Manitowoc S0850M Service Manual
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Manitowoc S0850M Service Manual

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S0850M
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Thank you for selecting a Manitowoc Ice Machine, the dependability leader in ice making equipment and related products.
With proper installation, care and maintenance, your new Manitowoc Ice Machine will provide you with many years of
reliable and economical performance.
Part Number 80-1558-3
4/2004

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Summary of Contents for Manitowoc S0850M

  • Page 1 Service Manual Thank you for selecting a Manitowoc Ice Machine, the dependability leader in ice making equipment and related products. With proper installation, care and maintenance, your new Manitowoc Ice Machine will provide you with many years of reliable and economical performance.

  • Page 2: Safety Notices

    Caution statement before proceeding, valuable care and maintenance information. If you and work carefully. encounter problems not covered by this manual, do not proceed, contact Manitowoc Ice, Inc. We will be happy to provide assistance. Important Routine adjustments and maintenance procedures outlined in this manual are not covered by the warranty.

  • Page 3: Table Of Contents

    Ice Machines ........
  • Page 4 Table of Contents (continued) Section 3 Ice Machine Operation Component Identification ......... Sequence Of Operation .
  • Page 5 Wiring Diagram Legend ........S0850M - Self Contained - 1 Phase ......
  • Page 6 Table of Contents (continued) Cycle Time/24 Hour Ice Production/Refrigerant Pressure Charts ..7-19 Refrigerant Recovery/Evacuation and Recharging ..... 7-20 Normal Self-Contained Model Procedures .

  • Page 7: General Information

    Section 1 General Information Section 1 General Information Model Numbers How to Read a Model Number This manual covers the following models: # CUBE SIZE CONDENSER TYPE Self-Contained DICE WATER-COOLED HALF-DICE WATER-COOLED Water-Cooled SD0853WM MARlNE MODEL SY0855WM NOTE: Model numbers ending in 3 indicate a 3-phase S Y 0855 W M unit.

  • Page 8: Accessories

    General Information Section 1 Accessories MANITOWOC CLEANER AND SANITIZER Manitowoc Ice Machine Cleaner and Sanitizer are Contact your Manitowoc distributor for these optional available in convenient 16 oz. (473 ml) bottles. These accessories: are the only cleaner and sanitizer approved for use with BIN CASTER Manitowoc products.

  • Page 9: Model/Serial Number Location

    These numbers are required when requesting The model and serial number are listed on the MODEL/ information from your local Manitowoc distributor, or SERIAL NUMBER DECAL affixed to the ice machine, Manitowoc Ice, Inc. remote condenser and storage bin. SV13147 MODEL/SERIAL PLATE...

  • Page 10: Owner Warranty Registration Card

    (3) years from the date of is not authorized to perform warranty service, contact original installation. your Manitowoc distributor or Manitowoc Ice, Inc. for the 2. The evaporator and compressor are covered by an name of the nearest authorized service representative.

  • Page 11: Installation Instructions

    These instructions are provided to assist the qualified Important installer. Check your local Yellow Pages for the name of the nearest Manitowoc distributor, or call Manitowoc Ice, Failure to follow these installation guidelines may Inc. for information regarding start-up services.

  • Page 12: Location Of Ice Machine

    Heat of Rejection following criteria. If any of these criteria are not met, Series Ice Machine select another location. Air Conditioning Peak S0850M 12,000 18,000 • The location must be free of airborne and other B.T.U./Hour contaminants. Because the heat of rejection varies during the ice making cycle, the figure shown is an average.

  • Page 13: Electrical Service

    Section 2 Installation Instructions Electrical Service FUSE/CIRCUIT BREAKER A separate fuse/circuit breaker must be provided for GENERAL each ice machine. Circuit breakers must be H.A.C.R. rated (does not apply in Canada). Warning MINIMUM CIRCUIT AMPACITY All wiring must conform to local, state and national codes.

  • Page 14: Self-Contained Electrical Wiring Connections

    Installation Instructions Section 2 Self-Contained Electrical Wiring Connections SELF CONTAINED ICE MACHINE Warning 208-230/3/60 These diagrams are not intended to show proper wire routing, wire sizing, disconnects, etc., only the correct wire connections. All electrical work, including wire routing and grounding, must conform to local, state and national electrical codes.

