch them momentarily.
4. Compare the temperature of the inlet of the hot gas
valves to the temperature of the compressor
discharge line.
68
Page 79
Examples of hot gas valve inlet/compressor
discharge line temperature comparison
FindingsComments
The inlet of the hot gas
valve is cool enough to
touch and the
compressor discharge
line is hot.
The inlet of the hot gas
valve is hot and
approaches the
temperature of a hot
compressor discharge
line.
Both the inlet of the hot
gas valve and the
compressor discharge
line are cool enough to
touch.
This is normal as the discharge
line should always be too hot to
touch and the hot gas valve inlet,
although too hot to touch during
harvest, should be cool enough
to touch after 5 minutes into the
freeze cycle.
This is an indication something is
wrong, as the hot gas valve inlet
did not cool down during the
freeze cycle. If the compressor
dome is also entirely hot, the
problem is not a hot gas valve
leaking, but rather something
causing the compressor (and the
entire ice machine) to get hot.
This is an indication something is
wrong, causing the compressor
discharge line to be cool to the
touch. This is not caused by a hot
gas valve leaking.
69
Page 80
This Page Intentionally Left Blank
70
Page 81
Refrigerant
Important
Important
RECOVER/EVACUATION/CHARGING
Normal Procedures
Do not purge refrigerant to the atmosphere. Capture
refrigerant using recovery equipment. Follow the
manufacturer’s recommendations.
Manitowoc Ice, Inc. assumes no responsibility for
the use of contaminated refrigerant. Damage
resulting from the use of contaminated refrigerant is
the sole responsibility of the servicing company.
Replace the liquid line drier before evacuating and
recharging. Use only a Manitowoc (O.E.M.) liquid
line filter drier to prevent voiding the warranty.
Connections
1. Suction side of the compressor through the suction
service valve.
2. Discharge side of the compressor through the
discharge service valve.
–71–
Page 82
Self-Contained Recovery/Evacuation
Place the toggle switch in the OFF position.
Install manifold gauges (with low loss fittings), scale,
and recovery unit or two-stage vacuum pump.
Open (backseat) the high and low side on manifold
gauges.
Perform recovery or evacuation:
A. Recovery: Operate the recovery unit as directed by
the manufacturer’s instructions.
B. Evacuation prior to recharging: Pull the system
down to 500 microns. Then, allow the pump to run
for an additional half hour. Turn off the pump and
perform a standing vacuum leak check.
NOTE: Check for leaks using a halide or electronic
leak detector after charging the ice machine.
Follow the Charging Procedures on the next page.
–72–
Page 83
Charging Procedures
Important
The charge is critical on all Manitowoc ice machines.
Use a scale to ensure the proper charge is installed.
1. Be sure the toggle switch is in the OFF position.
2. Close the vacuum pump valve and the low side
manifold gauge valve.
3. Open the high side manifold gauge valve.
4. Open the refrigerant cylinder and add the proper
refrigerant charge (shown on nameplate) through
the discharge service valve.
5. Let the system “settle” for 2 to 3 minutes.
6. Place the toggle switch in the ICE position.
7. Close the high side on the manifold gauge set. Add
any remaining vapor charge through the suction
service valve (if necessary).
NOTE: Manifold gauges must be removed properly to
ensure that no refrigerant contamination or loss
occurs.
8. Make sure all vapor in the charging hoses is drawn
into the ice machine before disconnecting.
a. Run the ice machine in freeze cycle.
b. Disconnect the high side service valve at the ice
machine.
c. Open the high and low side valves on the
manifold gauge set. Any refrigerant in the lines
will be pulled into the low side of the system.
d. Allow the pressures to equalize while the ice
machine is in the freeze cycle.
e. Disconnect the low side service valve at the ice
machine.
9. Install the caps on the refrigeration access valves.
–73–
Page 84
SYSTEM CONTAMINATION CLEANUP
Important
General
This section describes the basic requirements for
restoring contaminated systems to reliable service.
