User manual SCOTSMAN MCM1062

MCM1062R INTRODUCTION This manual is intended as a reference for the installation and service of a Scotsman ice maker model MCM1062. This model is a remote condenser cuber, 30" wide and may be connected to a Mac 6 or a Scotsman remote condenser. This ice machine uses R-22. TABLE OF CONTENTS Page Specifications For the Installer Machine & Bin Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 For the Plumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Remote Condenser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Coupling Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 For the Electrician . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Final Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Initial Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Component Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Service Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Removal and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 ...................................... 2 Environmental Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Parts lists and wiring diagrams are in the center of this manual, printed on yellow paper. October 1993 Page 1 MCM1062R SPECIFICATIONS Always refer to the nameplate, located on the back of the cabinet, for the: · model number, · serial number, · basic electrical requirements, · minimum circuit ampacity, · maximum fuse size, · and refrigerant charge. A serial number plate with the model number, serial number and refrigerant charge is located behind the front panel, near the control box. The unit comes from the factory with the correct refrigerant charge contained in the receiver. The refrigerant charge information is for recharging, should that be necessary. All utility connections and refrigerant line connections are made at the back of the ice maker. Before beginning installation, be sure that all of the components necessary for complete assembly of the ice system are available, and are the correct components with regard to model, voltage, and finish. Installer: After installation, take this manual with you, do NOT leave it with the machine. October 1993 Page 2 MCM1062R FOR THE INSTALLER: Environmental Limitations Installation Limitations The ice making portion of this ice system is designed to be installed indoors, in a controlled environment. Minimum Air Temp Water Temp Water Pressure Voltage 50 F. 400F. 20 PSI 197 0 Water Limitations An ice machine is a food manufacturing plant; it takes a raw material, water, and turns it into a food product, ice. The purity of the water is very important in obtaining pure ice and in maximizing product life. These general recommendations should help keep the ice maker clean: 1. Filter the water used to produce ice. Water filters vary greatly in ability and function. Install one that filters out suspended solids to a dimension of 5 microns or smaller. The finer the filter the better, but finer filters will clog sooner than course ones. It may be necessary to add a course filter ahead of the fine filter to prolong filter life. 2. Check with a water treatment specialist for a water test, and recommendations regarding filters and treatment. Service Limitations Some space on the sides, the back and the top should be allowed for service and utility connections. Maximum 1000F. 1000F. 80 PSI 253 Operating the ice machine outside of the above limitations, or outdoors, is potentially damaging to the machine; also it is misuse of the machine, which may void the warranty. Scotsman Ice Systems are designed and manufactured with the highest regard for safety and performance. They meet or exceed the standards of UL, NSF, and CSA. Scotsman assumes no liability or responsibility of any kind for products manufactured by Scotsman that have been altered in any way, including the use of any part and/or other components not specifically approved by Scotsman. Scotsman reserves the right to make design changes and/or improvements at any time. Specifications and design are subject to change without notice. NAMEPLATE, LOCATED ON BACK PANEL. A SERIAL NUMBER PLATE IS LOCATED BEHIND THE FRONT PANEL, NEAR THE CONTROL BOX. October 1993 Page 3 MCM1062R FOR THE INSTALLER: Machine & Bin Assembly Overview: This ice system is comprised of 4 major assemblies: 1. The ice storage bin. 2. The ice maker itself. 3. The interconnecting refrigerant lines. 4. The remote condenser. Additionally, there will be interconnecting wires between the ice maker and the condenser. The Scotsman remote condenser is powered from the ice maker. The condenser must be located above the ice maker, usually on the roof. Storage Bin: 1. Measure the location of the ice machine floor drain relative to the installed location of the bin. Route all drain lines so that when the machine is installed in its normal position, the drain tubes terminate just above the floor drain. 2. Using corner posts from the bin's carton as a cushion, lay the bin on its back. 3. Install the casters into the leg sockets. 4. Move bin back to an upright position. 5. Check that the back set of casters are in in line to allow the bin to be rolled back and forth. 7. Hang the scoop holder and scoop from the front edge of the bin (inside the bin). 8. Install the bin bumpers at the back of the bin. 9. Remove all material that is packed inside the bin. Ice Maker: 1. Arrange for proper electric, water and drain. See instructions for the plumber and for the electrician. 