  • Page 15: Water Supply And Drain Requirements

    Section 2 Installation Instructions Water Supply and Drain Requirements DRAIN CONNECTIONS Follow these guidelines when installing drain lines to WATER SUPPLY prevent drain water from flowing back into the ice Local water conditions may require treatment of the machine and storage bin: water to inhibit scale formation, filter sediment, and •...

  • Page 16: Water Supply And Drain Line Sizing/Connections

    Installation Instructions Section 2 WATER SUPPLY AND DRAIN LINE SIZING/CONNECTIONS ! Caution Plumbing must conform to state and local codes. Tubing Size Up to Ice Location Water Temperature Water Pressure Ice Machine Fitting Machine Fitting 35°F (1.6°C) Min. 20 psi (137.9 kPA) Min. 3/8"...

  • Page 17: Installation Check List

    Section 2 Installation Instructions Installation Check List Are the ice machine and bin drains vented? Is the Ice Machine level? Are all electrical leads free from contact with refrigeration lines and moving equipment? Has all of the internal packing been removed? Has the owner/operator been instructed Have all of the electrical and water connections regarding maintenance and the use of...

  • Page 18: Before Starting The Ice Machine

    Installation Instructions Section 2 Before Starting the Ice Machine All Manitowoc ice machines are factory-operated and adjusted before shipment. Normally, new installations do not require any adjustment. To ensure proper operation, follow the Operational Checks in Section 3 of this manual. Starting the ice machine and completing the Operational Checks are the responsibilities of the owner/operator.

  • Page 19: Ice Machine Operation

    Section 3 Ice Machine Operation Section 3 Ice Machine Operation Component Identification Water Distribution Tube Toggle Switch Water Curtain Dump Valve Check Valve sv3149 Ice Thickness Probe Curtain Retainer Water Level Probe Water Inlet Location Water Pump Water Inlet Valve (Located in Refrigeration Compartment) sv3150 Part Number 80-1558-3...

  • Page 20: Sequence Of Operation

    Ice Machine Operation Section 3 Sequence Of Operation NOTE: The toggle switch must be in the ice position and FREEZE SEQUENCE the water curtain must be in place on the evaporator 3. Prechill before the ice machine will start. The compressor is on for 30 seconds (60 seconds initial INITIAL START-UP OR START-UP AFTER cycle) prior to water flow, to prechill the evaporator.

  • Page 21: Harvest Sequence

    Section 3 Ice Machine Operation HARVEST SEQUENCE AUTOMATIC SHUT-OFF 5. Water Purge 7. Automatic Shut-Off The harvest valve(s) opens at the beginning of the water When the storage bin is full at the end of a harvest purge to divert hot refrigerant gas into the evaporator. sequence, the sheet of cubes fails to clear the water curtain and will hold it open.

  • Page 22: Operational Checks

    The ice thickness probe is factory-set to maintain the ice GENERAL bridge thickness at 1/8" (.32 cm). Manitowoc ice machines are factory-operated and NOTE: Make sure the water curtain is in place when adjusted before shipment. Normally, new installations do performing this check.

  • Page 23: Harvest Sequence Water Purge

    Section 3 Ice Machine Operation HARVEST SEQUENCE WATER PURGE • During the harvest sequence water purge, the water fill valve energizes and de-energizes by time. The The harvest sequence water purge adjustment may be water purge must be at the factory setting of 45 used when the ice machine is hooked up to special seconds for the water fill valve to energize during the water systems, such as a de-ionized water treatment...
  • Page 24 Ice Machine Operation Section 3 THIS PAGE INTENTIONALLY LEFT BLANK Part Number 80-1558-3...

  • Page 25: Maintenance

    Section 4 Maintenance Section 4 Maintenance General Water-Cooled Condenser and Water Regulating Valve You are responsible for maintaining the ice machine in accordance with the instructions in this manual. Symptoms of restrictions in the condenser water circuit Maintenance procedures are not covered by the include: warranty.

  • Page 26: Guardian

    *Although one sachet is recommended, extreme conditions may 4. Sanitize the bin/dispenser. necessitate using two sachet packets. 5. Install a replacement sachet packet and reinstall all Guardian™ sachet packets are available through your panels. local Manitowoc ice machine dealer. Part Number 80-1558-3...

