Page 1
USE0050 Ice Machine Technician’s Handbook This manual is updated as new information and models are released. Visit our website for the latest manual. www.manitowocice.com Part Number STH111 Rev 01 08/23...
Safety Notices Read these precautions to prevent personal injury: • Read this manual thoroughly before operating, installing or performing maintenance on the equipment. Failure to follow instructions in this manual can cause property damage, injury or death. • Routine adjustments and maintenance procedures outlined in this manual are not covered by the warranty.
Safety Definitions DANGER Indicates a hazardous situation that, if not avoided, may result in death or serious injury. This applies to the most extreme situations. Warning Indicates a hazardous situation that, if not avoided, may result in death or serious injury. Caution Indicates a hazardous situation which, if not avoided, may result in minor or moderate injury.
Page 5
Warning Follow these electrical requirements during installation of this equipment. • All field wiring must conform to all applicable codes of the authority having jurisdiction. It is the responsibility of the end user to provide the disconnect means to satisfy local codes. Refer to rating plate for proper voltage.
Page 6
Warning Follow these precautions to prevent personal injury during installation of this equipment: • Installation must comply with all applicable equipment fire and health codes with the authority having jurisdiction. • To avoid instability the installation area must be capable of supporting the combined weight of the equipment and product.
Page 7
Warning Follow these precautions to prevent personal injury while operating or maintaining this equipment. • Legs or casters must be installed and the legs/casters must be screwed in completely. When casters are installed the mass of this unit will allow it to move uncontrolled on an inclined surface.
Page 8
Warning Follow these precautions to prevent personal injury while operating or maintaining this equipment. • Objects placed or dropped in the bin can affect human health and safety. Locate and remove any objects immediately. • Never use sharp objects or tools to remove ice or frost.
Page 9
DANGER Follow these precautions to prevent personal injury during use and maintenance of this equipment: • It is the responsibility of the equipment owner to perform a Personal Protective Equipment Hazard Assessment to ensure adequate protection during maintenance procedures. • Do Not Store Or Use Gasoline Or Other Flammable Vapors Or Liquids In The Vicinity Of This Or Any Other Appliance.
Page 10
Warning Follow these precautions to prevent personal injury during use and maintenance of this equipment: • It is the responsibility of the site supervisor to ensure that operators fully understand the dangers inherent in operating this equipment. • Turn off and lockout all utilities (gas, electric, water) according to approved practices during maintenance or servicing.
General Information Model Numbers This manual covers the following models: Self-contained Air-cooled USE0050A How to Read a Model Number Cube Size Capacity Condenser Series Type U S E - 0050 A E - R134 A - Air-cooled S - Square Warning An ice machine contains high voltage electricity and refrigerant charge.
Model/Serial Number Location These numbers are required when requesting information from your local Manitowoc Distributor, Service Representative, or Manitowoc Ice. The model/serial number data plate is located in the evaporator compartment and on the back of the ice machine. Warranty For warranty information visit: www.manitowocice.com/Service/Warranty...
Installation Location of Ice Machine 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.
Ice Machine Clearance Requirements Self-contained Air-cooled Top/Sides 0" (0 mm)* Back 0" (0 mm)* *The ice machine may be built into a cabinet. Leveling the Ice Machine 1. Screw the legs onto the bottom of the ice machine. 2. Screw the foot of each leg in as far as possible. Caution The legs must be screwed in tightly to prevent them from bending.
Electrical Requirements Voltage The maximum allowable voltage variation is ±10% of the rated voltage on the ice machine model/serial number plate at start-up (when the electrical load is highest). Fuse/Circuit Breaker A separate fuse/circuit breaker must be provided for each ice machine.
Water pressure must remain between 20 and 80 psig (14 to 55 bar). If water pressure exceeds the maximum recommended pressure (80 psi - 55 bar), obtain a water pressure regulator from your Manitowoc distributor. • Install a water shut-off valve for ice making potable water.
DRAIN CONNECTIONS Follow these guidelines when installing drain lines to prevent drain water from flowing back into the ice machine and storage bin: • Drain lines must have a 1.5-inch drop per 5 feet of run (2.5 cm per meter), and must not create traps. •...
Page 22
Water Supply and Drain Line Sizing/Connections Part Number STH111 Rev 01 08/23...
