Manitowoc MD0420A Technician's Handbook
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Manitowoc MD0420A Technician's Handbook

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Manitowoc
M series
Ice Machines
Technician's
Handbook
This manual is updated as new information and models are
released. Visit our website for the latest manual. www.welbilt.cn
Part Number 040005626 5/17

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Summary of Contents for Manitowoc MD0420A

  • Page 1 Manitowoc M series Ice Machines Technician’s Handbook This manual is updated as new information and models are released. Visit our website for the latest manual. www.welbilt.cn Part Number 040005626 5/17...

  • Page 3: Safety Notices

    Safety Notices As you work on Manitowoc equipment, 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 equipment. Throughout this handbook, you will see the following...
  • Page 4 Procedural Notices As you work on Manitowoc equipment, be sure to read the procedural notices in this handbook. These notices supply helpful information which may assist you as you work. Throughout this handbook, you will see the following types of procedural notices:...
  • Page 5 Warning Do not use electrical appliances or accessories other than those supplied by Manitowoc for your ice machine model. Warning Two or more people or a lifting device are required to lift this appliance.
  • Page 6 Warning This equipment contains high voltage electricity and refrigerant charge. Installation and repairs are to be performed by properly trained technicians aware of the dangers of dealing with high voltage electricity and refrigerant under pressure.The technician must also be certified in proper refrigerant handling and servicing procedures.
  • Page 7 Warning Do not obstruct machine vents or openings. Warning Do not store gasoline or other flammable vapors or liquids in the vicinity of this or any other appliance. Warning Do not clean with water jet. Warning It is the responsibility of the equipment owner to perform a Personal Protective Equipment Hazard Assessment to ensure adequate protection during maintenance procedures.
  • Page 8 Warning When using electric appliances, basic precautions must always be followed, including the following: a. Read all the instructions before using the appliance. b. To reduce the risk of injury, close supervision is necessary when an appliance is used near children. c.

  • Page 9: Table Of Contents

    Table of Contents GENERAL INFORMATION Model Numbers ..... 13 How to Read a Model Number ..14 Ice Machine Warranty Information .
  • Page 10 OPERATION Ice Making Sequence of Operation ..41 Control Board Timers ... . 42 Safety Limits ....43 Energized Parts Chart .
  • Page 11 COMPONENT CHECK PROCEDURES Main Fuse ......87 Bin Switch ......88 Float Switch .
  • Page 12 DIAGRAMS Wiring Diagrams ....127 Wiring Diagram Legend ... 127 M0420,M0500, M0700, M1000 1 PH Self- contained Air/Water-cooled .

  • Page 13: General Information

    General Information Model Numbers This manual covers the following models: Self-Contained Self-Contained Remote Air-Cooled Water-Cooled MD0420A ---- ---- MY0420A ---- ---- MD0500A MD0500W ---- MY0500A ---- ---- MD0700A MD0600W ---- MY0700A ---- ---- MD1000A MD1000W ---- MY1000A MY1000W ---- MD1400A...

  • Page 14: How To Read A Model Number

    How to Read a Model Number Cube Size Model Condenser Series Type M D 0500 A E E - WRAS 50Hz R - Regular A - Air-cooled D - Dice W - Water-cooled Y - Half-dice Warning An ice machine contains high voltage electricity and refrigerant charge.

  • Page 15: Ice Machine Warranty Information

    Ice Machine Warranty Information Owner Warranty Registration Card General Warranty coverage begins the day the ice machine is installed. Important Complete and mail the OWNER WARRANTY- REGISTRATION CARD as soon as possible to validate the installation date. If the OWNER WARRANTY REGISTRATION CARD is not returned, we will use the date of sale to the Distributor as the first day of warranty coverage for your new ice machine.
  • Page 16 Time and hourly rate schedules, as published from time to time by the COMPANY, apply to all service procedures. Additional expenses including without limitation, travel time, overtime premium, material cost, accessing or removal of the ice machine, or shipping are the responsibility of the owner, along with all maintenance, adjustments, cleaning, and ice purchases.
  • Page 17 To secure prompt and continuing warranty service, the warranty registration card must be completed and sent to the COMPANY within five (5) days from the installation date. Authorized Warranty Service To comply with the provisions of the warranty, a refrigeration service company qualified and authorized by your M series distributor, or a Factory Authorized Servicer must perform the warranty repair.