  • Page 27: Interior Cleaning And Sanitizing

    Step 3 Wait about two minutes or until water starts to flow over the evaporator. ! Caution Step 4 Add the proper amount of Manitowoc Ice Use only Manitowoc approved Ice Machine Cleaner Machine Cleaner to the water trough. (part number 94-0546-3) and Sanitizer (part number 94-0565-3).

  • Page 28: Sanitizing Procedure

    Maintenance Section 4 SANITIZING PROCEDURE Use sanitizer to remove algae or slime. Do not use it to Step 4 Use the sanitizing solution and a sponge or remove lime scale or other mineral deposits. cloth to sanitize (wipe) all parts and interior surfaces of the ice machine.

  • Page 29: Removal Of Parts For Cleaning/Sanitizing

    Section 4 Maintenance REMOVAL OF PARTS FOR CLEANING/SANITIZING 5. Use a soft-bristle brush or sponge (NOT a wire brush) to carefully clean the parts. 1. Turn off the electrical and water supply to the ice machine (and dispenser when applicable). ! Caution Do not mix Cleaner and Sanitizer solutions together.
  • Page 30 Maintenance Section 4 1. Water Curtain 2. Ice Thickness Probe A. Gently flex the curtain in the center and remove A. Compress the hinge pin on the top of the ice it from the right side. thickness probe. B. Slide the left pin out. STEP 1 STEP 2 COMPRESS...
  • Page 31 Section 4 Maintenance 3. Water Distribution Tube 4. Water Trough A. Depress tabs on right and left side of the water Warning trough. Removing the distribution tube while the water B. Allow front of water trough to drop as you pull pump is running will allow water to spray from ice forward to disengage the rear pins.
  • Page 32 Maintenance Section 4 Water Level Probe Water Pump 1. Remove the water trough. Warning Disconnect the electric power to the ice machine at Warning the electric service switch box and turn off the water Disconnect the electrical power to the ice machine supply before proceeding.
  • Page 33 Section 4 Maintenance Water Dump Valve Important The water dump valve normally does not require The plunger and the inside of the enclosing tube removal for cleaning. To determine if removal is must be completely dry before assembly. necessary: 1. Locate the water dump valve. NOTE: During cleaning, do not stretch, damage or 2.
  • Page 34 Maintenance Section 4 Evaporator Tray Removal Drain Line Check Valve 1. Remove the water trough. The drain line check valve normally does not require removal for cleaning. Water loss from the sump trough 2. Remove thumbscrew on left side of tray. will indicate removal and cleaning are required.

  • Page 35: Removing The Front Panels

    Section 4 Maintenance Water Inlet Valve Removing the Front Panel The water inlet valve normally does not require removal 1. Disconnect power to ice machine. for cleaning. Refer to Section 5 for a list of causes for 2. Loosen thumbscrews. Do not remove they are “No Water Entering Water Trough”...

  • Page 36: Removal From Service/Winterization

    Maintenance Section 4 Removal from Service/Winterization WATER-COOLED ICE MACHINES 1. Perform steps 1-6 under “Self-Contained Air-Cooled GENERAL Ice Machines.” Special precautions must be taken if the ice machine is 2. Disconnect the incoming water and drain lines from to be removed from service for an extended period of the water-cooled condenser.

  • Page 37: Before Calling For Service

    Section 5 Before Calling For Service Section 5 Before Calling For Service Checklist If a problem arises during operation of your ice machine, follow the checklist below before calling service. Routine adjustments and maintenance procedures are not covered by the warranty. Problem Possible Cause To Correct...

  • Page 38: Safety Limit Feature

    In addition to the standard safety controls, such as the A. If the safety limit feature has stopped the ice high pressure cutout, your Manitowoc ice machine machine, it will restart after a short delay. features built-in safety limits which will stop the ice Proceed to step 2.

