S Model S0850M Ice Machines 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.
Safety Notices Procedural Notices As you work on a S-Series Ice Machine, be sure to pay close attention to the safety notices in this manual. Disregarding the notices may lead to serious injury and/ or damage to the ice machine. As you work on a S-Series Ice Machine, be sure to read the procedural notices in this manual. These notices supply helpful information which may assist you as you work.
Table of Contents Section 1 General Information Model Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . How to Read a Model Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ice Cube Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bin Caster . . . .
Table of Contents (continued) Section 3 Ice Machine Operation Component Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sequence Of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Initial Start-Up or Start-Up After Automatic Shut-Off . . . . . . . . . . . . . . . . . . Freeze Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Harvest Sequence . . . . . . . . . . . .
Table of Contents (continued) Section 6 Electrical System Energized Parts Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Self-Contained Water-Cooled Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wiring Diagram Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Self-Contained Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wiring Diagrams . . . . . . . . . . . . . . . . . . . . .
Table of Contents (continued) Cycle Time/24 Hour Ice Production/Refrigerant Pressure Charts . . . . . . . . . Refrigerant Recovery/Evacuation and Recharging . . . . . . . . . . . . . . . . . . . . . Normal Self-Contained Model Procedures . . . . . . . . . . . . . . . . . . . . . . . . . System Contamination Clean-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Replacing Pressure Controls Without Removing Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section 1 General Information Section 1 General Information Model Numbers How to Read a Model Number This manual covers the following models: # CUBE SIZE Self-Contained Water-Cooled SD0853WM SY0855WM 3 5 PERSONAL INJURY POTENTIAL Do not operate equipment that has been misused, abused, neglected, damaged, or altered/modified from that of original manufactured specifications. DICE WATER-COOLED HALF-DICE WATER-COOLED MARlNE MODEL NOTE: Model numbers ending in 3 indicate a 3-phase unit.
General Information Section 1 Accessories MANITOWOC CLEANER AND SANITIZER Contact your Manitowoc distributor for these optional accessories: Manitowoc Ice Machine Cleaner and Sanitizer are available in convenient 16 oz. (473 ml) bottles. These are the only cleaner and sanitizer approved for use with Manitowoc products. BIN CASTER Replaces standard legs. ICE BAGGER Maximize profits from bagged ice sales with this convenient accessory.
Section 1 General Information Model/Serial Number Location These numbers are required when requesting information from your local Manitowoc distributor, or Manitowoc Ice, Inc. The model and serial number are listed on the MODEL/ SERIAL NUMBER DECAL affixed to the ice machine, remote condenser and storage bin.
General Information Section 1 Owner Warranty Registration Card GENERAL EXCLUSIONS The packet containing this manual also includes warranty information. Warranty coverage begins the day your new ice machine is installed. The following items are not included in the ice machine’s warranty coverage: Important Complete and mail the OWNER WARRANTY REGISTARATION CARD as soon as possible to validate the installation date.
Section 2 Installation Instructions Section 2 Installation Instructions General These instructions are provided to assist the qualified installer. Check your local Yellow Pages for the name of the nearest Manitowoc distributor, or call Manitowoc Ice, Inc. for information regarding start-up services. Important Failure to follow these installation guidelines may affect warranty coverage. Ice Machine Dimensions S0850M ICE MACHINES WATER COOLED ELECTRICAL 2.20" (5.58cm) H A B 1.81" (4.59cm) 4.21" (10.
Installation Instructions Section 2 Location of Ice Machine Ice Machine Heat of Rejection 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 free of airborne and other contaminants. • The air temperature must be at least 35°F (1.6°C), but must not exceed 110°F (43.4°C). • The location must not be near heat-generating equipment or in direct sunlight.
Section 2 Installation Instructions Electrical Service FUSE/CIRCUIT BREAKER GENERAL A separate fuse/circuit breaker must be provided for each ice machine. Circuit breakers must be H.A.C.R. rated (does not apply in Canada). ! Warning All wiring must conform to local, state and national codes. MINIMUM CIRCUIT AMPACITY VOLTAGE The minimum circuit ampacity is used to help select the wire size of the electrical supply. (Minimum circuit ampacity is not the ice machine’s running amp load.