Use only Manitowoc approved Ice Machine Descaler (9405463) and Sanitizer (9405653). Using a non Manitowoc descaler or sanitizer may result in bodily harm and/or cause damage to the ice machine that is not covered under the warranty. Do not use descaler or sanitizer quantities that exceed the amounts listed in this manual.
CAUTION Damage to the ice machine evaporator caused by incorrect chemical usage is not covered by the warranty. Use Manitowoc Ice Machine Descaler (part number 9405463) and Sanitizer (part number 9405653) only. Part Number STH111 Rev 01 08/23...
Remedial Descaling Procedure This procedure allows in place descaling of all surfaces that come in contact with the water system. The ice machine requires disassembly and descaling/sanitizing a minimum of once every 6 months. The quality of your potable water supply may require more frequent cleaning intervals.
Page 26
Remove all ice from the bin. Step 2 Prepare 4 oz (1/2 cup) of undiluted Manitowoc Step 3 Ice Machine Descaler (part number 9405463 only) in a container that will fit easily under the lifted water curtain.
Page 27
Wait until the water pump sprays water onto Step 9 the evaporator(approximately 3 minutes) then add the prepared Manitowoc Sanitizer by lifting the water curtain and pouring directly into the spray area. The ice machine will automatically time out a ten minute sanitizing cycle, followed by five rinse cycles.
This entire cycle lasts approximately 30 minutes. Disconnect electric power to the ice machine. Step 7 Mix 16 oz (2 cups) Manitowoc Descaler with 2 Step 8 gal of warm water. Model Descaler Amount...
Page 29
Remove the following components for descaling Step 9 and sanitizing: Tongs, Tong Holder, Water Curtain, Ice Ramp, Water Pump, and Spray Nozzle Assembly. Refer to "Removal of Parts for Descaling/Sanitizing" on page 31. Take all removed components to a sink for Step 10 descaling.
Page 30
Clean button. Wait until the water pump sprays water onto the evaporator (approximately 3 minutes) then add 1/2 oz (1 tablespoon) of undiluted Manitowoc Sanitizer by lifting the water curtain and pouring directly into the spray area. This entire cycle lasts approximately 30 minutes.
See the following pages for removal procedures for these parts. Warning Wear rubber gloves and safety goggles (and/or face shield) when handling Manitowoc Ice Machine Descaler or Sanitizer. 4. Soak the removed part(s) in a properly mixed solution of descaler.
9. Use the sanitizing solution and a spray bottle, sponge or cloth to sanitize (wipe) the interior of the ice machine and bin. 10. Do not rinse sanitized areas when using Manitowoc Sanitizer. 11. Install the removed parts. 12. Turn on the water and electrical supply TOP COVER 1.
Page 33
Water Curtain The water curtain is designed to keep the spraying water from escaping the evaporator compartment. TO REMOVE JUST THE WATER CURTAIN: 1. Grasp one end of the water curtain and lift up. 2. Pivot water curtain and disengage remaining end. 3.
Page 34
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, with the front edge inside the water trough. Spray nozzles must be align with the spray holes or spray water will fall into the bin.
Page 35
Water Trough 1. Depress tabs on right and left side of the water trough. 2. Allow front of water trough to drop as you pull forward to disengage the rear pins. Spray Bar, Water Pump and Hose 1. Remove spray bar clamp and spray bar. 2.
Page 36
Spray Bar Disassembly The spray bar supplies water to the individual ice making 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 evaporator bucket.
Page 37
Bin Light If the ice machine is shut down for a long period of time the bin light cover must be cleaned and sanitized. The light is provided for your convenience. If you experience operational problems with the light a replacement appliance bulb can be obtained from your local hardware store.
ICE MACHINE INSPECTION Check all water fittings and lines for leaks. Also, make sure the refrigeration tubing is not rubbing or vibrating against other tubing, panels, etc. Do not put anything (boxes, etc.) in front of the ice machine. There must be adequate airflow through and around the ice machine to maximize ice production and ensure long component life.
Removal from Service/Long Term Storage/ Winterization Perform a descaling and sanitizing procedure to Step 1 prevent mildew growth. Disconnect the electric power at the circuit Step 2 breaker or the electric service switch. Turn off the water supply. Step 3 Remove the water from the water trough.
Page 40
THIS PAGE INTENTIONALLY LEFT BLANK Part Number STH111 Rev 01 08/23...
Operation Ice Making Sequence of Operation Press to Repeat Daily Reset Water Filter Hours Service Power Ice Delay Clean FUNCTIONS Power Button (Blue) Pressing the “Power” button once will energize the ice machine and blue Power light. Pressing the “Power” button a second time will de-energize the ice machine.