2. Position the ice storage bin in the selected location which should have a minimum room temperature of 50-degrees F. and maximum room temperature of 100 degrees F. 3. Inspect the bin top mounting gasket which should be flat, with no wrinkles, to provide a good water seal when the cuber is installed on top of the bin. 4. Install the modular cuber on top of the bin using care to be sure a good seal is made between the two cabinets, use of a mechanical lift is recommended. Align the holes in the bottom back of the cabinet to mate with the two mounting straps on the top rear of the bin. 5. Use bolts and straps found in the hardware package to secure the ice machine to the ice storage bin. Attach the bin bumpers to the bin with the bolt holding the mounting strap to the bin. When alignment and leveling are completed, tighten the bolts to secure the mounting straps. MOUNTING STRAPS AND BOLTS BIN BUMPER 5" October 1993 Page 4 MEASURE THIS DISTANCE FLOOR DRAIN MCM1062R FOR THE PLUMBER Water Supply The recommended water supply line is a 3/8-inch O.D. tubing with a minimum operating pressure of 20 PSIG and a maximum of 80 PSIG. Connect to cold water supply line with standard plumbing fittings, with shut off valve installed in an accessible place between the water supply and the cuber. ln some cases a plumber will be required. Drain Connections: Drain tubing and fittings are supplied with the ice bin. All drains are gravity type and must have a minimum of 1/4-inch fall per foot on horizontal runs. The drains to be installed must conform with the local plumbing code. Install a vertical open vent on the drain line(s) high point to ensure good draining. The ideal drain receptacle is a trapped and vented floor drain. October 1993 Page 5 MCM1062R FOR THE INSTALLER: Remote Condenser Scotsman Condenser: Locate the condenser as near as possible to the interior location of the ice maker. Location of the condenser is limited by the specific length of pre-charged refrigerant tubing supplied for the application. The pre-charged tubing connects the icemaker to the remote condenser. The condenser must be above the ice maker. Select the best available location, protecting the condenser from extremes of dirt, dust, and sun. Meet all applicable building codes. Roof Attachment: Install and attach the remote condenser unit to the roof of the building, using the methods and practices of construction that conform to the local building codes, including having a roofing contractor secure the condenser to the roof. FLEXIBLE TUBING END SCOTSMAN REMOTE CONDENSER PRE-CHARGED REFRIGERANT LINE SET October 1993 Page 6 MCM1062R FOR THE INSTALLER: Remote Condenser (Scotsman) Pre-charged Line Routing /////////////////////////////CAUTION/////////////////////////////// Do not connect pre-charged tubing until all routing and forming of the tubing is complete. See the coupling instructions for connecting instructions. //////////////////////////////////////////////////////////////////////////// 1. Each set of precharged refrigerant lines consists of a 3/8 inch diameter liquid line, and a 1/2 inch diameter discharge line. Both ends of each line have quick connect couplings, one end has flexible tubing: that end goes to the icemaker. Note: The openings in the building ceiling or wall, listed in the next step, are the minimum sizes recommended for passing the refrigerant lines through. 2. Have the roofing contractor cut a minimum hole for the refrigerant lines of 1.75". Check local codes, a separate hole may be required for the electrical power to the condenser. /////////////////////////////CAUTION//////////////////////////////// DO NOT KINK OR CRIMP REFRIGERANT TUBING WHEN INSTALLING IT. //////////////////////////////////////////////////////////////////////////// 3. Route the refrigerant lines through the roof opening. Follow straight line routing whenever possible. Any excess tubing MUST be retained within the building. 4. Spiral any excess length of pre charged tubing inside the building. Use a horizontal spiral (as illustrated) to avoid any traps in the lines. 5. Have the roofing contractor seal the holes in the roof per local codes. 6. The flexible line end must be installed behind the icemaker, it is to be looped down from the ice machine connection area then back up to the wall behind the ice machine. This allows the ice machine to be pulled out for service. REMOTE CONDENSER (SCOTSMAN) SPIRAL EXCESS TUBING HERE LOOP OF FLEXIBLE TUBING October 1993 Page 7 MCM1062R FOR THE INSTALLER: Remote Condenser (Mac 6) Precharged Line Routing ////////////////////////CAUTION/////////////////////////////// Do not connect precharged tubing until all routing and forming of the tubing is complete. See the coupling instructions for connecting instructions. /////////////////////////////////////////////////////////////////////// 1. Each set of precharged refrigerant lines consists of a 3/8 inch diameter liquid line, and a 1/2 inch diameter discharge line. Both ends of each line have quick connect couplings, one end has flexible tubing: that end goes to the icemaker. Note: The openings in the building ceiling or wall, listed in the next step, are the minimum sizes recommended for passing the refrigerant lines through. 2. Have the roofing contractor cut a minimum hole for the refrigerant lines of 1.75". Check local codes, a separate hole may be required for the electrical power to the condenser. ///////////////////////CAUTION//////////////////////////////// DO NOT KINK OR CRIMP REFRIGERANT TUBING WHEN INSTALLING IT. /////////////////////////////////////////////////////////////////////// 3. Route the refrigerant lines through the roof opening. Follow straight line routing whenever possible. Any excess tubing MUST be retained within the building. 4. Spiral any excess length of pre charged tubing inside the building. Use a horizontal spiral (as illustrated) to avoid any traps in the lines. 5. Have the roofing contractor seal the holes in the roof per local codes. 6. The flexible line end must be installed behind the icemaker, it is to be looped down from the ice machine connection area then back up to the wall behind the ice machine. This allows the ice machine to be pulled out for service. FLEXIBLE END LIQUID LINE ELECTRICAL CONNECTION MAC6 REMOTE UNIT October 1993 Page 8 MCM1062R FOR THE INSTALLER: Coupling Instructions /////////////////////////////CAUTION///////////////////////////// The couplings on the sets of precharged lines are self sealing when installed properly. Carefully follow the instructions: ////////////////////////////////////////////////////////////////////////// 1. Remove the protector caps and plugs. Wipe the seats and threaded surfaces with a clean cloth to be certain that no foreign matter remains on them. 2. Lubricate the inside of the couplings, especially the O-Rings with refrigerant oil. 4. Using a marker or pen, mark a line lengthwise from the coupling union nut to the bulkhead. Then tighten the coupling and additional 1/4 turn. As the nut turns, the line will show when 1/4 turn is made. 5. After all connections are made, and after the king valve has been opened, check the couplings for leaks. · The 3/8 inch liquid line (schrader valve end) goes to the remote condenser fitting marked "liquid line". · The other end of the liquid line goes to the icemaker fitting marked "liquid line." · The 1/2 inch discharge line (schrader valve end) goes to the remote condenser fitting marked "discharge line". · The other end of the discharge line goes to the icemaker fitting marked "discharge line". 