  • Page 18: Residential Warranty Coverage

    RESIDENTIAL WARRANTY COVERAGE WHAT DOES THIS LIMITED WARRANTY COVER? Subject to the exclusions and limitations below, Welbilt warrants to the original consumer that any new ice machine manufactured by Welbilt (the “Product”) shall be free of defects in material or workmanship for the warranty period outlined below under normal use and maintenance, and upon proper installation and start- up in accordance with the instruction manual supplied...
  • Page 19 To obtain warranty service or information regarding your M series product, please contact: WELBILT 2110 So. 26th St. P.O. Box 1720, Manitowoc, WI 54221-1720 Telephone: 920-682-0161 Fax: 920-683-7585 WHAT IS NOT COVERED? This limited warranty does not cover, and you are...
  • Page 20 In No Event Shall Welbilt Or Any Of Its Affiliates Be Liable To The Consumer Or Any Other Person For Any Incidental, Consequential Or Special Damages Of Any Kind (Including, Without Limitation, Loss Profits, Revenue Or Business) Arising From Or In Any Manner Connected With The Product, Any Breach Of This Limited Warranty, Or Any Other Cause Whatsoever, Whether Based On Contract, Tort Or Any Other...

  • Page 21: Installation

    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.

  • Page 22: Ice Machine Clearance Requirements

    Ice Machine Clearance Requirements Clearance Requirements Warning Do not obstruct ice machine vents or openings M0420 M0500 -M0700 Self-Contained Water-Cooled M1000 - Air-Cooled and Remote* M1400 Top/Sides 8" (20.3 cm) 8" (20.3 cm) Back 5" (12.7 cm) 5" (12.7 cm) *There is no minimum clearance required for water-cooled or remote ice machines.

  • Page 23: Ice Machine Heat Of Rejection

    Ice Machine Heat of Rejection Heat of Rejection Series Ice Machine Peak Conditioning M0420 5400 6300 M0500 5300 6100 M0700 9000 13900 M1000 16250 18600 M1400 28300 34300 1 B.T.U./Hour 2 Because the heat of rejection varies during the ice making cycle, the figure shown is an average.

  • Page 24: Electrical Requirements

    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. Total Circuit Ampacity The total circuit ampacity is used to help select the wire size of the electrical supply.

  • Page 25: Water Service/Drains

    (Check valves on sink faucets, dishwashers, etc.) • If water pressure exceeds the maximum recommended pressure, 80 psig (5.5 bar) obtain a water pressure regulator from your Manitowoc distributor. • Install a water shut-off valve for ice making potable water.

  • Page 26: Drain Connections

    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 27 WATER SUPPLY AND DRAIN LINE SIZING/ CONNECTIONS Part Number 040005626 5/17...
  • Page 28 This Page Intentionally Left Blank Part Number 040005626 5/17...

  • Page 29: Maintenance

    The ice machine must be taken apart for cleaning and sanitizing. ! Caution Use only Manitowoc approved Ice Machine Cleaner (part number 94-0546-3) Sanitizer (part number 94-0565-3). It is a violation of Federal law to use these solutions in a manner inconsistent with their labeling.

  • Page 30: Toggle Switch Operation

    TOGGLE SWITCH OPERATION Moving the toggle switch to clean will start a Clean cycle. • Setting the ice machine to stop after the clean cycle: Place the toggle switch in the clean position. The ice machine will stop after the clean cycle.
  • Page 31 ! Caution Do not mix Ice Machine Cleaner and Sanitizer solutions together. It is a violation of Federal law to use these solutions in a manner inconsistent with their labeling. Step 3 To start a cleaning cycle, move the toggle switch to Clean.
  • Page 32 Step 6 Mix a solution of cleaner and lukewarm water. Depending on the amount of mineral buildup, a larger quantity of solution may be required. Use the ratio in the table below to mix enough solution to thoroughly clean all parts. Solution Type Water Mixed with...
  • Page 33 Step 9 Mix a solution of sanitizer and warm water. Solution Type Water Mixed With Sanitizer 3 gal. (12 l) 2 oz (60 ml) sanitizer Step 10 Use half of the sanitizer/water solution to sanitize all removed components. Use a spray bottle to liberally apply the solution to all surfaces of the removed parts or soak the removed parts in the sanitizer/water solution.