Installation Instructions Section 2 Self-Contained Electrical Wiring Connections ! Warning These diagrams are not intended to show proper wire routing, wire sizing, disconnects, etc., only the correct wire connections. SELF CONTAINED ICE MACHINE 208-230/3/60 All electrical work, including wire routing and grounding, must conform to local, state and national electrical codes. Though wire nuts are shown in the drawings, the ice machine field wiring connections may use either wire nuts or screw terminals.
Section 2 Installation Instructions Water Supply and Drain Requirements DRAIN CONNECTIONS WATER SUPPLY Follow these guidelines when installing drain lines to prevent drain water from flowing back into the ice machine and storage bin: Local water conditions may require treatment of the water to inhibit scale formation, filter sediment, and remove chlorine odor and taste.
Installation Instructions Section 2 WATER SUPPLY AND DRAIN LINE SIZING/CONNECTIONS ! Caution Plumbing must conform to state and local codes. Location Water Temperature Water Pressure Ice Machine Fitting Ice Making Water Inlet 35°F (1.6°C) Min. 90°F (32.2°C) Max. 20 psi (137.9 kPA) Min. 80 psi (551.5 kPA) Max. 3/8" Female Pipe Thread Tubing Size Up to Ice Machine Fitting 3/8" (.95 cm) minimum inside diameter Ice Making Water Drain --- --- 1/2" Female Pipe Thread 1/2" (1.
Section 2 Installation Check List Installation Instructions Are the ice machine and bin drains vented? Is the Ice Machine level? Has all of the internal packing been removed? Are all electrical leads free from contact with refrigeration lines and moving equipment? Have all of the electrical and water connections been made? Has the owner/operator been instructed regarding maintenance and the use of Manitowoc Cleaner and Sanitizer? Has the supply voltage been tested and checked against the rating on the
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. Adjustments and maintenance procedures outlined in this manual are not covered by the warranty.
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 Pump Water Inlet Location Water Inlet Valve (Located in Refrigeration Compartment) sv3150 Part Number 80-1558-3 3-1
Ice Machine Operation Section 3 Sequence Of Operation NOTE: The toggle switch must be in the ice position and the water curtain must be in place on the evaporator before the ice machine will start. INITIAL START-UP OR START-UP AFTER AUTOMATIC SHUT-OFF 1. Water Purge Before the compressor starts, the water pump and water dump solenoid are energized for 45 seconds, to completely purge the ice machine of old water. This feature ensures that the ice making cycle starts with fresh water.
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 purge to divert hot refrigerant gas into the evaporator. When the storage bin is full at the end of a harvest sequence, the sheet of cubes fails to clear the water curtain and will hold it open. After the water curtain is held open for 30 seconds, the ice machine shuts off.
Ice Machine Operation Section 3 Operational Checks ICE THICKNESS CHECK GENERAL The ice thickness probe is factory-set to maintain the ice bridge thickness at 1/8" (.32 cm). Manitowoc ice machines are factory-operated and adjusted before shipment. Normally, new installations do not require any adjustment.
Section 3 Ice Machine Operation HARVEST SEQUENCE WATER PURGE The harvest sequence water purge adjustment may be used when the ice machine is hooked up to special water systems, such as a de-ionized water treatment system. ! Warning • During the harvest sequence water purge, the water fill valve energizes and de-energizes by time. The water purge must be at the factory setting of 45 seconds for the water fill valve to energize during the last 15 seconds of the water purge.
Ice Machine Operation Section 3 THIS PAGE INTENTIONALLY LEFT BLANK 3-6 Part Number 80-1558-3
Section 4 Maintenance Section 4 Maintenance General You are responsible for maintaining the ice machine in accordance with the instructions in this manual. Maintenance procedures are not covered by the warranty. ! Warning If you do not understand the procedures or the safety precautions that must be followed, call your local Manitowoc service representative to perform the maintenance procedures for you.
Maintenance Section 4 Guardian™ Slime is a leading cause of ice machine breakdowns and biological growth is a health concern. The Guardian™ system releases chlorine dioxide on a controlled basis to inhibit the growth of bacteria and fungi that form slime and cause malodors in the food zone of ice machines. SACHET REPLACEMENT PROCEDURE 1. Loosen the left screw and open the left front door. The right front panel does not need to be removed.
Section 4 Maintenance Interior Cleaning and Sanitizing ! Caution GENERAL Clean and sanitize the ice machine every six months for efficient operation. If the ice machine requires more frequent cleaning and sanitizing, consult a qualified service company to test the water quality and recommend appropriate water treatment. An extremely dirty ice machine must be taken apart for cleaning and sanitizing.