3. Begin tightening the couplings together by hand, then using two wrenches (it is important that ONLY the nut on the precharged lines be turned, the other parts of the couplings must NOT be allowed to turn or the process will tear out the diaphragms and they will be loose in the refrigeration system) tighten the coupling until it bottoms out or a definite increase in resistance is felt. ONLY TURN NUT ON TUBING KIT, HOLD TUBING STATIONARY USE TWO WRENCHES October 1993 Page 9 MCM1062R FOR THE ELECTRICIAN: Electrical Connections See the NAMEPLATE for current requirements to determine wire size to be used for electrical hookup. The cuber requires a solid chassis to chassis earth ground wire. See Wiring Diagram. Be certain the cuber is connected to its own electrical circuit and individually fused. Voltage variation should not exceed ten percent of the nameplate rating, even under starting conditions. Low voltages can cause erratic operation and may be responsible for serious damage to the icemaker. Electrical connections are made at the rear of the icemaker, inside the junction box. /////////////////////////////CAUTION/////////////////////////////// Do not switch the ice maker on at this time, make certain the master and compressor switches are OFF when power is connected to the icemaker. Power must be connected to the ice maker long enough in advance of start up to allow the crankcase heater to warm the compressor, usually about 12 hours. ////////////////////////////////////////////////////////////////////////////// Scotsman Condenser: Separate electrical connections are made from the ice maker to the condenser, as there is line power interconnecting the icemaker to the condenser. All external wiring should conform to the national, state and local electrical code requirements. Usually an electrical permit and services of a licensed electrician will be required. REMOTE CONDENSER ELECTRICAL CONNECTION (SCOTSMAN CONDENSER) POWER SUPPLY TO REMOTE SCOTSMAN CONDENSER POWER SUPPLY TO ICE MAKER TERMINAL STRIPS October 1993 Page 10 MCM1062R FOR THE INSTALLER: Final Check List 1. Is the ice maker cabinet in a room where ambient temperatures are within the minimum and maximum temperatures specified? 2. Is there clearance at both sides of the cabinet and at the back and top for service and utility connections? 3. Has water supply pressure been checked to insure a minimum of 20 PSIG and a maximum of 80 PSIG operating pressure? 4. Is the cabinet level? 5. Check that any shipping material has been removed from inside the cabinet. 6. Have all electrical and piping connections been made? 7. Are the Master and Compressor switches on OFF? 8. Has power been connected to the ice maker? 9. Is the water supply line shut off valve installed? 10. Check all refrigerant lines and conduit lines, to guard against vibration or rubbing and possible failure. 11. Have the bin and cabinet been wiped clean and sanitized? 12. Has the Field Quality Audit form been properly filled out? Check for correct model and serial numbers from Serial nameplate, then mail the completed form to the SCOTSMAN factory. 13. Has the owner been given the name and telephone number of the authorized SCOTSMAN Service Agency serving him? POTABLE WATER INLET REMOTE CONDENSER (MAC 6) THE COMPLETED INSTALLATION SHOULD GENERALLY APPEAR AS ILLUSTRATED HERE EXCESS TUBING LOOPED HERE FLEXIBLE TUBING ELECTRICAL POWER TO CONDENSER ELECTRICAL POWER CORD DRAINS October 1993 Page 11 MCM1062R INITIAL START UP Remote Condenser: 1. Check that all connections have been made. Ice Maker: 1. Remove front panel by pulling out to unsnap. 2. Remove two screws and the control box cover. 3. Remove the evaporator cover. 4. Remove the left side service panel. 5. Check that the ON/WASH/OFF rocker switch and the Compressor ON-OFF toggle switch are in the OFF position, on the control box. 6. Locate and open the king (service) valve on the receiver. Check that the crankcase heater has "KING" been on long enough to warm the compressor VALVE dome (about 12 hours). 7. OPEN the water supply line shut off valve. 8. Inside the control box is the shaft of the timer and the switch assembly. Rotate the shaft of the timer and switch assembly clockwise to where the actuator arm on the microswitch drops off outer cam into cam slot. See Timer Cam Positions. 8. Move the ON/WASH/OFF rocker switch to the ON position. EVAPORATOR COVER ON/WASH/OFF SWITCH 9. Observe water fill cycle: The water inlet solenoid valve OPENS,and water flows from the valve to the reservoir. The reservoir fills and excess water drains out the machine drain. At the end of the harvest cycle, the water inlet solenoid valve will close and the water fill cycle is complete. If the reservoir is not full, advance the shaft of the timer clockwise into a new harvest cycle; this opens the water valve again. The water pump will be pumping water over the evaporators. 10. Check that the water cascades down over each cube mold and into the reservoir. 11. When the reservoir is full, move the compressor ON-OFF toggle switch, to the ON position. 12. Check operation of the freezing cycle: Ice begins to form from the top of the evaporator down. Freezing time will range between 13 and 15 minutes. Longer time for temperatures above 70 degrees F. and shorter time required when temperatures are below 70-degrees F. Average complete cycle time is about 16 minutes. 