  • Page 39: Electrical System

    Section 6 Electrical System Section 6 Electrical System Energized Parts Charts SELF-CONTAINED WATER-COOLED MODELS Control Board Relays Contactor Ice Making Length Sequence Of Harvest Harvest Water Cond. Of Time Water Dump Contactor Operation Valve Valve Not Used Inlet Comp. Pump Valve Coil (Left)

  • Page 40: Wiring Diagram Sequence Of Operation

    Electrical System Section 6 Wiring Diagram Sequence of L2 or N Operation Ground Water Valve (21) SELF-CONTAINED MODELS (20) (55) (99) (89) (61) (22) High Initial Start-Up or Start-Up After Control Board Harvest Valve Pressure (77) Automatic Shut-Off Cutout (88) (60) (80) Dump Valve...
  • Page 41 Section 6 Electrical System 2. REFRIGERATION SYSTEM L2 or N START-UP Ground Water Valve (99) (21) (20) The compressor starts after the 45- (55) (89) (61) (22) second water purge, and it remains High Control Board Harvest Valve Pressure on throughout the Freeze and (77) Cutout (88)
  • Page 42 Electrical System Section 6 Freeze Sequence L2 or N 3. PRE-CHILL Ground Water Valve (99) (21) (20) (55) (89) To pre-chill the evaporator, the (22) (61) High compressor runs for 30 seconds (60 Control Board Harvest Valve Pressure (77) seconds initial cycle) prior to water Cutout (88) (60)
  • Page 43 Section 6 Electrical System 4. FREEZE L2 or N Ground The water pump starts after the pre- Water Valve (99) (21) (20) chill. An even flow of water is directed (55) (89) (22) (61) across the evaporator and into each High Control Board Harvest Valve...
  • Page 44 Electrical System Section 6 Harvest Sequence L2 or N Ground 5. WATER PURGE Water Valve (99) (21) (20) (55) (89) The harvest valve(s) opens at the (22) (61) High beginning of the water purge to divert Control Board Harvest Valve Pressure (77) Cutout...
  • Page 45 Section 6 Electrical System 6. HARVEST L2 or N Ground The harvest valve(s) remains open Water Valve (99) (21) (20) and the refrigerant gas warms the (55) (89) (22) (61) evaporator. This causes the cubes to High Control Board Harvest Valve Pressure slide, as a sheet, off the evaporator (77)
  • Page 46 Electrical System Section 6 Automatic Shut-Off 7. AUTOMATIC SHUT-OFF L2 or N Ground When the storage bin is full at the Water Valve (99) (21) (20) end of a harvest cycle, the sheet of (55) (89) (22) (61) cubes fails to clear the water curtain High Control Board Harvest Valve...

  • Page 47: Wiring Diagrams

    Section 6 Electrical System Wiring Diagrams The following pages contain electrical wiring diagrams. Be sure you are referring to the correct diagram for the ice machine which 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 overloads)

  • Page 48: S0850M - Self Contained - 1 Phase

    Electrical System Section 6 S0850M - SELF CONTAINED - 1 PHASE L2 or N Ground (99) Water Valve (20) (21) (89) (55) (22) (61) Control Harvest Valve High Pressure Board Cutout (77) (88) (60) (80) Dump Valve (76) (75) (81)

  • Page 49: S0850M - Self Contained - 3 Phase

    Section 6 Electrical System S0850M - SELF CONTAINED - 3 PHASE (99) Water Valve Ground (20) (21) (61) (22) Control (89) (55) Board Harvest Valve (77) High Pressure (80) (60) Cutout (88) Dump Valve (76) (81) Water Pump (57) (98) (99) Trans.

  • Page 50: Component Specifications And Diagnostics

    Electrical System Section 6 Component Specifications and Diagnostics MAIN FUSE BIN SWITCH Function Function The control board fuse stops ice machine operation if Movement of the water curtain controls bin switch electrical components fail causing high amp draw. operation. The bin switch has two main functions: Specifications 1.
  • Page 51 Section 6 Electrical System Symptoms Water Curtain Removal Notes Bin Switch Fails Open The water curtain must be on (bin switch closed) to start ice making. While a freeze cycle is in progress, the water • The ice machine will not start with the toggle switch curtain can be removed and installed at any time without in the ice position, but runs normally with the toggle interfering with the electrical control sequence.

  • Page 52: Compressor Electrical Diagnostics

    Electrical System Section 6 COMPRESSOR ELECTRICAL DIAGNOSTICS Determine if the Compressor is Seized The compressor will not start or will trip repeatedly on Check the amp draw while the compressor is trying to overload. start. Check Resistance (Ohm) Values COMPRESSOR DRAWING LOCKED ROTOR NOTE: Compressor windings can have very low ohm The two likely causes of this are: values.