  • Page 34: Remove Parts For Cleaning

    REMOVE PARTS FOR CLEANING Warning Disconnect electric power to the ice machine at the electric switch box before proceeding. 1. Remove the water curtain • Gently flex the curtain in the center and remove it from the right side. • Slide the left pin out.
  • Page 35 5. Remove the Water Trough • Depress tabs on right and left side of the water trough. • Allow front of water trough to drop as you pull forward to disengage the rear pins. • Remove the water trough from the bin area. Part Number 040005626 5/17...

  • Page 36: Preventative Maintenance Cleaning

    Preventative Maintenance Cleaning This cleaning procedure can be performed between the bi-annual cleaning and sanitizing cycles. This procedure does not require removing the ice from the bin. Step 1 Place the toggle switch in the off position after ice falls from the evaporator at the end of a Harvest cycle.

  • Page 37: Ice Machine Inspection

    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. There must be adequate airflow through and around the ice machine to maximize ice production and ensure long component life.

  • Page 38: Cleaning The Condenser

    Cleaning the Condenser General Warning Disconnect electric power to the ice machine head section and the remote condensing unit at the electric service switches before cleaning the condenser. A dirty condenser restricts airflow, resulting in excessively high operating temperatures. This reduces ice production and shortens component life.

  • Page 39: Removal From Service/Winterization

    Removal from Service/Winterization AIR-COOLED MODELS 1. Clean and sanitize the ice machine. 2. Place the toggle switch in the off position to turn off the ice machine. 3. Turn off the water supply, disconnect and drain the incoming ice-making water line at the rear of the ice machine and drain the water trough.
  • Page 40 This Page Intentionally Left Blank Part Number 040005626 5/17...

  • Page 41: Ice Making Sequence Of Operation

    Operation Ice Making Sequence of Operation NOTE: The toggle switch must be in the ON position and the water curtain must be closed before the ice machine will start. Water Purge Cycle The ice machine purges any remaining water from the water trough down the drain.

  • Page 42: Control Board Timers

    CONTROL BOARD TIMERS • The ice machine is locked into the freeze cycle for 6 minutes before a harvest cycle can be initiated. The freeze time lock in feature is bypassed on the initial cycle (manual start or after a full bin/safety limit condition).

  • Page 43: Safety Limits

    SAFETY LIMITS Safety limits are stored and indicated by the control board. The number of cycles required to stop the ice machine varies for each safety limit. Safety limits can be reset by cycling the toggle switch Off/On and starting a new ice making cycle. A safety limit is indicated by a flashing light on the control board.
  • Page 44 Safety Limit 3 If the harvest float switch hasn’t opened for 10 continuous seconds within 4 minutes of the water inlet valve energizing the ice machine stops. • Safety Limit 3 is bypassed on the initial cycle (manual start or after a full bin/safety limit condition).

  • Page 45: Energized Parts Chart

    Part Number 040005626 5/17...
  • Page 46 Part Number 040005626 5/17...

  • Page 47: Operational Checks

    Operational Checks ICE THICKNESS CHECK After a harvest cycle, inspect the ice cubes in the ice storage bin. The ice bridge connects the ice cubes and must be set to maintain an ice bridge thickness of 1/8" (3.2 mm). To adjust the thickness of the bridge refer to ice thickness adjustment.
  • Page 48 This Page Intentionally Left Blank Part Number 040005626 5/17...

  • Page 49: Troubleshooting

    Troubleshooting 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 move the toggle switch to off, then press and hold the test button on the control board for 3 seconds.

  • Page 50: Diagnosing An Ice Machine That Will Not Run

    Diagnosing an Ice Machine that Will Not Run Warning High (line) voltage is applied to the control board at all times. Removing the control board fuse or cycling the toggle switch Off/On will not remove the power supplied to the control board. 1.

  • Page 51: Ice Machine Does Not Cycle Into Harvest When Water Loses Contact With The Harvest Float Switch

    Ice Machine Does Not Cycle Into Harvest when Water Loses Contact with the Harvest Float Switch NOTE: The ice machine will make a thick or double slab when a new freeze cycle is started with ice already present on the evaporator. Two of the most common scenarios are: •...
  • Page 52 Step 1 Disconnect power to the ice machine, remove the electrical panel to allow viewing of the control board lights. Disconnect the harvest float switch wire from the control board and place a jumper on the control board harvest switch terminals. Step 2 Bypass the freeze time lock-in feature by moving the toggle switch Off/On to cycle the ice machine on.