13. Check CUBE SIZE The dimensions of the cubes are fixed by the size and shape of the molds on the evaporator plate, except that the thickness of the cube MAY need to be adjusted at start up. There is only one size of cube that is correct; adjusting the cube size control to that size of cube will allow the ice maker to produce ice at its most efficient size. The correct size cubes will appear similar to the illustration for "Correct Size Cube". TIMER CAM POSITIONS ACTUATOR MICROSWITCH CAM & SHAFT HARVEST PORTION FREEZE PORTION October 1993 Page 12 MCM1062R INITIAL START UP Adjust for the correct size if needed: Locate cube size control knob in the front of the control box. Rotate this knob one eighth of a turn CUBES (ACTUAL SIZE) · Counter clockwise to produce SMALLER sized ice cubes or · Clockwise to produce LARGER ice cubes Observe size of the ice cubes in the next ice cube harvest and adjust again if needed, until the correct ice cube is achieved. 14. Check Harvest Time. The harvest time is determined by the gap in the timer cam. That gap may be adjusted if needed. The correct harvest time is when there are about 15 seconds of time left in the harvest cycle after the last cube has fallen from the evaporators. See the next page for detailed adjustment instructions. Do not adjust harvest time TOO SHORT or the machine will not harvest all the ice. 15. Check ICE BIN LEVEL CONTROL The amount of ice maintained in the bin is adjustable. The normal setting is "full". If the operator desires, the level of ice in the bin may be adjusted lower to shut off the machine when the bin is only partially full. The ice bin level control is designed for the MDB550 ice storage bin, use of other bins may result in ice levels that are more or less than the settings on the control indicate. To Test The Ice Level Setting: 1. Open the bin door and locate on the bottom of the ice machine, the ice level sensor. It's in a socket about 2" in diameter and located left of the evaporator plates. 2. When the machine is running, wait untIl near the end of a "harvest" cycle. 3. Hold a flat object about the size of this service manual over the ice level sensor socket. 4. The ice machine should turn off at the end of the harvest cycle. 5. Slowly lower the flat object straight down. 6. The ice machine will start again at the point where it will maintain the ice level. Adjust Bin Ice Level 1. Locate ice level control switch. 2. Move switch to the desired position. TOO THICK 1 1/4" CORRECT 1 1/4" SIZE CUBE Note:Optimum perfromance will be achieved when the ice machine is adjusted to porduce this size and shape of cube. The typical batch weight at this setting is between 8.25 and 9 pounds. TOO THIN 3. To test, wait until the ice machine is near the end of a "harvest" cycle, if there is ice in the bin higher than the position the ice level control is set for, the ice machine will turn OFF at the end of the harvest cycle. If no ice in the bin, test again as described under, "To Test The Ice Level Setting". 16. Replace all panels & covers. 17. Fill out and mail in the Customer Evaluation and Warranty Registration form. Inform the user how to call for service and the maintinance requirements of the machine. October 1993 Page 13 MCM1062R ADJUSTMENTS Adjustment Of The Timer & Switch Assembly TIMER CAM POSITIONS ACTUATOR MICROSWITCH CAM & SHAFT One complete revolution of the cam on the timer represents eight minutes. If left as factory set, four and one-half minutes comprise the freezing cycle portion during cam rotation, and the final three and one-half minutes is the defrost/harvest cycle. Rotating the shaft of the timer cam clockwise will put the ice machine in the freeze or harvest cycle. ////////////////////////////// WARNING /////////////////////////////// Disconnect electrical power supply to icemaker whenever adjustment procedures are performed. /////////////////////////////////////////////////////////////////////////////// To adjust the timer & switch assembly: HARVEST PORTION 1. Remove front panel. 2. Remove control box cover. A. To start the HARVEST CYCLE: Slowly rotate the shaft of the timer and switch assembly clockwise until the actuator arm on the microswitch begins the harvest cycle. An audible click can be heard, but in a noisy area, look at the cam and switch to observe the event B. To start the FREEZING CYCLE: Slowly rotate the shaft of the timer and switch assembly clockwise, until the actuator arm on the microswitch starts the freezing cycle. C. To adjust the length of the harvest cycle: FREEZE PORTION TIMER ADJUSTMENT MICROSWITCH SHAFT OF CAM 1. Loosen the adjustment screw on the cam, and rotate the shaft of the cam to move the top part of the assembly. More of a gap between the high and low portions will yield more harvest time. 2. Tighten the set screw. 3. Replace the control box cover and front panel. lt is important that the length of the harvest cycle allow enough time for all the ice cubes to fall from the evaporator. Too short of a time will cause the evaporator to freeze up and stop ejecting ice into the bin. Too much time wastes icemaking capacity, energy and water. Adjustment of the harvest cycle may require an adjustment of the cube size control. SET SCREW October 1993 Page 14 MCM1062R COMPONENT DESCRIPTION Compressor Contactor The compressor contactor carries the compressor line current. The contactor is wired so any control in the pilot circuit, such as the bin control, and high pressure controls, etc., will cause the contactor holding coil to be de energized, when the control contact OPENS, thereby breaking the circuit to the compressor. Cube Size Control This reverse acting (closes on temperature fall) thermostat determines how long the freezing cycle will be. The cube size control closes its contacts when the evaporator cools to the set temperature, starting the timer. A variation in heat load (either ambient air or incoming water temperature) will affect the efficiency of the refrigeration system, and that will vary the length of time it takes the evaporators to cool to the temperature at which the cube size control is set to close, which, in turn, will affect the overall cycle time. See CUBE SIZE ADJUSTMENT BEFORE attempting to adjust the control. Relay The