Manitowoc Ice, Inc. assumes no responsibility for
the use of contaminated refrigerant. Damage
resulting from the use of contaminated refrigerant is
the sole responsibility of the servicing company.
DETERMINING SEVERITY OF CONTAMINATION
System contamination is generally caused by either
moisture or residue from compressor burnout entering
the refrigeration system.
Inspection of the refrigerant usually provides the first
indication of system contamination. Obvious moisture
or an acrid odor in the refrigerant indicates
contamination.
If either condition is found, or if contamination is
suspected, use a Total Test Kit from Totaline or a
similar diagnostic tool. These devices sample
refrigerant, eliminating the need to take an oil sample.
Follow the manufacturer’s directions.
If a refrigerant test kit indicates harmful levels of
contamination, or if a test kit is not available, inspect
the compressor oil.
1. Remove the refrigerant charge from the ice
machine.
2. Remove the compressor from the system.
3. Check the odor and appearance of the oil.
4. Inspect open suction and discharge lines at the
compressor for burnout deposits.
5. If no signs of contamination are present, perform an
acid oil test to determine the type of cleanup
required.
–74–
Page 85
Contamination/Cleanup Chart
Symptoms/Findings
No symptoms or suspicion of
contamination.
Moisture/Air Contamination
symptoms. Refrigeration
system open to atmosphere for
longer than 15 minutes.
Refrigeration test kit and/or acid
oil test shows contamination.
No burnout deposits in open
compressor lines.
Mild Compressor Burnout
symptoms. Oil appears clean
but smells acrid. Refrigeration
test kit or acid oil test shows
harmful acid content. No
burnout deposits in open
compressor lines.
Severe Compressor Burnout
symptoms. Oil is discolored,
acidic, and smells acrid.
Burnout deposits found in the
compressor, lines, and other
components.
Required Cleanup
Procedure
Normal evacuation/
recharging procedure
Mild contamination
cleanup procedure
Mild contamination
cleanup procedure
Severe contamination
cleanup procedure
–75–
Page 86
MILD SYSTEM CONTAMINATION CLEANUP
Important
Procedure
1. Replace any failed components.
2. If the compressor is good, change the oil.
3. Replace the liquid line drier.
NOTE: If the contamination is from moisture, use heat
lamps during evacuation. Position them at the
compressor, condenser and evaporator prior to
evacuation. Do not position heat lamps too close to
plastic components, or they may melt or warp.
Dry nitrogen is recommended for this procedure.
This will prevent CFC release.
Follow the normal evacuation procedure, except
replace the evacuation step with the following:
A. Pull vacuum to 1000 microns. Break the vacuum
with dry nitrogen and sweep the system. Pressurize
to a minimum of .35 bar.
B. Pull vacuum to 500 microns. Break the vacuum
with dry nitrogen and sweep the system. Pressurize
to a minimum of .35 bar.
C. Change the vacuum pump oil.
D. Pull vacuum to 500 microns. Run the vacuum pump
for 1/2 hour on self-contained models, 1 hour on
remotes.
NOTE: Perform a pressure test to be sure there are no
leaks.
Charge the system with the proper refrigerant to the
nameplate charge.
Operate the ice machine.
–76–
Page 87
SEVERE SYSTEM CONTAMINATION CLEANUP
Important
PROCEDURE
1. Remove the refrigerant charge.
2. Remove the compressor.
3. Wipe away any burnout deposits from suction and
discharge lines at compressor.
4. Sweep through the open system with dry nitrogen.
Refrigerant sweeps are not recommended, as they
release CFC’s into the atmosphere.
5. Install a new compressor and new start
components.
6. Install suction line filter-drier in front of compressor.
7. Install a new liquid line drier.
–77–
Page 88
Important
Dry nitrogen is recommended for this procedure.
This will prevent CFC release.
A. Pull vacuum to 1000 microns. Break the vacuum
with dry nitrogen and sweep the system. Pressurize
to a minimum of .35 bar.