  • Page 53: Ice Machine Cycles Into Harvest Before Water Loses Contact With The Harvest Float Switch

    Ice Machine Cycles Into Harvest Before Water loses Contact with the Harvest Float Switch Step 1 Disconnect power to the ice machine, remove the electrical panel to allow viewing of the control board lights and disconnect the harvest float switch from the control board.

  • Page 54: Ice Production Check

    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 55: Installation/Visual Inspection Checklist

    Installation/Visual Inspection Checklist Ice machine is not level • Level the ice machine Condenser is dirty • Clean the condenser Water filtration is plugged (if used) • Install a new water filter Water drains are not run separately and/or are not vented •...

  • Page 56: Water System Checklist

    Water System Checklist A water-related problem often causes the same symptoms as a refrigeration system component malfunction. Example: A water dump valve leaking during the freeze cycle, a system low on charge, and a starving TXV have similar symptoms. Water system problems must be identified and eliminated prior to replacing refrigeration components.

  • Page 57: Ice Formation Pattern

    Ice Formation Pattern Evaporator ice formation pattern analysis is helpful in ice machine diagnostics. Analyzing the ice formation pattern alone cannot diagnose an ice machine malfunction. However, when this analysis is used along with the Refrigeration System Operational Analysis Table, it can help diagnose an ice machine malfunction.
  • Page 58 Extremely Thin at Evaporator Outlet There is no ice, or a considerable lack of ice formation on the outlet of the evaporator. Examples: No ice at all at the outlet of the evaporator, but ice forms at the inlet half of the evaporator. Or, the ice at the outlet of the evaporator reaches the correct thickness, but the outlet of the evaporator already has 1/2"...
  • Page 59 Evaporator Tubing Routing Routing of the tubing on the back of the evaporator determines the ice fill pattern failure mode. One Evaporator, One TXV Models The evaporator outlet tubing does not exit directly at the top of the evaporator, but exits several inches below the top of the evaporator.

  • Page 60: Safety Limits

    SAFETY LIMITS Safety limits are stored and indicated by the control board. The number of cycles required to stop the ice machine varies for each safety limit. Safety limits can be reset by cycling the toggle switch Off/On and starting a new ice making cycle. A safety limit is indicated by a flashing light on the control board.
  • Page 61 Safety Limit 3 If the harvest float switch hasn’t opened for 10 continuous seconds within 4 minutes of the water inlet valve energizing the ice machine stops. • Safety Limit 3 is bypassed on the initial cycle (manual start or after a full bin/safety limit condition).
  • Page 62 Determining Which Safety Limit Stopped the Ice Machine: 1. Cycle the toggle switch Off. 2. Cycle the toggle switch On to start ice making. 3. Watch the safety limit lights. • One will flash corresponding to safety limits 1 or 2. 4.
  • Page 63 Safety Limit Checklist The following checklists are designed to assist the service technician in analysis. However, because there are many possible external problems, do not limit your diagnosis to only the items listed. Safety Limit #1 Freeze time exceeds 60 minutes for 3 consecutive freeze cycles.
  • Page 64 Refrigeration System • Non- OEM components • Improper refrigerant charge • Defective compressor • TXV starving or flooding (check bulb mounting) • Non-condensible in refrigeration system • Plugged or restricted high side refrigerant lines or component • Defective harvest valve Part Number 040005626 5/17...
  • Page 65 Safety Limit #2 Harvest time exceeds 3.5 minutes for 100 Consecutive harvest cycles. Possible Cause Checklist Improper installation • Refer to “Installation/Visual Inspection Checklist” on page 55. Water System • Water area (evaporator) dirty • Dirty/defective water dump valve • Vent tube not installed on water outlet drain •...
  • Page 66 Safety Limit 3 The harvest float switch hasn’t opened for 10 continuous seconds within 4 minutes of the water inlet valve energizing. Possible Cause Checklist Improper installation • Refer to “Installation/Visual Inspection Checklist” on page 55. Water System • Water dump valve •...

  • Page 67: Analyzing Discharge Pressure

    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 Hr. Ice Production and Refrigerant Pressure Charts” on page 117 for ice machine being checked.
  • Page 68 Discharge Pressure High Checklist Improper Installation • Refer to “Installation/Visual Inspection Checklist” on page 55. Condenser Air Flow • High inlet air temperature • Condenser discharge air re-circulation • Dirty condenser fins • Defective fan cycling control • Defective fan motor Improper Refrigerant Charge •...