multi-function, three pole, double throw, relay plugs into a socket on the printed circuit board in the control box. The relay functions in part to by-pass the bin control during the harvest and freeze cycles, preventing the icemaker from shutting off in the middle of a cycle. The bypass action allows only complete freeze and harvest cycles; the only time that the ice maker can shut off on bin control is as the end of the harvest cycle. Timer - Timer & Switch Assembly The timer begins to turn when activated by the cube size control. The outer surface, or large diameter lobe of the timer cam, determines the length of time for finish freezing of the ice cubes, while the inner surface, or small diameter lobe, determines length of the harvest cycle. The single-pole, double throw microswitch on the timer controls the power to the plug in relay coil, making it either the freezing or harvest cycle. The microswitch is actuated by a cam assembly directly connected to the timer motor. The timer cam can be adjusted to vary the defrost time, as required. One complete rotation of the cam will take eight minutes. Harvest is preset at 2 and a quarter minutes. Hot Gas Solenoid Valve The hot gas solenoid valve opens only during the harvest cycle. When it opens, it diverts the hot discharge gases so that they flow directly into the evaporator plates, by-passing the condenser and thermostatic expansion valve. The hot gases warm the evaporators, releasing the ice cubes from the ice cube molds. The hot gas solenoid valve is installed in a branch of the discharge line from the compressor, and when the timer switches the ice machine into the harvest cycle, the energized solenoid coil lifts the valve stem within the valve body, allowing the hot discharge gas to be diverted to the evaporators. High Temperature Cut Out This temperature sensor is located next to the hot gas valve, on the outlet side. During normal operation, it does not affect the ice machine, but it will shut the machine off if the hot gas line overheats. It is an automatic reset. October 1993 Page 15 MCM1062R COMPONENT DESCRIPTION Ice Level Control This electronic control uses sound waves to measure the distance between the bottom of the ice machine and the top of the ice in the bin. It is designed to control the machines ice production to maintain that distance. The control is adjustable so that the ice machine will maintain a certain height of ice. It will not fill any closer to the ice machine than 8", and will not work if the distance to the bottom of the bin is greater than 8 feet. Because it uses sound waves, a slight "ticking" sound can be heard coming from the bottom of the machine. ON/OFF/WASH SWITCH ICE LEVEL SELECTOR SWITCH THE USER CAN SELECT THE AMOUNT OF ICE TO BE MAINTAINED IN THE BIN. SOUND WAVES FULL 3/4 1/2 1/4 October 1993 Page 16 MCM1062R COMPONENT DESCRIPTION Electric Water Inlet Valve The water inlet solenoid valve fills the reservoir assembly with water. Excess water overflows out the overflow standpipe located at the back of the reservoir. This action fills and rinses the reservoir during each harvest cycle. The flow rate is .75 g.p.m. Water Distribution System The water distribution system evenly supplies water to all cells of the evaporator plates. The water pump pumps water from the reservoir up the vertical tygon tube to the tee. From there water is channeled through the water manifold to the water distributors, above each evaporator plate, and from six holes within each distributor, water flows to the cells of each side of the evaporator plates. Gravity flow returns the unfrozen excess portion of water to the reservoir for recirculation. Reservoir The reservoir, located below the evaporators, stores the inlet water charge, and collects the water that flows over the evaporator plates. Strainer A water strainer is located in the potable inlet water line before the water inlet solenoid valve. Clean the water strainer as needed. High Pressure Safety Control This is a manual reset control that shuts down the icemaker, should the discharge pressure ever reach 400 PSIG. WATER DISTRIBUTION SYSTEM EVAPORATOR WATER PUMP RESERVOIR HIGH PRESSURE CUT OUT STRAINER ELECTRIC WATER VALVE October 1993 Page 17 MCM1062R SERVICE SPECIFICATIONS When servicing a machine, it's helpful to compare that unit's operating characteristics to those of a new, clean, normally operating machine. What follows is that type of information: COMPONENTS Timer: Makes one complete revolution in 8 minutes. The harvest time is factory preset at 2 1/4 minutes. The harvest time is adjustable as required. Inlet Water Valve: Opens and admits 3/4 gallon per minute during the harvest cycle. Cube Size Control: Reverse acting temperature control, contacts close between 240F. and 00F. Typically adjusted to close at 130F. Pump Down Control: Contacts open at 20 P.S.I.G. and close at 35 P.S.I.G. High Pressure Safety Switch: Contacts open at 400 P.S.I.G. Bin or Ice Level Control Maximum Full Height 8" from the base of the ice machine. Partial Setting 21" - 22" from the base of the ice machine. Maximum Storage Bin Interior Height 8' from the base of the ice machine. OPERATING CHARACTERISTICS The values listed below are representative of values seen at a wide range of air and water temperatures and are for a normal cube size. Temperatures are Condenser/ Ambient Air/ Water FREEZE CYCLE Average Discharge Pressure at Average Temp. Suction pressure at the end of the freeze cycle Freeze Time 275-210 P.S.I.G. 24-20 P.S.I.G. 15-17 minutes HARVEST CYCLE Average Discharge Pressure 175 P.S.I.G. Average Suction Pressure Lo Temp (0/70/55) 75-80 P.S.I.G. Average Temp (90/90/70) 80-90 P.S.I.G. High Temp (110/90/80) 90-100 P.S.I.G. Harvest time is assumed to be 2.25 minutes. This can be adjusted to suit local conditions. This unit uses R-22. The system charge is 256 ounces. If the nameplate lists a different quantity of refrigerant, go by the nameplate. October 1993 Page 18 MCM1062R CLEANING /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// A Scotsman Ice System represents a sizable investment of time and money in any company's business. In order to receive the best return for that investment, it MUST receive periodic maintenance. Maintenance and Cleaning should be scheduled at a minimum of twice per year. ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// 9. Switch the machine to "wash" and continue to CLEANING: ICEMAKER add fresh water to flush residual cleaner from the ///////////////////////////////WARNING///////////////////////////// system. Switch the Wash/Off/Ice switch off. Electrical power needs to be on when doing in 10. Sanitize the ice maker and bin, see "Sanitize place cleaning. Water System". ///////////////////////////////////////////////////////////////////////////// 11. Replace the front liner. 1. Remove front panel. 12. Switch the Wash/Off/Ice switch back on. 2. Switch the Wash/Off/Ice switch to OFF. 13. Replace the front panel 3. Remove the front liner. 14. Check the next batch of cubes to make sure all 4. Remove and discard all ice from the storage bin. of the acid taste is gone. 5. Locate the reservoir drain cap, remove the cap /////////////////////////////////CAUTION////////////////////////////// and drain the reservoir. Replace the drain cap. If DO NOT use ice produced from the cleaning the reservoir doesn't drain completely, disconnect solution. Be sure none remains in the bin. the pump hose attached to the water distributors and place the end of the hose in a bucket. Switch //////////////////////////////////////////////////////////////////////////////// the Wash/Off/Ice switch to Wash, and allow the 15. Remove and discard all ice from the storage pump to discharge the rest of the water. Reattach bin, pour hot water into the storage bin to melt the the hose to the water distributors. cubes and also clean out the bin drain. 6. Mix 8 ounces of Scotsman Ice Machine Cleaner Scotsman Ice Machine Cleaner contains acids. These compounds may cause burns. If swallowed, DO NOT induce vomiting. Give large amounts of water or milk. Call Physician immediately. In case of external contact, flush with water. KEEP OUT OF THE REACH OF CHILDREN. with 1 gallon of warm (950F. - 1150F.) water and pour into the reservoir until full. 7. Switch the Wash/Off/Ice switch to "wash". Let the unit operate for 30 minutes, then switch the unit off. 8. Drain the reservoir again (repeat step 5). 16. The unit is now ready for continued automatic operation. Strainer: A water strainer is located in the water line before the inlet water solenoid valve. It is designed to catch large particles that may be in the water. To clean: 1. Shut off water supply. 2. Unscrew screen from strainer. 3. Brush particles from screen 4. Replace screen in strainer. 5. Turn water supply back on. SCREEN October 1993 Page 19 MCM1062R CLEANING SANITIZE WATER SYSTEM 1. Remove and discard all ice from the bin. 2. Remove front panel. 3. Drain the reservoir 4. Prepare 2 gallons of an approved sanitizer solution in accordance with the instructions on the package. 5. Pour 1 gallon of the sanitizer into the ice maker reservoir. 6. Move the main switch to "Wash", and allow the solution to circulate for a MINIMUM of 5 minutes. 7. Move the main switch to "Off". 8. Pull out the drain plug and drain the reservoir. 9. Using a clean sponge and the remainder of the sanitizer solution, wipe the interior of the evaporator cover and the inside of the storage bin, taking care to wipe all surfaces that are normally in contact with ice. 10. Replace the evaporator cover. Replace the front panel. 11. Move the master switch to ON. SCOTSMAN REMOTE CONDENSER 1. Disconnect electrical power at the icemaker. ///////////////////////////////WARNING/////////////////////////// Disconnect electrical power before beginning. //////////////////////////////////////////////////////////////////////////// 2. Wipe off any surface dust from the intake side of the condenser. 3. Vacuum the coil, or clean with coil cleaner. 4. The coil is clean when light can be seen through the fins. 5. Reconnect electrical power. SANITIZE ICE STORAGE BIN This procedure is to be done monthly 1. Remove and discard all ice from the bin. 2. Switch the ice maker off. 2. Prepare 2 gallons of an approved sanitizer solution in accordance with the instructions on the package. 3. Using a clean sponge wipe the inside of the storage bin and door, taking care to wipe all surfaces. 4. Rinse the interior of the storage bin using clean water and the sponge used in step 3. 5. Switch the ice machine back on. RESERVOIR DRAIN ON/OFF/WASH SWITCH October 1993 Page 20 MCM1062R FREEZING CYCLE OPERATION Water from the sump assembly is pumped to the water distributor system at the top of each evaporator plate. From the water distributor the water cascades by gravity over all cells of the plate and to the sump assembly below. At the beginning of the freezing cycle, the electrical circuit is completed to the compressor and the water pump. The water pump operates continuously, through both the freezing cycle and the harvest cycle. During the freezing cycle, the hot gas solenoid valve is CLOSED and the water inlet solenoid valve is CLOSED. When the ice cubes are partially formed, the cube size control will sense the temperature at which it is preset to CLOSE. This will complete the electrical circuit to the timer. The timer then controls the remainder of the freezing cycle. The timer will keep the icemaker operating in the freezing cycle for a selected length of time. This will give the ice cubes time to fully form. after that selected length of time, the timer will switch the icemaker into the harvest cycle, through the contacts of the timer assembly microswitch. Low Temperature Freeze: When the outside air temperature is low, the Head Pressure Regulator will close off the liquid line to the receiver, causing liquid refrigerant to back up into the condenser unitl the head pressure builds up to 220 PSIG. While this is occuring, the head pressure regulator passes discharge gas into the receiver to keep the refrigerant flowing. October 1993 Page 21 MCM1062R HARVEST CYCLE - HOT GAS BYPASS When the timer switches the icemaker into the harvest cycle, high pressure, high temperature gas refrigerant being discharged from the compressor is diverted from the condenser through the hot