Service Manual - CME250

Introduction CME250To the owner or user: This service manual is The refrigeration system uses HP62 as theintended to provide you, and the maintenance or refrigerant. HP62 models use polyolesterservice technician, with the information needed to refrigerant oil.install, start up, clean, maintain and repair this Information on HP62 is located on page 23.product.The CME250 is an ice machine that producescubed ice on 2 vertical cube freezing surfaces. Thecubes fall as vertical strips of cubes into the icestorage bin where they break up into individualcubes. The CME250 automatically maintains thelevel of ice by turning on when the ice level falls,and switches off when the bin is full. Table of ContentsSpecifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 2Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 3Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 4Plumbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 6Final Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 8Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 9Initial Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 11Electrical Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 12Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 13Water/ Refrigeration Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 16Technical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 18Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 19Removal and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 21Refrigeration Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 23Parts lists and wiring diagrams are located in thecenter of this manual, printed on yellow paper.Note the warning symbol where it appears in thismanual. It is an alert for important safetyinformation on a hazard that might cause seriousinjury.Keep this manual for future reference.This manual was printed on recycled paper. August 1994 Page 1

CME250 Nameplate Serial Number PlateSpecificationsInformation regarding Model Number, SerialNumber, Ampacity and Maximum Fuse Size arelocated on the nameplate of the ice machine. Themodel number, serial number and refrigerantcharge are also listed onthe serial number platejust behind the frontpanel.If recharging, alwaysuse the charge listed onthe ice machine. The CME250 will stack ontCoMaEv2a5r0ietCyaobfinSetcotsman ice storage bins: •*BH550 •*HTB500, HTB350, HTB250 •BH800 (with bin top KBT23) •BH900 (with bin top KBT22) •BH1360 It will also fit these Scotsman Dispensers: •CD200 •IS150 (with KADCM1) •RS150 (with KADCM1) * These smaller bins are recommended. There is an optional stainless steel panel kit, SPKCMD-1, for this machine.Specifications:Model Number Dimensions Condenser Basic Minimum Maximum Fuse Refrigerant W\" x D\" x H\" Size (or HACR Charge. HP62 Type Electrical Circuit circuit breakers)CME250AE-1E 30 x 24 x 27CME250WE-1E 30 x 24 x 27 Ampacity 20 27 ounces Air 115/60/1 16 20 17 ounces Water 115/60/1 16 October 1994 Page 2

CME250For The Installer: Environmental LimitationsThe ice machine must be installed indoors in acontrolled environment.Air Temp Minimum MaximumWater Temp 500F. 1000F. 400F. 1000F.Water Pressure 20 PSI 80 PSIVoltage 103.5 126.5Operating the ice machine outside of the abovelimitations, or outdoors, is potentially damaging tothe machine, and it is misuse of the machine. Thismay void the warranty.Scotsman Ice Systems are designed andmanufactured with the highest regard for safetyand performance. They meet or exceed thestandards of UL, NSF, and CSA.Scotsman assumes no liability or responsibility ofany kind for products manufactured by Scotsmanthat have been altered in any way, including theuse of any part and/or other components notspecifically approved by Scotsman.Scotsman reserves the right to make designchanges and/or improvements at any time.Specifications and design are subject to changewithout notice.Airflow on air cooled models is: •Intake through the right side grill. •Exhaust through the left side grill.Do not install where this air flow is obstructed. 6inch clearance is required at the sides and back. August 1994 Page 3

CME250 Air cooled models blow air in and out through the grills at the sides (in the right and out the left).Installation Space is required for air flow at the sides and utility connections at the back.WaterThe water supply for this ice machine has been in The ice machine is not designed for outdoorcontact with many materials since it fell from the use. It must be installed indoors, in asky as rain. All rain is slightly acidic, and tends to controlled environment. The air and waterdissolve the materials it comes in contact with. temperatures must not exceed rated limits.During water’s journey to the ice machine, it hasflowed over and through the ground, been picked Pre-installation:up by a municipal or private pump, forced through 1. Inspect the place where the ice machine is to bea series of pipes of differing construction and may installed. Check for:have been treated by the municipality providingthe water. •space for the cabinet, •water supply,The water supplied to this ice machine will then •drain availabilitycontain a variety of substances that will likely show •and electrical power supply.up as solids during the ice making process. Thesesolids are similar to those found when water is No extension cords are allowed. The building drainboiled out of a saucepan. Only the water boils inlet must be lower than the drain outlet of the iceaway, and the minerals that were in the water bin. The water supply must have a hand shut offsolidify in the pan. During ice making only the valve accessible when the unit is installed.water is frozen into ice, the minerals stay behind inthe reservoir. This machine pumps out the water inthe reservoir every cycle to minimize the amount ofminerals in the water system, but after time theminerals will appear and have to be dissolved byice machine cleaner, then flushed away during thecleaning process.An ice machine is a food manufacturing plant; ittakes a raw material, in this case water, andtransforms it into a food product, ice. The purity ofthe water is very important in obtaining pure iceand in maximizing product life.The water to the ice machine should be filtered.Water filters vary greatly in ability and function.Install one that filters out suspended solids to adimension of 5 microns or less. The finer the filterthe better, but finer filters may plug-up sooner thancourse ones. It may be necessary to add a coursefilter ahead of the fine filter to prolong filter life.Have the water tested. Acidic water or alkalinewater will both cause corrosion. Dissolved solidscannot be filtered out. Check with a watertreatment specialist regarding testing, treatmentand filters.October 1994 Page 4