Maintenance Section 4 SANITIZING PROCEDURE Use sanitizer to remove algae or slime. Do not use it to remove lime scale or other mineral deposits. Step 1 Set the toggle switch to the OFF position after ice falls from the evaporator at the end of a Harvest cycle. Or, set the switch to the OFF position and allow the ice to melt off the evaporator. Step 4 Use the sanitizing solution and a sponge or cloth to sanitize (wipe) all parts and interior surfaces of the ice machine. Sanitize the following areas: A.
Section 4 Maintenance REMOVAL OF PARTS FOR CLEANING/SANITIZING 1. Turn off the electrical and water supply to the ice machine (and dispenser when applicable). 5. Use a soft-bristle brush or sponge (NOT a wire brush) to carefully clean the parts. ! Caution ! Warning Disconnect electric power to the ice machine (and dispenser if applicable) at the electric switch box before proceeding. ! Caution 2. Remove all ice from the bin. 3. Remove the water curtain and the components you want to clean or sanitize.
Maintenance Section 4 2. Ice Thickness Probe 1. Water Curtain A. Gently flex the curtain in the center and remove it from the right side. A. Compress the hinge pin on the top of the ice thickness probe. B. Slide the left pin out. STEP 1 STEP 2 COMPRESS HINGE PIN TO REMOVE SV3153 SV3135 Water Curtain Removal Ice Thickness Probe Removal B. Pivot the ice thickness probe to disengage one pin then the other. The ice thickness probe can be cleaned at this point without complete removal.
Section 4 Maintenance 3. Water Distribution Tube ! Warning Removing the distribution tube while the water pump is running will allow water to spray from ice machine. Disconnect the electrical power to the ice machine and dispenser at the electric service switch box and turn off the water supply. 4. Water Trough A. Depress tabs on right and left side of the water trough. B. Allow front of water trough to drop as you pull forward to disengage the rear pins.
Maintenance Section 4 Water Pump Water Level Probe 1. Remove the water trough. ! Warning ! Warning Disconnect the electrical power to the ice machine at the electrical disconnect before proceeding. 2. The water level probe normally does not require removal for cleaning. The probe can be wiped and cleaned in place or proceed to step 3. 3. Pull the water level probe straight down to disengage.
Section 4 Maintenance Water Dump Valve The water dump valve normally does not require removal for cleaning. To determine if removal is necessary: 1. Locate the water dump valve. 2. Set the toggle switch to ICE. 3. While the ice machine is in the freeze mode, check the dump valve’s clear plastic outlet drain hose for leakage. Important The plunger and the inside of the enclosing tube must be completely dry before assembly.
Maintenance Evaporator Tray Removal 1. Remove the water trough. 2. Remove thumbscrew on left side of tray. Section 4 Drain Line Check Valve The drain line check valve normally does not require removal for cleaning. Water loss from the sump trough will indicate removal and cleaning are required. 3. Allow left side of tray to drop as you pull the tray to the left side. Continue until the outlet tube disengages from the right side. sv3154 1. Remove check valve and tube assembly. A.
Section 4 Maintenance Removing the Front Panel Water Inlet Valve The water inlet valve normally does not require removal for cleaning. Refer to Section 5 for a list of causes for “No Water Entering Water Trough” or “Water Overflows Water Trough. 1. Disconnect power to ice machine. 2. Loosen thumbscrews. Do not remove they are retained by o-rings to prevent loss.. 1. When the ice machine is off, the water inlet valve must completely stop water flow into the machine. 2.
Maintenance Section 4 Removal from Service/Winterization GENERAL Special precautions must be taken if the ice machine is to be removed from service for an extended period of time or exposed to ambient temperatures of 32°F (0°C) or below. ! Caution WATER-COOLED ICE MACHINES 1. Perform steps 1-6 under “Self-Contained Air-Cooled Ice Machines.” 2. Disconnect the incoming water and drain lines from the water-cooled condenser. 3.
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 Ice machine does not operate. Possible Cause No electrical power to the ice machine and/or condensing unit. ICE/OFF/CLEAN toggle switch set improperly. Water curtain stuck open.