B. Change the vacuum pump oil.
C. Pull vacuum to 500 microns. Break the vacuum
with dry nitrogen and sweep the system. Pressurize
to a minimum of .35 bar.
D. Change the vacuum pump oil.
E. Pull vacuum to 500 microns. Run the vacuum pump
for 1 hour additional hour.
Charge the system with the proper refrigerant to the
nameplate charge.
Operate the ice machine for one hour. Then, check
the pressure drop across the suction line filter-drier.
F. If the pressure drop is less than .14 bar, the filter-
drier should be adequate for complete cleanup.
G. If the pressure drop exceeds .14 bar, change the
suction line filter-drier and the liquid line drier.
Repeat until the pressure drop is acceptable.
Operate the ice machine for 48-72 hours. Replace
the suction line and liquid line drier if necessary.
–78–
Page 89
FILTER-DRIERS
Important
Liquid Line Filter Drier
The filter-drier used on Manitowoc ice machines are
manufactured to Manitowoc specifications.
The difference between a Manitowoc drier and an offthe-shelf drier is in filtration. A Manitowoc drier has
dirt-retaining filtration, with fiberglass filters on both the
inlet and outlet ends. This is very important because
ice machines have a back-flushing action that takes
place during every harvest cycle.
A Manitowoc filter-drier has a very high moisture
removal capability and a good acid removal capacity.
The liquid line drier is covered as a warranty part.
The liquid line drier must be replaced any time the
system is opened for repair.
–79–
Page 90
TOTAL SYSTEM REFRIGERATION CHARGE
Important
This information is for reference only. Refer to the
ice machine serial number tag to verify the system
charge. Serial plate information overrides
information listed on this page.
Model
UG018AG-251G150R134A
UG020AG-251G178R134A
UG030AG-251G230R134A
UG040AG-251G
UG050AG-251G210R404A
UG065AG-251G360R404A
UG080AG-251G290R404A
UG020AG-261Z178R134A
UG030AG-261Z
UG040AG-261Z280R404A
UG050AG-261Z184R404A
UG065AG-261Z360R404A
UG080AG-261Z290R404A
UG030WG-251G140R134A
UG050WG-251G210R404A
UG030AG-161Z178R134A
UG050AG-161Z184R404A
Refrigerant
Charge (grams)
260R404A
178R134A
Refrigerant
Type
–80–
Page 91
Cycle Times/24 Hour Ice Production
and Refrigerant Pressure Charts
These charts are used as guidelines to verify correct
ice machine operation.
Accurate collection of data is essential to obtain the
correct diagnosis.
• Refer to “OPERATIONAL ANALYSIS CHART” for
the list of data that must be collected for refrigeration
diagnostics. This list includes: before beginning
service, ice production check, installation/visual
inspection, water system checklist, ice formation
pattern, safety limits, comparing evaporator inlet/
outlet temperatures, hot gas valve analysis,
discharge and suction pressure analysis.
• Ice production checks that are within 10% of the
chart are considered normal. This is due to
variances in water and air temperature. Actual
temperatures will seldom match the chart exactly.
• Zero out manifold gauge set before obtaining
pressure readings to avoid misdiagnosis.
• Discharge and suction pressure are highest at the
beginning of the cycle. Suction pressure will drop
throughout the cycle. Verify the pressures are within
the range indicated.
–81–
Page 92
UG18A SELF-CONTAINED AIR-COOLED — STANDARD CUBE
NOTE: These characteristics may vary depending on operating conditions.
Cycle Times
Freeze Time + Harvest Time = Total Cycle Time
–82–
Air Temp.
Entering
Condenser
°C
1018.82-20.77
2119.99-24.820.58-25.89
3234.34-37.42
3849.68-53.50
4360.56-67.07
10152132
Freeze Time
Water Temperature °C
Times in minutes.
Harvest Time
1.4-3.5 min.
Page 93
UG18A SELF-CONTAINED AIR-COOLED — STANDARD CUBE (Continued)
24 Hour Ice Production