  • Page 53: Ptcr Diagnostics

    Section 6 Electrical System PTCR DIAGNOSTICS Compressor Start Sequence What is a PTCR? PTCR’s provide additional starting torque by increasing the current in the auxiliary (start) winding during starting. A PTCR (or Positive Temperature Coefficient Resistor) is The PTCR is wired across the run capacitor (in series made from high-purity, semi-conducting ceramics.
  • Page 54 Electrical System Section 6 S-Model Automatic Shut-Off and Restart Troubleshooting PTCR’s When the storage bin is full at the end of a harvest cycle, WHY A GOOD PTCR MAY FAIL the sheet of cubes fails to clear the water curtain and will TO START THE COMPRESSOR hold it open.
  • Page 55 • The voltage at the compressor during start-up is too low. Manitowoc ice machines are rated at ±10% of nameplate voltage at compressor start-up. (Ex: An ice machine rated at 208-230 should have a compressor start-up voltage between 187 and 253 volts.)

  • Page 56: Diagnosing Start Components

    Electrical System Section 6 DIAGNOSING START COMPONENTS ICE/OFF/CLEAN TOGGLE SWITCH If the compressor attempts to start, or hums and trips the Function overload protector, check the start components before The switch is used to place the ice machine in ICE, OFF replacing the compressor.

  • Page 57: Electronic Control Board

    Section 6 Electrical System ELECTRONIC CONTROL BOARD N 115V L2 208-230V PRIMARY POWER SUPPLY AC LINE VOLTAGE ELECTRICAL PLUG (NUMBERS MARKED ON WIRES) MAIN FUSE (7A) AIR COMPRESSOR (NOT USED ON ALL MODELS) WATER PURGE CLEAN LIGHT (YELLOW) ADJUSTMENT LEFT BIN LIGHT (GREEN) RIGHT BIN LIGHT (GREEN) REMOTE BIN LIGHT (GREEN) WATER LEVEL LIGHT (GREEN)
  • Page 58 Electrical System Section 6 General Inputs S-Model control boards use a dual voltage transformer. The control board, along with inputs, controls all This means only one control board is needed for both electrical components, including the ice machine 115V and 208-230V use. sequence of operation.

  • Page 59: Ice Thickness Probe (Harvest Initiation)

    Ice Thickness Probe Cleaning The control board locks the ice machine in the freeze 1. Mix a solution of Manitowoc ice machine cleaner cycle for six minutes. If water contacts the ice thickness and water (2 ounces of cleaner to 16 ounces of probe during these six minutes, the harvest light will water) in a container.

  • Page 60: Diagnosing Ice Thickness Control Circuitry

    Electrical System Section 6 DIAGNOSING ICE THICKNESS CONTROL CIRCUITRY Ice Machine Does Not Cycle Into Harvest When Water Contacts The Ice Thickness Control Probe Step 1 Bypass the freeze time lock-in feature by moving the ICE/OFF/CLEAN switch to OFF and back to ICE. Step 2 Wait until the water starts to flow over the evaporator (freeze cycle).

  • Page 61: Water Level Control Circuitry

    Section 6 Electrical System Water Level Control Circuitry FREEZE CYCLE CIRCUITRY Manitowoc’s electronic sensing circuit does not rely on WATER LEVEL PROBE LIGHT float switches or timers to maintain consistent water The water level probe circuit can be monitored by level control.

  • Page 62: Diagnosing Water Level Control Circuitry

    Electrical System Section 6 DIAGNOSING WATER LEVEL CONTROL CIRCUITRY Problem: Water Trough Overfilling During The Step 2 Wait until the freeze cycle starts Freeze Cycle (the freeze cycle starts when the water pump energizes). Step 1 Start a new freeze sequence by moving the ICE/ Step 3 Disconnect water level probe wire from control OFF/CLEAN toggle switch to OFF, then back to ICE.
  • Page 63 Section 6 Electrical System Problem: Water Will Not Run Into The Sump Trough Step 2 Wait until the freeze cycle starts (approximately During The Freeze Cycle 45 seconds, the freeze cycle starts when the compressor energizes). Step 1 Verify water is supplied to the ice machine, and then start a new freeze sequence by moving the ICE/ Step 3 Disconnect the water level probe from the water OFF/CLEAN toggle switch to OFF then back to ICE.