Before Calling For Service Problem Ice machine produces shallow or incomplete cubes, or the ice fill pattern on the evaporator is incomplete. Section 5 Possible Cause Ice thickness probe is out of adjustment. Water trough level is too low. Water inlet valve filter screen is dirty. Water filtration is poor. Hot incoming water. Water inlet valve is not working. Incorrect incoming water pressure. Ice machine is not level. Low ice capacity. Water inlet valve filter screen is dirty.
Section 6 Electrical System Section 6 Electrical System Energized Parts Charts SELF-CONTAINED WATER-COOLED MODELS Control Board Relays Ice Making Sequence Of Operation 1 2 3 Water Pump Harvest Valve (Left) Harvest Valve (Right)* START-UP 1 1. Water Purge On On 2. Refrigeration System Start-Up Off On FREEZE SEQUENCE 3. Pre-Chill 4. Freeze Off On Off Off 5 Not Used Water Inlet Valve Dump Valve On (when used) Off Off On Off Off May Cycle On/Off during the first 45 sec.
Electrical System Wiring Diagram Sequence of Operation Section 6 L2 or N L1 Ground SELF-CONTAINED MODELS Initial Start-Up or Start-Up After Automatic Shut-Off (89) (20) (55) (61) High Pressure Cutout (88) The harvest valve(s) is also energized during the water purge. In the case of an initial refrigeration start-up, it stays on for an additional 5 seconds (50 seconds total). (42) (99) (22) Control Board (2) (6) (5) (1) (7) (4) 1.
Section 6 2. REFRIGERATION SYSTEM START-UP The compressor starts after the 45second water purge, and it remains on throughout the Freeze and Harvest cycles. Electrical System L2 or N L1 Ground (89) (20) (55) (61) High Pressure Cutout (88) (42) Harvest Valve (77) (80) Dump Valve (76) (81) (60) (75) Water Pump (57) (98) Trans. The harvest valve(s) remains on for the first 5 seconds of the initial compressor start-up and then shuts off.
Electrical System Section 6 Freeze Sequence L2 or N L1 3. PRE-CHILL Ground To pre-chill the evaporator, the compressor runs for 30 seconds (60 seconds initial cycle) prior to water flow. (89) Water Valve (21) (22) (20) (55) (61) High Pressure Cutout (88) Control Board (2) (6) (5) (1) (7) (4) The water fill valve remains on until the water level probe is satisfied. (42) (99) Harvest Valve (77) (80) Dump Valve (76) (81) (60) (75) Water Pump (57) (98) Trans.
Section 6 4. FREEZE The water pump starts after the prechill. An even flow of water is directed across the evaporator and into each cube cell, where it freezes. Electrical System L2 or N L1 Ground (89) (20) (55) (61) High Pressure Cutout (88) Control Board (2) (6) (5) (1) (7) (4) The water fill valve will cycle off then on one more time to refill the water trough. (42) When sufficient ice has formed, the water flow (not the ice) contacts the ice thickness probes.
Electrical System Section 6 Harvest Sequence L2 or N L1 5. WATER PURGE Ground The harvest valve(s) opens at the beginning of the water purge to divert hot refrigerant gas into the evaporator. (89) The water pump continues to run, and the water dump valve energizes for 45 seconds to purge the water in the sump trough. The water fill valve energizes and de-energizes strictly by time. The water fill valve energizes for the last 15 seconds of the 45second water purge.
Section 6 6. HARVEST The harvest valve(s) remains open and the refrigerant gas warms the evaporator. This causes the cubes to slide, as a sheet, off the evaporator and into the storage bin. The sliding sheet of cubes swings the water curtain out, opening the bin switch. This momentary opening and closing of the bin switch terminates the Harvest Cycle and returns the ice machine to the Freeze Cycle (steps 3-4).
Electrical System Section 6 Automatic Shut-Off 7. AUTOMATIC SHUT-OFF L2 or N L1 Ground When the storage bin is full at the end of a harvest cycle, the sheet of cubes fails to clear the water curtain and holds it open. After the water curtain is held open for 30 seconds, the ice machine shuts off. (89) (20) (55) (61) High Pressure Cutout (88) The ice machine remains off until enough ice is removed from the storage bin to allow the sheet of cubes to drop clear of the water curtain.
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.