ICE DELAY START Pressing the “Ice Delay” button will initiate a delay cycle. The ice machine will not run until the delay time expires. NOTE: The power button must be on to adjust delay start. • Pressing the ice delay button once will energize the 2 hour light and initiate a two hour delay period.
Page 43
EXAMPLE Setting a daily 4 hour delay from 1 pm to 5 pm. At 1 pm perform steps 1 through 4 above. The 4 hour delay light will blink every 3 seconds to indicate it is in a delay period. After 5 pm the ice machine will fill the bin as needed.
Sequence of Operation Depending on ambient conditions and cold water supply temperature, the ice making process will take approximately 45-105 minutes. Initial Start-Up or Start-Up After Automatic Shut- Off: Step 1 Water Purge/Refrigeration Equalization Before the compressor starts, the harvest valve and dump valve will energize for 15 seconds to equalize pressure in the refrigeration system and purge old water from the system.
Page 45
Harvest Sequence Step 5 Water Purge The water pump, dump valve, water inlet valve remain on for 45 seconds, then shutoff. Step 6 Harvest The evaporator is warmed, allowing the cubes to release from the evaporator, pass through the water curtain and drop into the storage bin.
Service Limits Service limits protect the machine from major system failures. The service LED will flash when one of the five service limits are exceeded. When the service button is pressed the LED will flash the corresponding number for the fault condition. For example if service limit 2 occurs the service light will flash twice.
Troubleshooting PROBLEM CHECKLIST Problem Possible Cause Correction Replace the fuse/reset the No electrical power to breaker/turn on the main the ice machine. switch/plug power cord into receptacle. Ice machine does Ice machine needs to Press the On/Off button to not operate. be turned on.
Page 50
Problem Possible Cause Correction Test the quality of the Poor incoming water incoming water and quality. make appropriate filter recommendations. Ice quality is Water filtration is poor. Replace the filter. poor (soft or not Descale and sanitize the ice clear). Ice machine is dirty.
ANALYZING WHY THE MACHINE TURNED OFF Service Limits Service limits stop the ice machine if conditions arise which could cause a major component failure. The service LED will flash when one of five service limits are exceeded. When the service button is pressed the LED will flash the corresponding number for the fault condition.
Page 52
SERVICE LIMIT 2: LONG HARVEST CYCLE. 2 FLASHES If the maximum harvest is reached for 3 consecutive cycles (7 minutes) the ice machine will shut down and the power LED will turn OFF. Possible Causes: • Closed/Stuck Bin Switch. • Dirty Evaporator.
Page 53
SERVICE LIMIT 4: CONDENSATE PUMP FAULT. 4 FLASHES If the float switch in the condensate pump is open, or the jumper in the wire harness in the ice machine is not in place the ice machine will shut down. Possible Causes: •...
CONTROL BOARD TEST MODE NOTE: The water curtain/bin switch can be open or closed and does not effect the operation of the test mode. To enter the test mode press and hold the test switch on the control board for 3 seconds. The control board test mode performs the following functions for a 2 minute time period: •...
DIAGNOSING AN ICE MACHINE THAT WILL NOT RUN Warning High (line) voltage is applied to the control board at all times. 1. Verify primary voltage is supplied to the ice machine. 2. Test for line voltage on the 9 pin connector wires number 39 &...
DIAGNOSING AN ICE MACHINE THAT DOES NOT CYCLE INTO HARVEST OR WILL NOT RELEASE THE ICE 1. Verify the harvest float is closed. Refer to “Float Switch” on page 72. 2. Verify evaporator temperature is below 10°F. 3. Verify the evaporator thermistor is operating correctly.
DIAGNOSING AN ICE MACHINE THAT CYCLES INTO HARVEST PREMATURELY 1. Verify the harvest float valve is open. Replace if closed in the up position or erratic when opened/closed repeatedly. 2. Verify evaporator thermistor value matches the evaporator temperature and is above 10°F. Refer to “Evaporator Thermistor”...
ELIMINATE ALL NON REFRIGERATION PROBLEMS BEFORE DIAGNOSING THE REFRIGERATION SYSTEM. • Perform a visual inspection for clearances, drains, dirty condenser/filter and water filter replacement. • Verify water spray is even across the entire evaporator. • Run an ice production check - Ice production checks within 10% are considered normal.