  • Page 64: Diagnosing An Ice Machine That Will Not Run

    Electrical System Section 6 Diagnosing An Ice Machine That Will Not Run Warning High (line) voltage is applied to the control board (terminals #55 and #56) at all times. Removing control board fuse or moving the toggle switch to OFF will not remove the power supplied to the control board.
  • Page 65 Section 6 Electrical System S0850M - SELF CONTAINED - 1 PHASE WITH TERMINAL BOARD SV2071 6-27 Part Number 80-1558-3...
  • Page 66 Electrical System Section 6 THIS PAGE INTENTIONALLY LEFT BLANK 6-28 Part Number 80-1558-3...

  • Page 67: Refrigeration System

    Section 7 . Refrigeration System Section 7. Refrigeration System Sequence of Operation SELF-CONTAINED WATER -COOLED MODELS EVAPORATOR HEAT EXCHANGER EXPANSION VALVE HOT GAS SOLENOID VALVE COMPRESSOR AIR OR WATER STRAINER CONDENSER DRIER RECEIVER (WATER COOLED ONLY) HIGH PRESSURE VAPOR HIGH PRESSURE LIQUID LOW PRESSURE LIQUID LOW PRESSURE VAPOR SV1569...
  • Page 68 . Refrigeration System Section 7 E V A P O R A T O R H E A T E X C H A N G E R E X P A N S I O N V A L V E H O T G A S S O L E N O I D V A L V E A I R O R W A T E R C O M P R E S S O R...

  • Page 69: Operational Analysis (Diagnostics)

    Section 7 . Refrigeration System Operational Analysis (Diagnostics) 2. An ice machine that is low on charge may cause a good expansion valve to starve. If a service GENERAL technician fails to verify the system charge, he may When analyzing the refrigeration system, it is important replace the expansion valve in error.

  • Page 70: Before Beginning Service

    . Refrigeration System Section 7 BEFORE BEGINNING SERVICE 2. Refer to the appropriate 24 Hour Ice Production Chart. Use the operating conditions determined in Ice machines may experience operational problems only Step 1 to find published 24 hour ice production. during certain times of the day or night.

  • Page 71: Installation/Visual Inspection Checklist

    Section 7 . Refrigeration System INSTALLATION/VISUAL INSPECTION CHECKLIST WATER SYSTEM CHECKLIST A water-related problem often causes the same Possible Problem Corrective Action symptoms as a refrigeration system component Ice machine is not level Level the ice machine malfunction. Water filtration is plugged (if Install a new water filter Water system problems must be identified and used)

  • Page 72: Ice Formation Pattern

    . Refrigeration System Section 7 ICE FORMATION PATTERN 2. Extremely Thin at Evaporator Outlet Evaporator ice formation pattern analysis is helpful in ice There is no ice, or a considerable lack of ice formation at machine diagnostics. the outlet of the evaporator. Analyzing the ice formation pattern alone cannot Examples: No ice at all at the outlet half of the diagnose an ice machine malfunction.
  • Page 73 Section 7 . Refrigeration System 3. Extremely Thin at Evaporator Inlet 5. No Ice Formation There is no ice, or a considerable lack of ice formation at The ice machine operates for an extended period, but the inlet of the evaporator. Examples: The ice at the there is no ice formation at all on the evaporator.

  • Page 74: Safety Limits

    . Refrigeration System Section 7 SAFETY LIMITS Analyzing Why Safety Limits May Stop the Ice Machine General According to the refrigeration industry, a high percentage In addition to standard safety controls, such as high of compressors fail as a result of external causes. These pressure cut-out, the control board has two built in safety can include: flooding or starving expansion valves, dirty limit controls which protect the ice machine from major...
  • Page 75 Section 7 . Refrigeration System Safety Limit #1 Refer to previous page for safety limit operation. Freeze time exceeds 60 minutes for 6 consecutive freeze cycles. Possible Cause Check/Correct Improper installation See “Installation/Visual Inspection Checklist” Water system Low water pressure [20 psi (138 kPa) min.] High water pressure [80 psi (552 kPa) max.] High water temperature (90°F/32.2°C max.) Clogged water distribution tube...
  • Page 76 . Refrigeration System Section 7 Safety Limit #2 Refer to page 7-8 for safety limit operation. Harvest time exceeds 3.5 minutes for 500 consecutive harvest cycles. Possible Cause Check/Correct Improper installation See “Installation/Visual Inspection Checklist” Water system Water area (evaporator) dirty Dirty/defective water dump valve Vent tube not installed on water outlet drain Water freezing behind evaporator...