gas solenoid valve into each evaporator plate. During this cycle, the refrigerant bypasses the condenser. ln the electrical circuit, both the compressor and the water pump are operating and the hot gas solenoid valve is energized and OPEN and the water inlet solenoid valve is OPEN. The finished ice cubes are released from the sides of each evaporator plate by the warming effect of the hot gas condensing in each evaporator plate and the water cascading over the ice cubes. The released ice cubes drop into the ice storage bin below. At the end of the harvest cycle, the timer cam will push the actuator arm to the microswitch IN. If the ice level control is still CLOSED, a whole new cycle will begin. If the ice level control is OPEN, the icemaker will begin to shut OFF. Pump Down Cycle: When the ice level control is open at the end of the harvest cycle, power is removed from the liquid line valve coil, and the pump down cycle begins. The compressor will continue to run until the pump down control, sensing low side pressure, opens at 20 PSIG. October 1993 Page 22 MCM1062R SERVICE DIAGNOSIS SYMPTOM No ice, machine does not run POSSIBLE CAUSE 1. No electrical power 2. Circuit breaker tripped or fuse blown 3. High pressure control open. PROBABLE CORRECTION 1. Restore power 2. Reset breaker or replace fuse, check for electrical fault. 3. Reset HPC, check fan motor for proper operation, and condenser coil for dirt. 4. Check ice level control circuit. See page 25. 5. Hot gas valve leaks thru, replace hot gas valve 6. Replace timer 7. Check or replace switch. 8. Replace circuit board. 1. Check or replace switch 2. Replace contactor 3. Check electrical connections to liquid line valve, check coil, check valve operation 4. Defective switch, or liquid line valve does not open, or low on refrigerant; check/replace 5. Check/replace TXV. 1. Check/replace water pump 2. Check/replace water inlet valve. 1. Check for slow leak thru of water inlet valve. 2. Check pressures, if low find/repair leak. weigh in charge. 3. Defective compressor - replace 1. Check condenser air inlet and water temperatures. 2. Replace compressor 3. Check head pressure, if very high, and no other reason is suspected, replace refrigerant charge. 4. Bin level control holding machine off 5. High temp. cut out open 6. Timer switch open 7. On/Off switch open 8. Circuit board open No ice, compressor does not run, rest of ice machine does. 1. Compressor on/off switch open 2. Open contactor coil 3. Liquid line valve does not open 4. Pump down pressure switch does not close 5. Thermostatic Expansion valve clogged or does not open. No ice, no water over evaporators No ice, everything runs 1. Water pump does not pump 2. No water in reservoir 1. Too much heat load 2. Low on refrigerant 3. Suction pressure too high Low ice production 1. Too much heat load. 2. Compressor inefficient. 3. Non condensable gasses in refrigeration system. October 1993 Page 23 MCM1062R SERVICE DIAGNOSIS SYMPTOM Low ice production POSSIBLE CAUSE 3. High head pressure, a result of a dirty condenser 4. Hot gas valve leaks thru 5. High air temp. for condenser. PROBABLE CORRECTION 3. Clean condenser, check fan motor 4. Replace hot gas valve 5. If possible, reduce condenser air inlet temperature. 1. Check temp. of suction line, cube size control will not close if temp. too high. If temp. low enough, replace cube size control 2. Replace timer 3. Replace relay 4. Adjust timer for more harvest time 5. Adjust cube size 6. Replace hot gas valve. 7. Check for restriction of water supply. 8. Check pressure control valve. Check for low refrigerant charge. 1. Replace relay 2. Check for power to timer motor, if power replace timer, if no power to timer motor, replace relay. 3. Replace timer. 1. Check for restriction of water supply. Check for leak. 2. Clean ice maker. 3. Adjust cube size control 1. Repair drain 2. Replace valve No ice falling in bin, unit frozen up 1. Cube size control will not close 2. Timer motor open 3. Plug in relay contacts open 4. Not enough time during the harvest cycle to drop all ice 5. Cube size wrong 6. Hot gas valve restricted. 7. Not enough water to help harvest. 8. Head pressure too low Ice maker stuck in harvest cycle 1. Relay coil open 2. Timer stuck in harvest cycle 3. Timer microswitch N.O. contacts will not close. Ice is mal-formed 1. Shortage of water 2. Evaporator water passages restricted. 3. Cube size set wrong Water overflows from reservoir into bin. 1. Restricted sump drain 2. Inlet water valve lets in too much water October 1993 Page 24 MCM1062R SERVICE DIAGNOSIS: Ice Level Control Circuit CONDITION Ice Machine does not run, it has power to it, the high pressure control is closed, the on/off switch is set to ON (the compressor will not operate until the liquid line valve opens, but the pump should be working if there is no ice in the bin). DETERMINE CAUSE A. Listen for a ticking sound from transducer. PROBABLE CORRECTION If no noise, go to C. If there is a noise, check for a light on the board (models built after 4/93). If there is a light on, check relay contacts N.O. and COM. The contacts should be CLOSED. If closed, go to D. If not, replace the board. If light is off, or prior model, go to B. If the inside of the transducer (above screen) was wet, replace it. Set bin level to FULL and aim at an object about 1-3 feet away. Machine should restart, if not go to D. Should be 12 volts from transformer, if not replace transformer. If there is power go to D. If machine does not start go back to machine circuit. If machine starts, disconnect electrical power, remove jumper wire and reconnect electrical power. Then go to E. B. Open bin door and twist transducer 1/4 turn and pull out. DO NOT UNPLUG with power connected. Examine the transducer, the inside must be clean and dry. C. Check power to bin level control board. D. Disconnect electrical power and test ice machine circuit by attaching a jumper wire between bin thermostat posts on circuit board part no. 12-1912-01 (the circuit board with the timer on it). Reconnect power. E. Transducer or ice level board assembly defective. Replace transducer. Set bin level to FULL and aim at an object about 1-3 feet away. Machine should restart. If this does not repair unit, replace the board. Replace ice level switch Machine runs, makes ice, switches on and off, but ice level cannot be controlled. Machine runs, but will not shut off. Ice level switch may be defective. On boards with a light, check by moving switch & watching light. Board relay stuck closed. Check relay. If COM and N.O. are closed when power is off, replace board. If open, go to B above. PARTIAL VIEW OF CIRCUIT BOARD 12-1912-01 PLUG - IN RELAY TIMER BIN THERMOSTAT October 1993 Page 25 Electrical Shock Hazard Can Cause Personal Injury. Disconnect Power Before Servicing. POSTS Bin Thermostat Posts at Line MENTIONED IN "D" ABOVE Voltage. MCM1062R REMOVAL AND REPLACEMENT TRANSDUCER 1. Disconnect electrical power BEFORE removing transducer. 