WATER SYSTEM CHECKLIST A water-related problem often causes the same symptoms as a refrigeration system component malfunction. Example: Water loss during the freeze cycle, a system low on charge, and a restricted TXV have similar symptoms. Water system problems must be identified and eliminated prior to replacing refrigeration components.
ICE CUBE PATTERN Ice cube formation is helpful in ice machine diagnostics. Analyzing the ice formation alone cannot diagnose an ice machine malfunction. However, when this analysis is used along with the “TXV Failure/Low Refrigerant Charge Symptoms” on page 66, it can help diagnose an ice machine malfunction.
Page 61
Extremely Thin at Evaporator Inlet There is no ice, or a considerable lack of ice formation at the inlet of the evaporator. Examples: The ice at the outlet of the evaporator reaches the correct thickness, but there is no ice formation at all at the inlet of the evaporator. Possible cause: Obstructed nozzles, Insufficient water flow, incorrect refrigerant charge.
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 70°F (21°C) ambient temperature and 50°F (10°C) water produces more ice than the same ice machine with 90°F (32°C) ambient and 70°F (21°C) water.
Page 63
If they match closely, determine if: • Another larger ice machine is required. • Relocating the existing equipment to lower the load conditions is required. Contact the local Manitowoc distributor for information on available options and accessories. Part Number STH111 Rev 01 08/23...
Mineral buildup can cause nozzle blockage, water tracking and an erratic ice fill pattern. Descale with Manitowoc Ice Machine cleaner to remove any mineral buildup before diagnosing the refrigeration system. 2. Install and insulate temperature leads: Digital thermometers with remote insulated thermocouples must be used to obtain temperatures.
STARVING TXV/LOW REFRIGERANT CHARGE SYMPTOMS • A starving TXV or low refrigerant charge will have a suction line temperature higher than normal and a discharge line temperature slightly higher than normal. • Low refrigerant charge will have both the suction and discharge line temperatures slightly higher than normal in the freeze and harvest cycles.
Suction and discharge line temperature will be low during the freeze cycle. Overcharge diagnosis can be difficult. USE0050 ice machines ship without access valves; Look for signs that an access valve has previously been added. When an overcharge is suspected remove the refrigerant and weigh in the correct refrigerant amount.
Component Check Procedures Main Fuse Function The control board fuse stops ice machine operation if electrical components fail causing high amp draw. Specifications • 250 Volt, 10 amp. Check Procedure 1. If the curtain light is on with the water curtain closed, the fuse is good.
Touch Pad Function User interface to select ice making, delay start or cleaning cycle and provides feedback on ice machine operation. Check For Normal Operation Action Normal Function Press and hold the control All Touch Pad lights turn on board test button for 3 seconds Press test button All Touch Pad lights turn off Press power button...
Page 71
Ohm Test Disconnect power from ice machine. Disconnect wire from control board and Ohm touch pad and interconnecting wire to verify correct operation. Pressing and depressing the touch pad must open and close the circuit. A switch that functions correctly will close as the button is pressed and open as the button is released.
Float Switch Function Open and close to indicate to the control board the level of water in the water trough. Specifications Normally closed, float operated magnetic reed switch. The float switch contacts are closed in the down position. When water raises the float to the up position the magnet in the float opens the contacts.
Page 73
Check Procedure Initial testing can be performed by viewing the control board light(s) while raising and lowering the float. The corresponding control board light must turn on and off when the float is raised (open contacts) and lowered (closed contacts). Ice Thickness or Harvest Float Switch: The light must be on in the down position.
Water Curtain Switch FUNCTION Movement of the water curtain controls bin switch operation. The bin switch has two main functions: 1. Harvest Cycle: When ice drops from the evaporator it passes through the water curtain and starts a harvest finish timer. This will allow additional individual cubes to harvest before entering back into the prechill cycle.
SPECIFICATIONS The bin switch is a magnetically operated reed switch. The magnet is attached to the lower right corner of the water curtain. The bin switch is connected to a varying D.C. voltage circuit. (Voltage does not remain constant.) NOTE: Because of a wide variation in D.C. voltage, it is not recommended that a voltmeter be used to check bin switch operation.
Bin Thermistor Function The bin thermistor stops the ice machine when the bin is full. The level of ice in the ice storage bin controls the ice machine shut-off. When the bin is full, ice cubes contact the bin thermistor, which cools down and signals the control board to stop the ice machine.