  • Page 69: Analyzing Suction Pressure

    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.
  • Page 70 Procedure Step 1. Determine the ice machine operating conditions. Example: Air temp. entering condenser: 90°F/32.2°C Air temp. around ice machine: 80°F/26.7°C Water temp. entering water fill valve: 70°F/21.1°C 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.
  • Page 71 Suction Pressure High Checklist Improper Installation • Refer to “Installation/Visual Inspection Checklist” on page 55. Discharge Pressure • Discharge pressure is too high, and is affecting suction pressure, refer to “Discharge Pressure High Checklist” on page 68. Improper Refrigerant Charge •...
  • Page 72 Suction Pressure Low Checklist Improper Installation • Refer to “Installation/Visual Inspection Checklist” on page 55. Discharge Pressure • Discharge pressure is too low, and is affecting suction pressure, refer to “Freeze Cycle Discharge Pressure Low Checklist” Improper Refrigerant Charge • Undercharged •...

  • Page 73: Harvest Valve

    Harvest Valve General The harvest valve is an electrically operated valve that opens when energized, and closes when de-energized. 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 discharge line and the evaporator and performs two functions: 1.
  • Page 74 Harvest 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 circuit board has initiated a harvest cycle, the evaporator temperature remains unchanged from the freeze cycle.
  • Page 75 Use the following procedure and table to help determine if a harvest valve is remaining partially open during the freeze cycle. 1. Wait five minutes into the freeze cycle. 2. Feel the inlet of the harvest valve(s). Important Feeling the harvest valve outlet or across the harvest valve itself will not work for this comparison.
  • Page 76 Findings Comments The inlet of the harvest This is normal as the valve is cool enough to discharge line should touch and the compressor always be too hot to touch discharge line is hot. and the harvest valve inlet, although too hot to touch Cool &...

  • Page 77: Comparing Evaporator Inlet/Outlet Temperatures

    Comparing Evaporator Inlet/Outlet Temperatures The temperatures of the suction lines entering and leaving the evaporator alone cannot diagnose an ice machine. However, comparing these temperatures during the freeze cycle, along with the Refrigeration System Operational Analysis Table, can help diagnose an ice machine malfunction.

  • Page 78: Discharge Line Temperature Analysis

    Discharge Line Temperature Analysis GENERAL Knowing if the discharge line temperature is increasing, decreasing or remaining constant can be an important diagnostic tool. Maximum 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.
  • Page 79 Discharge Line Temperature Above 150°F (66°C) at End of Freeze Cycle: Ice machines that are operating normally will have consistent maximum discharge line temperatures above 150°F (66°C). Verify the expansion valve sensing bulb is positioned and secured correctly. Discharge Line Temperature Below 150°F (66°C) at End of Freeze Cycle Ice machines that have a flooding expansion valve will have a maximum discharge line temperature that...

  • Page 80: Refrigeration Component Diagnostics

    Refrigeration Component Diagnostics All electrical and water related problems must be corrected before these charts will work properly. These tables must be used with charts, checklists and other references to eliminate refrigeration components not listed and external items and problems that will cause good refrigeration components to appear defective.
  • Page 81 PROCEDURE Step 1 Complete each item individually in the “Operational Analysis” column. Enter check marks ( ) in the boxes. Each time the actual findings of an item in the “Operational Analysis” column matches the published findings on the table, enter a check mark. Example: Freeze cycle suction pressure is determined to be low.

  • Page 82: Final Analysis

    FINAL ANALYSIS The column with the highest number of check marks identifies the refrigeration problem. Column 1 – Harvest Valve Leaking A leaking harvest valve must be replaced. Column 2 – Low Charge/TXV Starving Normally, a starving expansion valve only affects the freeze cycle pressures, not the harvest cycle pressures.

  • Page 83: Refrigeration Component Diagnostic Chart

    Refrigeration Component Diagnostic Chart Part Number 040005626 5/17...
  • Page 84 Part Number 040005626 5/17...
  • Page 85 Part Number 040005626 5/17...
  • Page 86 This Page Intentionally Left Blank Part Number 040005626 5/17...

  • Page 87: Component Check Procedures

    Component Check Procedures Main Fuse Function The control board fuse stops ice machine operation if electrical components fail causing high amp draw. Specifications • The main fuse is 250 Volt, 3.15 amp. Warning High (line) voltage is applied to the control board at all times.