Electrical System Section 6 S0850M - SELF CONTAINED - 1 PHASE L1 L2 or N Ground (99) Water Valve (20) (89) (21) (55) (22) (61) (88) Control Board (2) High Pressure Cutout Harvest Valve (77) (60) (6) (80) (5) Dump Valve (76) (1) (7) (75) (81) Water Pump (4) (98) (57) (99) Trans.
Section 6 Electrical System S0850M - SELF CONTAINED - 3 PHASE L3 L2 (99) Water Valve L1 Ground (20) (21) (61) (89) (22) Control Board (55) Harvest Valve (3) High Pressure Cutout (77) (80) (60) (4) (88) (2) Dump Valve (76) (1) (5) (81) (6) Water Pump (57) (98) (99) Trans.
Electrical System Section 6 Component Specifications and Diagnostics MAIN FUSE BIN SWITCH Function Function The control board fuse stops ice machine operation if electrical components fail causing high amp draw. Movement of the water curtain controls bin switch operation. The bin switch has two main functions: 1. Terminating the harvest cycle and returning the ice machine to the freeze cycle. Specifications The main fuse is 250 Volt, 7 amp.
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 curtain can be removed and installed at any time without interfering with the electrical control sequence. • The ice machine will not start with the toggle switch in the ice position, but runs normally with the toggle switch in the clean position.
Electrical System Section 6 COMPRESSOR ELECTRICAL DIAGNOSTICS Determine if the Compressor is Seized The compressor will not start or will trip repeatedly on overload. Check the amp draw while the compressor is trying to start. Check Resistance (Ohm) Values COMPRESSOR DRAWING LOCKED ROTOR NOTE: Compressor windings can have very low ohm values. Use a properly calibrated meter. The two likely causes of this are: Perform the resistance test after the compressor cools.
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. The PTCR is wired across the run capacitor (in series with the start winding). A PTCR (or Positive Temperature Coefficient Resistor) is made from high-purity, semi-conducting ceramics. A PTCR is useful because of its resistance versus temperature characteristic.
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, the sheet of cubes fails to clear the water curtain and will hold it open. After the water curtain is held open for 7 seconds, the ice machine shuts off. To assure the PTCR has cooled, the ice machine remains off for 3 minutes before it can automatically restart.
Section 6 Electrical System There are other problems that may cause compressor start-up failure with a good PTCR in a new, properly wired ice machine. • The voltage at the compressor during start-up is too low. Model S0850M Room Manitowoc Cera-Mite Temperature Part Number Part Number Resistance 8504993 305C19 18-40 Ohms Manitowoc ice machines are rated at ±10% of nameplate voltage at compressor start-up.
Electrical System Section 6 DIAGNOSING START COMPONENTS ICE/OFF/CLEAN TOGGLE SWITCH If the compressor attempts to start, or hums and trips the overload protector, check the start components before replacing the compressor. Function Capacitor Specifications Visual evidence of capacitor failure can include a bulged terminal end or a ruptured membrane. Do not assume a capacitor is good if no visual evidence is present. A good test is to install a known good substitute capacitor.
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 ADJUSTMENT CLEAN LIGHT (YELLOW) LEFT BIN LIGHT (GREEN) RIGHT BIN LIGHT (GREEN) REMOTE BIN LIGHT (GREEN) WATER LEVEL LIGHT (GREEN) ICE LEVEL LIGHT (GREEN) HARVEST LIGHT (RED) SAFETY LIMIT 1 LIGHT (RED) SAFETY LIMIT 2 LIGHT (RED) ICE THICKNESS PROBE (3/16'' CONNECTION) AUTOMATIC CLEANIN
Electrical System Section 6 General Inputs S-Model control boards use a dual voltage transformer. This means only one control board is needed for both 115V and 208-230V use. The control board, along with inputs, controls all electrical components, including the ice machine sequence of operation. Prior to diagnosing, you must understand how the inputs affect the control board operation.
Section 6 Electrical System Ice Thickness Probe (Harvest Initiation) MAXIMUM FREEZE TIME HOW THE PROBE WORKS The control system includes a built-in safety which will automatically cycle the ice machine into harvest after 60 minutes in the freeze cycle. Manitowoc’s electronic sensing circuit does not rely on refrigerant pressure, evaporator temperature, water levels or timers to produce consistent ice formation. As ice forms on the evaporator, water (not ice) contacts the ice thickness probe.
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).