  • Page 77: Analyzing Discharge Pressure During Freeze Or Harvest Cycle

    Section 7 . Refrigeration System ANALYZING DISCHARGE PRESSURE 3. Perform an actual discharge pressure check. DURING FREEZE OR HARVEST CYCLE Procedure Freeze Cycle Harvest Cycle PSIG (kPa) PSIG (kPa) 1. Determine the ice machine operating conditions: Beginning of Cycle __________ __________ Middle of Cycle __________...

  • Page 78: Analyzing Suction Pressure During Freeze Cycle

    . Refrigeration System Section 7 ANALYZING SUCTION PRESSURE NOTE: Analyze discharge pressure before analyzing DURING FREEZE CYCLE suction pressure. High or low discharge pressure may be causing high or low suction pressure. The suction pressure gradually drops throughout the freeze cycle. The actual suction pressure (and drop rate) changes as the air and water temperatures entering the ice machine change.
  • Page 79 Section 7 . Refrigeration System Freeze Cycle Suction Pressure High Checklist Possible Cause Check/Correct Improper installation See “Installation/Visual Inspection Checklist” Discharge pressure Discharge pressure is too high, and is affecting low side (See “Freeze Cycle Discharge Pressure High Checklist” ) Improper refrigerant charge Overcharged Wrong type of refrigerant...

  • Page 80: Single Expansion Valve Ice Machines - Comparing Evaporator Inlet And Outlet Temperatures

    . Refrigeration System Section 7 SINGLE EXPANSION VALVE ICE MACHINES - Use this procedure to document freeze cycle inlet and COMPARING EVAPORATOR INLET AND outlet temperatures. OUTLET TEMPERATURES 1. Use a quality temperature meter, capable of taking NOTE: This procedure will not work on the dual temperature readings on curved copper lines.

  • Page 81: Harvest Valve Temperature Check

    Section 7 . Refrigeration System HARVEST VALVE TEMPERATURE CHECK 3. Feel the compressor discharge line. General Warning A harvest valve requires a critical orifice size. This The inlet of the harvest valve and the compressor meters the amount of hot gas flowing into the evaporator discharge line could be hot enough to burn your during the harvest cycle.

  • Page 82: How To Use The Refrigeration System Operational Analysis Tables

    . Refrigeration System Section 7 HOW TO USE THE REFRIGERATION SYSTEM Final Analysis OPERATIONAL ANALYSIS TABLES The column with the highest number of check marks General identifies the refrigeration problem. These tables must be used with charts, checklists and COLUMN 1 - HARVEST VALVE LEAKING other references to eliminate refrigeration components A leaking harvest valve must be replaced.

  • Page 83: Refrigeration System Operational Analysis Tables

    Section 7 . Refrigeration System REFRIGERATION SYSTEM OPERATIONAL ANALYSIS TABLES S Models Single Expansion Valve This table must be used with charts, checklists and other references to eliminate refrigeration components not listed on the table and external items and problems, which can cause good refrigeration components to appear defective.

  • Page 84: Pressure Control Specifications And Diagnostics

    . Refrigeration System Section 7 Pressure Control Specifications and Diagnostics HIGH PRESSURE CUT-OUT (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 Cut-out: 450 psig ±10 (3103 kPa ±69, 31 Bar ±.69)

  • Page 85: Cycle Time/24 Hour Ice Production/Refrigerant Pressure Charts

    Section 7 . Refrigeration System Cycle Time/24 Hour Ice Production/ S0850M SERIES Refrigerant Pressure Charts Self-Contained Water-Cooled These charts are used as guidelines to verify correct ice NOTE: These characteristics may vary depending on machine operation. operating conditions. Accurate collection of data is essential to obtain the Cycle Times correct diagnosis.