  • Page 88: Bin Switch

    Bin Switch Function Bin switch operation is controlled by the movement of the water curtain. The bin switch has two main functions: 1. Terminating the harvest cycle and returning the ice machine to the freeze cycle. This occurs when the bin switch is opened and closed again within 30 seconds of opening during the harvest cycle.
  • Page 89 Ohm Test 1. Disconnect the bin switch wires from the control board. 2. Connect an ohmmeter to the disconnected bin switch. 3. Cycle the bin switch open and closed numerous times by opening and closing the water curtain. NOTE: To prevent misdiagnosis: •...

  • Page 90: Float Switch

    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 91 If the control board light does not respond to the float proceed with step 1 below. 1. Disconnect power to the ice machine and pull the float switch and connector through the ice machine base and disconnect. 2. Attach an ohm meter lead to each float switch wire.

  • Page 92: Compressor Electrical Diagnostics

    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 93 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. •...

  • Page 94: Fan Cycle Control

    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 Cut-Out (Close) (Open) 335 psig ±5 275 psig ±5 Check Procedure Disconnect electrical power to the ice machine at the...

  • Page 95: High Pressure Cutout (Hpco) Control

    High Pressure Cutout (HPCO) Control Function Stops the ice machine if subjected to excessive high- side pressure. The HPCO control is normally closed, and opens on a rise in discharge pressure. Specifications 600 psig ±10 Cut-out: 450 psig ±10 Cut-in: (Must be below 450 psig to reset).

  • Page 96: Refrigeration Components

    Refrigeration Components HEAD PRESSURE CONTROL VALVE Manitowoc remote systems require head pressure control valves with special settings. Replace defective head pressure control valves only with “original” Manitowoc replacement parts. Refrigerant Charge Verification The correct amount of refrigerant (name plate charge) is required to operate correctly at all ambient conditions.

  • Page 97: Harvest Cycle Operation

    Freeze Cycle Operation All Models The head pressure control valve is non adjustable. At ambient temperatures of approximately 70°F (21°C) or above, refrigerant flows through the valve from the condenser to the receiver inlet. At temperatures below this (or at higher temperatures if it is raining), the head pressure control dome’s nitrogen charge closes the condenser port and opens the bypass port from the compressor discharge line.
  • Page 98 NOTE: A head pressure control valve that will not bypass, will function properly with condenser air temperatures of approximately 70°F (21°C) or above. When the temperature drops below 70°F (21°C), the head pressure control valve fails to bypass and the ice machine malfunctions.
  • Page 99 Harvest Cycle REMOTE CONDENSER The head pressure control cycles into full bypass due to the pressure drop when the harvest valve opens. Refrigerant flows from the compressor to the evaporator through the harvest valve and the head pressure valve is out of the circuit. Undercharge Symptoms •...

  • Page 100: Harvest Pressure Regulating (Hpr) System Remote Condenser Only

    HARVEST PRESSURE REGULATING (HPR) SYSTEM REMOTE CONDENSER ONLY GENERAL The harvest pressure regulating (HPR) system includes: • Harvest pressure regulating solenoid valve (HPR solenoid). This is an electrically operated valve which opens when energized, and closes when de-energized. INLET OUTLET FLOW HPR SOLENOID •...
  • Page 101 FREEZE CYCLE The HPR system is not used during the freeze cycle. The HPR solenoid is closed (de-energized), preventing refrigerant flow into the HPR valve. HARVEST CYCLE During the harvest cycle, the check valve in the discharge line prevents refrigerant in the remote condenser and receiver from back feeding into the evaporator and condensing to liquid.
  • Page 102 4. Harvest time is longer than normal and control board indicates safety limit #2? (Refer to Cycle Times/Refrigerant Pressures/24 Hour Ice Production Charts). 5. Discharge line temperature is greater than 160°F at the end of the freeze cycle? (See Discharge Line Temperature Analysis) 6.

  • Page 103: Water Regulating Valve

    WATER REGULATING VALVE Water-Cooled Models Only FUNCTION The water regulating valve maintains the freeze cycle discharge pressure. CHECK PROCEDURE 1. Determine if the head pressure is high or low (refer to cycle time/24 hour ice production and operational pressure chart for the model you are servicing).

  • Page 104: Refrigerant Recovery/Evacuation

    Refrigerant Recovery/Evacuation DEFINITIONS Recover To remove refrigerant, in any condition, from a system and store it in an external container, without necessarily testing or processing it in any way. Recycle To clean refrigerant for re-use by oil separation and single or multiple passes through devices, such as replaceable core filter-driers, which reduce moisture, acidity and particulate matter.