Section 6 Electrical System Water Level Control Circuitry FREEZE CYCLE CIRCUITRY WATER LEVEL PROBE LIGHT Manitowoc’s electronic sensing circuit does not rely on float switches or timers to maintain consistent water level control. During the freeze cycle, the water inlet valve energizes (turns on) and de-energizes (turns off) in conjunction with the water level probe located in the water trough. The water level probe circuit can be monitored by watching the water level light.
Electrical System Section 6 DIAGNOSING WATER LEVEL CONTROL CIRCUITRY Problem: Water Trough Overfilling During The Freeze Cycle Step 2 Wait until the freeze cycle starts (the freeze cycle starts when the water pump energizes). Step 1 Start a new freeze sequence by moving the ICE/ OFF/CLEAN toggle switch to OFF, then back to ICE. (if water flows with the switch off, check the water inlet valve).
Section 6 Electrical System Problem: Water Will Not Run Into The Sump Trough During The Freeze Cycle Step 1 Verify water is supplied to the ice machine, and then start a new freeze sequence by moving the ICE/ OFF/CLEAN toggle switch to OFF then back to ICE. Step 2 Wait until the freeze cycle starts (approximately 45 seconds, the freeze cycle starts when the compressor energizes). Step 3 Disconnect the water level probe from the water level probe terminal on the control board.
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. Step 1 2 3 4 5 6 7 6-26 Check Verify primary voltage supply to ice machine. Verify the high-pressure cutout is closed. Verify control board fuse is OK. Verify the bin switch functions properly.
Section 6 Electrical System S0850M - SELF CONTAINED 1 PHASE WITH TERMINAL BOARD 1 2 3 4 6 5 SV2071 Part Number 80-1558-3 6-27
Electrical System Section 6 THIS PAGE INTENTIONALLY LEFT BLANK 6-28 Part Number 80-1558-3
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 X COMPRESSOR STRAINER AIR OR WATER CONDENSER DRIER RECEIVER (WATER COOLED ONLY) HIGH PRESSURE VAPOR HIGH PRESSURE LIQUID LOW PRESSURE LIQUID LOW PRESSURE VAPOR SV1569 Figure 7-1.
. Refrigeration System Section 7 EVAPORATOR HEAT EXCHANGER EXPANSION VALVE HOT GAS SOLENOID VALVE COMPRESSOR STRAINER AIR OR WATER CONDENSER DRIER RECEIVER (WATER COOLED ONLY) HIGH PRESSURE VAPOR HIGH PRESSURE LIQUID LOW PRESSURE LIQUID LOW PRESSURE VAPOR SV1570 Figure 7-2. Self-Contained Harvest Cycle Harvest Cycle Refrigeration Sequence Hot gas flows through the energized harvest valve, heating the evaporator.
Section 7 Operational Analysis (Diagnostics) GENERAL When analyzing the refrigeration system, it is important to understand that different refrigeration component malfunctions may cause very similar symptoms. Also, many external factors can make good refrigeration components appear bad. These factors can include improper installation, or water system malfunctions such as hot incoming water supply or water loss. The following two examples illustrate how similar symptoms can result in a misdiagnosis. 1.
. Refrigeration System BEFORE BEGINNING SERVICE Ice machines may experience operational problems only during certain times of the day or night. A machine may function properly while it is being serviced, but malfunctions later. Information provided by the user can help the technician start in the right direction, and may be a determining factor in the final diagnosis. Section 7 2. Refer to the appropriate 24 Hour Ice Production Chart.
Section 7 . Refrigeration System INSTALLATION/VISUAL INSPECTION CHECKLIST Possible Problem Ice machine is not level Water filtration is plugged (if used) Water drains are not run separately and/or are not vented Part Number 80-1558-3 Corrective Action Level the ice machine Install a new water filter Run and vent drains according to the Installation Manual WATER SYSTEM CHECKLIST A water-related problem often causes the same symptoms as a refrigeration system component malfunction.
. Refrigeration System Section 7 ICE FORMATION PATTERN 2. Extremely Thin at Evaporator Outlet Evaporator ice formation pattern analysis is helpful in ice machine diagnostics. There is no ice, or a considerable lack of ice formation at the outlet of the evaporator. Analyzing the ice formation pattern alone cannot diagnose an ice machine malfunction.