BIN THERMISTOR CHART Important If the ohmmeter reads “OL,” check the scale setting on the meter before assuming the thermistor is bad. Temperature of Thermistor Resistance K Ohms (x1000) °C °F Nominal 32.0 16.330 33.8 15.520 35.6 14.750 37.4 14.020 39.2 13.330 41.0...
Evaporator Thermistor Function Thermistor resistance values change with temperature. The value supplied to the control board is used to identify temperature at the thermistor location. Check Procedure Warning Disconnect electrical power to the entire ice machine before proceeding. 1. Disconnect thermistor from control board and measure resistance.
Important If the ohmmeter reads “OL,” check the scale setting on the meter before assuming the thermistor is bad. EVAPORATOR THERMISTOR CHART Temperature of Thermistor Resistance K Ohms (x1000) °C °F Nominal -13.0 65.240 -12.0 10.4 61.730 -11.0 12.2 58.429 -10.0 14.0 55.324...
Fan Cycle Control Function Cycles the fan motor on and off to maintain proper operating discharge pressure. The fan cycle control closes on an increase, and opens on a decrease in discharge pressure. Specifications Cut-In (Close) Cut-Out (Open) 140 psig 110 psig Check Procedure 1.
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 120°F/49°C) to ensure that the overload is closed and the resistance readings will be accurate.
Page 82
Compressor Drawing Locked Rotor The two likely causes of this are: • Defective starting component • Mechanically seized compressor To determine which you have: 1. Install high and low side gauge. 2. Try to start the compressor. 3. Watch the pressures closely. •...
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 off- the-shelf drier is in filtration. A Manitowoc drier has dirt-retaining filtration, with fiberglass filters on both the inlet and outlet ends.
Refrigerant Procedures REFRIGERANT PURGING PROCEDURE 1. Disconnect all electric power to the system and lockout tag out the power source(s). 2. Install piercing valves on the high and low side access fittings. 3. Attach manifold gauge set to the low and high side fittings.
Important The charge is critical on all Manitowoc ice machines. Use a scale to ensure the proper charge is installed. Quick disconnect fittings are required on the manifold gauge set to prevent refrigerant loss.
Page 86
NOTE: Manifold gauge set must be removed properly to ensure no refrigerant contamination or loss occurs. 14. Verify all of the vapor in the charging hoses is drawn into the refrigeration system before disconnecting the charging hoses. Run the ice machine in freeze cycle. Remove the high side low loss fitting.
System Contamination Cleanup This section describes the basic requirements for restoring contaminated systems to reliable service. 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.
Page 88
Contamination/Cleanup Chart Symptoms/Findings Required Cleanup Procedure No symptoms or suspicion of Normal evacuation/ contamination recharging procedure Moisture/Air Contamination symptoms Mild contamination Refrigeration system open to atmosphere cleanup procedure for longer than 15 minutes Refrigeration test kit and/or acid oil test shows contamination No burnout deposits in open compressor lines...
MILD SYSTEM CONTAMINATION CLEANUP 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.
SEVERE SYSTEM CONTAMINATION CLEANUP PROCEDURE 1. Remove the refrigerant charge. 2. Remove the compressor. 3. If burnout deposits are found, replace the TXV. 4. Wipe away any burnout deposits from suction and discharge lines at compressor. 5. Sweep through the open system with dry nitrogen. 6.
10. Charge the system with the proper refrigerant to the nameplate charge. 11. Operate the ice machine for one hour. Then, check the pressure drop across the suction line filter-drier. If the pressure drop is less than 2 psig, the filter- drier should be adequate for complete cleanup.
Page 92
THIS PAGE INTENTIONALLY LEFT BLANK Part Number STH111 Rev 01 08/23...
Charts Cycle Times, 24 Hr. Ice Production and Refrigerant Temperature Charts These charts are used as guidelines to verify correct ice machine operation. • Accurate collection of data is essential to obtain the correct diagnosis. Eliminate all non refrigeration problems before diagnosing the refrigeration system. •...
USE0050A AIR COOLED NOTE: These characteristics may vary depending on operating conditions. Cycle Times Freeze Time + Harvest Time = Total Cycle Time Air Temp. Freeze Time Harvest Entering Water Temperature °F/°C Time Condenser 50/10 70/21 90/32 °F/°C 70°/21° 43-46 46-48 48-52 80°/27°...
Need help?
Do you have a question about the USE0050 and is the answer not in the manual?
Questions and answers