  • Page 105: Refrigerant Re-Use Policy

    REFRIGERANT RE-USE POLICY Manitowoc recognizes and supports the need for proper handling, re-use, and disposal of refrigerants. Manitowoc service procedures require recapturing refrigerants, not venting them to the atmosphere. It is not necessary, in or out of warranty, to reduce or compromise the quality and reliability of your customers’...
  • Page 106 Compressor motor burnouts and improper past service prevent refrigerant re-use. • Refer to “System Contamination Cleanup” on page 110 to test for contamination. 5. “Substitute” or “Alternative” Refrigerant • Must use only Manitowoc-approved alternative refrigerants. • Must follow Manitowoc-published conversion procedures. Part Number 040005626 5/17...

  • Page 107: Recovery And Recharging Procedures

    Do not purge refrigerant to the atmosphere. Capture refrigerant using recovery equipment. Follow the manufacturer’s recommendations. Important Manitowoc 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.
  • Page 108 SELF-CONTAINED RECOVERY/EVACUATION 1. Cycle the toggle switch Off. 1. Install manifold gauge set and recovery unit or two-stage vacuum pump. 2. 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.
  • Page 109 CHARGING PROCEDURES Important The charge is critical on all Manitowoc machines. Use a scale or a charging cylinder to ensure the proper charge is installed. 1. Cycle the toggle switch Off. 2. Close the vacuum pump valve, the low side manifold gauge valve.

  • Page 110: System Contamination Cleanup

    This section describes the basic requirements for restoring contaminated systems to reliable service. Important Manitowoc 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.
  • Page 111 Contamination/Cleanup Chart Required Symptoms/Findings Cleanup Procedure No symptoms or suspicion of Normal contamination evacuation/ recharging procedure Moisture/Air Contamination symptoms Mild Refrigeration system open to contamination atmosphere for longer than 15 minutes cleanup Refrigeration test kit and/or acid oil test procedure shows contamination No burnout deposits in open compressor lines...

  • Page 112: Mild System Contamination Cleanup Procedure

    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.

  • Page 113: Severe System Contamination Cleanup Procedure

    SEVERE SYSTEM CONTAMINATION CLEANUP PROCEDURE 1. Remove the refrigerant charge. 2. Remove the compressor. 3. Disassemble the harvest solenoid valve. If burnout deposits are found inside the valve, install a rebuild kit, and replace the TXV and head pressure control valve. 4.

  • Page 114: Replacing Pressure Controls Without Removing Refrigerant Charge

    REPLACING PRESSURE CONTROLS WITHOUT REMOVING REFRIGERANT CHARGE This procedure reduces repair time and cost. Use it when any of the following components require replacement, and the refrigeration system is operational and leak-free. • Fan cycle control • High pressure cut-out control •...
  • Page 115 FIG. A - “PINCHING OFF” TUBING FIG. B - RE-ROUNDING TUBING SV1406 Using Pinch Off Tool Part Number 040005626 5/17...

  • Page 116: Refrigerant Amount

    Refrigerant Amount NOTE: All models charged with R410A refrigerant. Model Air-Cooled Water-Cooled M420 50 Hz 16oz 14oz M500 50 Hz 18oz 14oz M700 50 Hz 24oz 18oz M1000 50Hz 44oz 24oz M1400 50Hz 42oz 24oz Part Number 040005626 5/17...

  • Page 117: Cycle Times, 24 Hr. Ice Production And Refrigerant Pressure Charts

    Charts Cycle Times, 24 Hr. 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. • Production and cycle times are for dice cube - Half dice cube cycle times can be 1-2 minutes faster depending on model and ambient temperature.

  • Page 118: M0420A Self-Contained Air-Cooled

    M0420A SELF-CONTAINED AIR-COOLED NOTE: These characteristics may vary depending on operating conditions. Cycle Times Freeze Time + Harvest Time = Total Cycle Time Freeze Time Air Temp. Entering Harvest Water Temperature °F/°C Condenser Time °F/°C 50/10 70/21 90/32 70/21 11.7-13.7 12.5-14.5 13.6-15.8 80/27...

  • Page 119: M0500A Self-Contained Air-Cooled

    M0500A SELF-CONTAINED AIR-COOLED NOTE: These characteristics may vary depending on operating conditions. Cycle Times Freeze Time + Harvest Time = Total Cycle Time Freeze Time Air Temp. Entering Harvest Water Temperature °F/°C Condenser Time °F/°C 50/10 70/21 90/32 70/21 11.9-13.6 14.1-16.1 15.7-17.9 80/27...