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 inlet of the evaporator. Examples: The ice at the outlet of the evaporator reaches 1/8" to initiate a harvest, but there is no ice formation at all at the inlet of the evaporator. The ice machine operates for an extended period, but there is no ice formation at all on the evaporator.
. Refrigeration System SAFETY LIMITS General In addition to standard safety controls, such as high pressure cut-out, the control board has two built in safety limit controls which protect the ice machine from major component failures. Safety Limit #1: If the freeze time reaches 60 minutes, the control board automatically initiates a harvest cycle. If 6 consecutive 60-minute freeze cycles occur, the ice machine stops. Safety Limit #2: If the harvest time reaches 3.
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 Improper installation Water system Electrical system Miscellaneous Refrigeration system SAFETY LIMIT NOTES • Because there are many possible external problems, do not limit your diagnosis to only the items listed in this chart. • A continuous run of 100 harvests automatically erases the safety limit code.
. 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 Improper installation Water system Electrical system Refrigeration system SAFETY LIMIT NOTES • Because there are many possible external problems, do not limit your diagnosis to only the items listed in this chart. • A continuous run of 100 harvests automatically erases the safety limit code.
Section 7 . Refrigeration System 3. Perform an actual discharge pressure check. ANALYZING DISCHARGE PRESSURE DURING FREEZE OR HARVEST CYCLE Procedure 1. Determine the ice machine operating conditions: Air temp. entering condenser Air temp. around ice machine Water temp. entering sump trough ______ ______ ______ 2. Refer to Operating Pressure Chart for ice machine being checked. Use the operating conditions determined in step 1 to find the published normal discharge pressures.
. Refrigeration System Section 7 NOTE: Analyze discharge pressure before analyzing suction pressure. High or low discharge pressure may be causing high or low suction pressure. ANALYZING SUCTION PRESSURE DURING FREEZE CYCLE 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. This affects freeze cycle times.
Section 7 . Refrigeration System Freeze Cycle Suction Pressure High Checklist Possible Cause Improper installation Discharge pressure Improper refrigerant charge Other Check/Correct See “Installation/Visual Inspection Checklist” Discharge pressure is too high, and is affecting low side (See “Freeze Cycle Discharge Pressure High Checklist” ) Overcharged Wrong type of refrigerant Non-Manitowoc components in system H.P.R.
. Refrigeration System SINGLE EXPANSION VALVE ICE MACHINES COMPARING EVAPORATOR INLET AND OUTLET TEMPERATURES NOTE: This procedure will not work on the dual expansion valve ice machines. 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 using Manitowoc’s Refrigeration System Operational Analysis Table, can help diagnose an ice machine malfunction.
Section 7 . Refrigeration System HARVEST VALVE TEMPERATURE CHECK 3. Feel the compressor discharge line. General A harvest valve requires a critical orifice size. This meters the amount of hot gas flowing into the evaporator during the harvest cycle. If the orifice is even slightly too large or too small, long harvest cycles will result. A too-large orifice causes refrigerant to condense to liquid in the evaporator during the harvest cycle. This liquid will cause compressor damage.
. Refrigeration System HOW TO USE THE REFRIGERATION SYSTEM OPERATIONAL ANALYSIS TABLES General These tables must be used with charts, checklists and other references to eliminate refrigeration components not listed on the tables and external items and problems which can cause good refrigeration components to appear defective. The tables list five different defects that may affect the ice machine’s operation.
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.
. Refrigeration System Section 7 Pressure Control Specifications and Diagnostics HIGH PRESSURE CUT-OUT (HPCO) CONTROL Function Stops the ice machine if subjected to excessive highside pressure. The HPCO control is normally closed, and opens on a rise in discharge pressure. Specifications Cut-out: 450 psig ±10 (3103 kPa ±69, 31 Bar ±.69) Cut-in: Manual or automatic reset Must be below 300 psig (2068 kPa, 20.68 Bar ±.69) to reset Check Procedure 1. Set ICE/OFF/CLEAN switch to OFF. 2.
Section 7 . Refrigeration System Cycle Time/24 Hour Ice Production/ Refrigerant Pressure Charts S0850M SERIES These charts are used as guidelines to verify correct ice machine operation. NOTE: These characteristics may vary depending on operating conditions. Accurate collection of data is essential to obtain the correct diagnosis. Cycle Times • • Refer to “OPERATIONAL ANALYSIS TABLE” for the list of data that must be collected for refrigeration diagnostics.