2. Open bin door and locate the transducer socket. 3. Twist inner portion of transducer counterclockwise and push up gently. 4. Pull transponder down until plug connection is accessible. 5. Unplug transducer and remove from the machine. 6. Reverse steps 1-5 to reassemble. TRANSDUCER LOCATION TRANSDUCER SOCKET TRANSDUCER PLUG CONNECTION REMOVAL OF TRANSDUCER October 1993 Page 26 MCM1062R REMOVAL AND REPLACEMENT /////////////////////////////////WARNING////////////////////////////// Disconnect electrical power before beginning. ///////////////////////////////////////////////////////////////////////////////// Water Distributor Tubes And Manifold Tubes To remove the water distributor tube and manifold tube: 1. Pull out to unsnap catches and remove the front panel. 2. Remove the evaporator cover. 3. Slide the water distributor tube to the front about 1/8-inch along the top of the evaporator plate, until the water distributor tube can be unsnapped from the flexible notch and lifted upward to the right side. 4. Unsnap and disconnect water distributor tubes from the water manifold section. To replace the water distributor tubes and manifold tubes, reverse the removal procedure. BE SURE the notches in the water manifold tubes properly engage the alignment keys in the tee. BE SURE the water distributor tube is securely fastened at the notch at both sides of the evaporator plate. Check identical attachment for the left water distributor tube and notch; also, that the distributor/manifold connections at the top center of each evaporator plate is snug against the top of the plate. Cube Size Control To remove the cube size control: 1. Remove front panel. 2. Remove cover from control box. 3. Trace capillary tube, from the cube size control to the refrigerant suction line. 4. Remove the coiled capillary tube bulb from the tube well on the suction line. 5. Remove electrical leads from the cube size control. 6. Remove screws and the cube size control. To replace the cube size control, reverse the removal procedure. Be certain that the bulb is re-insulated. WATER DISTRIBUTOR TUBES CUBE SIZE CONTROL October 1993 Page 27 INLET WATER VALVE MCM1062R REMOVAL AND REPLACEMENT //////////////////////////////WARNING////////////////////////////////// Disconnect electrical power before beginning. ////////////////////////////////////////////////////////////////////////////////// Water Pump 1. Remove front panel. 2. Remove evaporator cover. 3. Unplug water pump electrical connection. ELECTRICAL CONNECTION Inlet Water Solenoid Valve Assembly To remove the inlet water solenoid valve assembly: 1. Shut OFF water supply to machine. 2. Loosen and remove outlet water line from the inlet water solenoid valve assembly. 3. Remove screws and pull the water solenoid valve out to gain access. ELECTRICAL CORD INLET WATER SOLENOID OUTLET TUBE WATER PUMP DISCHARGE HOSE REMOVAL OF THE WATER PUMP REMOVAL OF INLET WATER SOLENOID VALVE 4. Remove thumb screw retaining pump to cross brace. 5. Pull pump partially out of reservoir and remove discharge hose. 6. Remove two nuts holding pump cover to pump body; separate the two and remove the pump from the icemaker. 7. Reverse to reassemble. 8. Replace all panels. 9. Reconnect electrical power. 4. Pull electrical cord from solenoid coil terminals. 5. Remove inlet water fitting from the water solenoid valve. To replace the inlet water valve assembly, reverse the removal procedures. October 1993 Page 28 MCM1062R REMOVAL AND REPLACEMENT Head Pressure Control Valve 1. Remove side service panel, and top panel if possible. 2. Discharge and recover refrigerant from the system. 3. Break off the process tube on the dome of the head pressure control valve. 4. Cut out or unsweat the tubing connections to the valve. Remove the valve. 5. Wrap the new valve in wet cloths or other effective heat sink material, and sweat the tubing connections to the valve. 6. Weigh the nameplate charge into the receiver. 7. Replace all panels. 8. Reconnect electrical power. Hot Gas Valve or Liquid Line Valve 1. Remove the side service panel, and top panel if possible. 2. Discharge and recover the refrigerant from the system. 3. Remove the electrical connections from the coil of the valve 4. Cut out or unsweat the valve at the tubing connections, remove the valve from the icemaker. 5. Install the new valve, wrap it in wet cloths or other efficient heat sink material. 6. Sweat the tubing connections to the valve. 7. Connect the electrical wires to the terminals of the valve coil. 8. Weigh the nameplate charge into the receiver. 9. Replace all panels removed for service. 10. Reconnect electrical power. Thermostatic Expansion Valve 1. Remove the side service panel, and top panel if possible.. 2. Discharge and recover the refrigerant from the system. Reclaim it if possible. 3. Locate the TXV sensing bulb on the suction line, unwrap the insulation and remove the bulb from the clamp. 4. Cut out or unsweat the old TXV from the tubing connections. 5. Wrap the new TXV body in wet cloths or other efficient heat sink material. 6. Re-attach the TXV bulb to the suction line in the same place as the original. Be certain to re-insulate the bulb. 7. Sweat in the new valve. Do not overheat. 8. Weigh the nameplate charge into the receiver. 9. Replace all panels removed for service. 10. Reconnect electrical power. October 1993 Page 29