  • Page 86: Refrigerant Recovery/Evacuation And Recharging

    Follow the two-stage vacuum pump. manufacturer’s recommendations. MANIFOLD SET Important OPEN OPEN Manitowoc Ice, Inc. assumes no responsibility for the use of contaminated refrigerant. Damage resulting from the use of contaminated refrigerant is BACKSEATED BACKSEATED LOW SIDE HIGH SIDE the sole responsibility of the servicing company.
  • Page 87 3. Open the high side manifold gauge valve, and backseat the high side service valve. The charge is critical on all Manitowoc ice machines. Use a scale or a charging cylinder to 4. Open the charging cylinder and add the proper ensure the proper charge is installed.
  • Page 88 . Refrigeration System Section 7 EVAPORATOR HEAT EXCHANGER EXPANSION VALVE HOT GAS SOLENOID VALVES LOW SIDE SERVICE VALVE (BACKSEATED) COMPRESSOR STRAINER HARVEST PRESSURE HARVEST CHECK SOLENOID PRESSURE VALVE VALVE REGULATING VALVE HIGH SIDE LIQUID SERVICE VALVE LINE (BACKSEATED) SOLENOID DISCHARGE LINE QUICK CONNECT DRIER SCHRAEDER FITTING...

  • Page 89: System Contamination Clean-Up

    If a refrigerant test kit indicates harmful levels of Important contamination, or if a test kit is not available, inspect the Manitowoc Ice, Inc. assumes no responsibility for compressor oil. the use of contaminated refrigerant. Damage 1. Remove the refrigerant charge from the ice resulting from the use of contaminated refrigerant is machine.
  • Page 90 . Refrigeration System Section 7 Mild System Contamination Cleanup Procedure Severe System Contamination Cleanup Procedure 1. Replace any failed components. 1. Remove the refrigerant charge. 2. If the compressor is good, change the oil. 2. Remove the compressor. 3. Replace the liquid line drier. 3.

  • Page 91: Replacing Pressure Controls Without Removing Refrigerant Charge

    Section 7 . Refrigeration System 10. Follow the normal evacuation procedure, except REPLACING PRESSURE CONTROLS WITHOUT REMOVING REFRIGERANT CHARGE replace the evacuation step with the following: This procedure reduces repair time and cost. Use it Important when any of the following components require replacement, and the refrigeration system is operational Dry nitrogen is recommended for this procedure.
  • Page 92 . Refrigeration System Section 7 SV1406 Figure 7-10. Using Pinch-Off Tool 7-26 Part Number 80-1558-3...

  • Page 93: Filter-Driers

    Section 7 . Refrigeration System FILTER-DRIERS TOTAL SYSTEM REFRIGERANT CHARGES The filter-driers used on Manitowoc ice machines are Important manufactured to Manitowoc specifications. This information is for reference only. Refer to the The difference between Manitowoc driers and off-the- ice machine serial number tag to verify the system shelf driers is in filtration.

  • Page 94: Refrigerant Definitions

    . Refrigeration System Section 7 REFRIGERANT DEFINITIONS Reclaim Recover To reprocess refrigerant to new product specifications (see below) by means which may include distillation. A To remove refrigerant, in any condition, from a system chemical analysis of the refrigerant is required after and store it in an external container, without necessarily processing to be sure that product specifications are testing or processing it in any way.

  • Page 95: Refrigerant Re-Use Policy

    Important • Recovered refrigerant must come from a Manitowoc Ice, Inc. assumes no responsibility for “contaminant-free” system. To decide whether use of contaminated refrigerant. Damage resulting the system is contaminant free, consider: from the use of contaminated, recovered, or –...

  • Page 96: Hfc Refrigerant Questions And Answers

    . Refrigeration System Section 7 HFC REFRIGERANT QUESTIONS AND ANSWERS Manitowoc uses R-404A and R-134A HFC refrigerants with ozone depletion potential (ODP) factors of zero (0.0). R- 404A is used in ice machines and reach-in freezers and R-134A is used in reach-in refrigerators. 1.
  • Page 97 Section 7 . Refrigeration System THIS PAGE INTENTIONALLY LEFT BLANK 7-31 Part Number 80-1558-3...
  • Page 98 . Refrigeration System Section 7 THIS PAGE INTENTIONALLY LEFT BLANK 7-32 Part Number 80-1558-3...
  • Page 100 • Improve Your Service Techniques • Network with Your Peers • 4 1/2 Days of Intensive Training on Manitowoc Ice Machines • Extensive “Hands On” Training on a Variety of Equipment • Breakfast, Lunch and Hotel Room Included with Tuition •...

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