. Refrigeration System Section 7 Refrigerant Recovery/Evacuation and Recharging NORMAL SELF-CONTAINED MODEL PROCEDURES SELF-CONTAINED RECOVERY/EVACUATION Refrigerant Recovery/Evacuation 1. Place the toggle switch in the OFF position. Do not purge refrigerant to the atmosphere. Capture refrigerant using recovery equipment. Follow the manufacturer’s recommendations. 2. Install manifold gauges, scale, and recovery unit or two-stage vacuum pump. MANIFOLD SET Important Manitowoc Ice, Inc.
Section 7 . Refrigeration System 2. Close the vacuum pump valve, the low side service valve, and the low side manifold gauge valve. Self-Contained Charging Procedures Important The charge is critical on all Manitowoc ice machines. Use a scale or a charging cylinder to ensure the proper charge is installed. 1. Be sure the toggle switch is in the OFF position. 4. Open the charging cylinder and add the proper refrigerant charge (shown on nameplate) through the discharge service valve. 5.
. Refrigeration System Section 7 HEAT EXCHANGER EVAPORATOR EXPANSION VALVE x HOT GAS SOLENOID VALVES LOW SIDE SERVICE VALVE (BACKSEATED) COMPRESSOR STRAINER HARVEST PRESSURE SOLENOID VALVE CHECK VALVE x HARVEST PRESSURE REGULATING VALVE x HIGH SIDE SERVICE VALVE (BACKSEATED) LIQUID LINE SOLENOID DISCHARGE LINE QUICK CONNECT SCHRAEDER FITTING DRIER REMOTE CONDENSER RECEIVER SERVICE VALVE 1/2 OPEN B CHECK VALVE R C HEAD PRESSURE CONTROL VALVE MANIFOLD SET TEE OPEN OPEN OPEN VACUUM PU
Section 7 . Refrigeration System SYSTEM CONTAMINATION CLEAN-UP General This section describes the basic requirements for restoring contaminated systems to reliable service. Important Manitowoc Ice, Inc. assumes no responsibility for the use of contaminated refrigerant. Damage resulting from the use of contaminated refrigerant is the sole responsibility of the servicing company.
. Refrigeration System Mild System Contamination Cleanup Procedure Section 7 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. Disassemble the harvest solenoid valve. If burnout deposits are found inside the valve, install a new harvest valve, and replace manifold strainer, TXV and harvest pressure regulating valve.
Section 7 . Refrigeration System 10. Follow the normal evacuation procedure, except replace the evacuation step with the following: Important Dry nitrogen is recommended for this procedure. This will prevent CFC release. 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. • Water regulating valve (water-cooled only) A.
. Refrigeration System Section 7 SV1406 Figure 7-10.
Section 7 . Refrigeration System TOTAL SYSTEM REFRIGERANT CHARGES FILTER-DRIERS The filter-driers used on Manitowoc ice machines are manufactured to Manitowoc specifications. The difference between Manitowoc driers and off-theshelf driers is in filtration. Manitowoc driers have dirtretaining filtration, with fiberglass filters on both the inlet and outlet ends. This is very important because ice machines have a back-flushing action which takes place during every harvest cycle.
. Refrigeration System Section 7 REFRIGERANT DEFINITIONS Reclaim Recover To reprocess refrigerant to new product specifications (see below) by means which may include distillation. A chemical analysis of the refrigerant is required after processing to be sure that product specifications are met. This term usually implies the use of processes and procedures available only at a reprocessing or manufacturing facility.
Section 7 . Refrigeration System REFRIGERANT RE-USE POLICY Manitowoc recognizes and supports the need for proper handling, re-use, and disposal of, CFC and HCFC 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’ products to achieve this. Important Manitowoc Ice, Inc. assumes no responsibility for use of contaminated refrigerant.
. 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). R404A is used in ice machines and reach-in freezers and R-134A is used in reach-in refrigerators. 1. What compressor oil does Manitowoc require for use with HFC refrigerants? Manitowoc products use Polyol Ester (POE) type compressor oil. It is the lubricant of choice among compressor manufacturers. 2.
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Attend A Manitowoc Factory Service School • 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 • Contact Your Distributor or Manitowoc Ice, Inc. for Details OR • Visit Our Website at www.manitowocice.com for School Dates MANITOWOC ICE, INC. 2110 South 26th Street P.O.