  • Page 120: M0500W Self-Contained Water-Cooled

    M0500W SELF-CONTAINED WATER-COOLED NOTE: These characteristics may vary depending on operating conditions. Cycle Times Freeze Time + Harvest Time = Total Cycle Time Freeze Time Air Temp. Around Ice Harvest Water Temperature °F/°C Machine Time °F/°C 50/10 70/21 90/32 70/21 10.7-13.7 13.6-15.5 15.7-17.7...

  • Page 121: M0700A Self-Contained Air-Cooled

    M0700A SELF-CONTAINED AIR-COOLED NOTE: These characteristics may vary depending on operating conditions. Cycle Times Freeze Time + Harvest Time = Total Cycle Time Freeze Time Air Temp. Entering Harvest Water Temperature °F/°C Condenser Time °F/°C 50/10 70/21 90/32 70/21 8.5-11.0 11.5-13.2 12.4-14.3 80/27...

  • Page 122: M0700W Self-Contained Water-Cooled

    M0700W SELF-CONTAINED WATER-COOLED NOTE: These characteristics may vary depending on operating conditions. Cycle Times Freeze Time + Harvest Time = Total Cycle Time Freeze Time Air Temp. Around Ice Harvest Water Temperature °F/°C Machine Time °F/°C 50/10 70/21 90/32 70/21 9.5-11.0 10.9-12.5 11.5-13.2...

  • Page 123: M1000A Self-Contained Air-Cooled

    M1000A SELF-CONTAINED AIR-COOLED NOTE: These characteristics may vary depending on operating conditions. Cycle Times Freeze Time + Harvest Time = Total Cycle Time Freeze Time Air Temp. Entering Harvest Water Temperature °F/°C Condenser Time °F/°C 50/10 70/21 90/32 70/21 8.5-10.1 9.9-11.7 11.6-12.6 80/27...

  • Page 124: M1000W Self-Contained Water-Cooled

    M1000W SELF-CONTAINED WATER-COOLED NOTE: These characteristics may vary depending on operating conditions. Cycle Times Freeze Time + Harvest Time = Total Cycle Time Freeze Time Air Temp. Around Ice Harvest Water Temperature °F/°C Machine Time °F/°C 50/10 70/21 90/32 70/21 8.3-9.8 8.8-10.4 9.7-11.5...

  • Page 125: M1400A Self-Contained Air-Cooled

    M1400A SELF-CONTAINED AIR-COOLED Preliminary Data, Subject to Change Characteristics vary depending on operating conditions. CYCLE TIMES Freeze Time + Harvest Time = Total Cycle Time Air Temp. Freeze Time Entering Harvest Water Temperature °F/°C Condenser Time °F/°C 50/10 70/21 90/32 70/21 9.4-10.8 10.4-11.8...
  • Page 126 This Page Intentionally Left Blank Part Number 040005626 5/17...

  • Page 127: Wiring Diagrams

    Diagrams Wiring Diagrams The following pages contain electrical wiring diagrams Be sure you are referring to the correct diagram for the ice machine you are servicing. Warning Always disconnect power before working on electrical circuitry. WIRING DIAGRAM LEGEND The following symbols are used on all of the wiring diagrams: Internal Compressor Overload (Some models have external compressor...

  • Page 128: M0420,M0500, M0700, M1000 1 Ph Self- Contained Air/Water-Cooled

    M0420,M0500, M0700, M1000 1 PH SELF- CONTAINED AIR/WATER-COOLED Part Number 040005626 5/17...

  • Page 129: Electronic Control Board

    ELECTRONIC CONTROL BOARD Part Number 040005626 5/17...

  • Page 130: Refrigeration Tubing Schematics

    Refrigeration Tubing Schematics SELF-CONTAINED AIR OR WATER-COOLED EVAPORATOR HEAT EXCHANGER EXPANSION VALVE HARVEST SOLENOID VALVE STRAINER DRIER AIR OR WATER RECEIVER CONDENSER COMPRESSOR (WATER COOLED ONLY) Part Number 040005626 5/17...
  • Page 132 Welbilt. No.151 Jianye Road, Binjiang District, © 2017 Manitowoc Hangzhou, China 310011 Part Number 040005626 5/17 Website – www.welbilt.cn...

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