Installation CME250Assembly: Bin Thermostat Installation1. Attach the legs, or optional casters, onto the icestorage bin. Units that are stacked should only use Thermostatlegs, not casters. Capillary Tube2. Place the ice machine onto the storage bin. Bin Thermostat Bracket3. Line up the ice machine, check that there is agood seal between the ice machine and the Stackingstorage bin. Strap Capillary Tube4. If on a Scotsman bin, attach the ice machine to Routing Holethe bin using the straps and bolts shipped with theice machine. If on another brand bin, follow the Reservoirdirections included with that bin. Bin Thermostat BracketBin Thermostat Installation:1. Remove rubber cap from the end of thethermostat bracket.2. Attach the bin thermostat bracket to the bottomof the ice machine using the thumb screwsprovided. There are pre-drilled and tapped holeslocated just behind the cube drop area. The end ofthe bin thermostat bracket with the plastic tubingon it will fit into the hole in the base of the machine.3. Locate and uncoil a portion of the bin thermostatcapillary tube. Route the end of the capillary tubeinto and through the bin thermostat bracket tube. Itshould be inserted the full length of the tube, butnot past the end.Stacking:This machine will stack onto any CME250,CME250, CM450, CM500, CME500, CM650 orCME650 with the same cabinet depth (24\").1. Remove and discard the top panel from thelower unit.2. Carefully lift the uncrated top unit onto thebottom unit. Use of a mechanical lift isrecommended for this step.3. Align the two ice maker cabinets.4. Secure the top unit to the bottom one with thehardware and straps shipped with the uppermachine.5. Locate and uncoil all of the bin thermostatcapillary tube.6. Route the bin thermostat capillary tube from theupper unit, through the hole in the back of thereservoir, through the lower unit and into the binthermostat bracket. Discard upper unit bracket.August 1994 Page 5

CME250Installation For The Plumber1. Connect cold potable water to the 3/8\" male Drain tube material must be rigid and meet localflare at the back of the cabinet. A water filter is code.recommended. Flush the water line prior toconnecting to the ice machine. Traps in the bin drain line without vents ahead of them will cause poor draining.If water cooled, connect a separate water inlet lineto the water cooled condenser inlet fitting. It should The bin drain must be vented if there is a longalso have a hand shut off valve. horizontal run (5’ or more). The reservoir drain must be vented and not connected to the bin drain.A loop of copper tubing may be used between the All drains are gravity, and must have a minimumice machine and the water supply. This will allow fall of 1/4\" per foot of horizontal run. The waterthe ice machine to be pulled out from its installed cooled condenser drain is not vented, and islocation without disconnecting the water line. No routed separately.back-flow preventer should be needed in the inletpotable water line because provision for that is Maintain the air gap required by local codeincorporated in this N.S.F. listed product (the tube between the end of the drain tubes and thefrom the inlet water valve has an air break in it, is building drain receptacle.above the reservoir wall and cannot siphon). Note: Drain tubing should be insulated to prevent2. Connect a drain tube to each drain. The drain condensation from forming on the tubing.tubes from these connections must be runseparately. There are two connections, one is the CONFORM TO ALL LOCAL CODESbin drain and the other is the reservoir drain. Thereservoir drain is a 3/4\" F.P.T. brass fitting. 3/8 Male Flare 3/8\" FPT Inlet Water Inlet 1/2\" FPT Water Shut Outlet Off Valve Water Cooled Reservoir Drain Condenser Plumbing 3/4\" FPT, Must Be Vented. ConnectionsBin Drain. May Be Routed From The Bottom On Some Model Ice Storage Bin Bins. Fitting May Be Plastic. (Typical) DO NOT OVERHEAT. Water Supply and Drain Connections October 1994 Page 6

CME250Installation For The ElectricianThis unit must be on a separate 115 volt AC 60cycle single phase power supply. The maximumfuse size for this circuit is listed on the nameplate,and per the nameplate use fuses, or HACR circuitbreakers.Electrical connections are made at the rear of theice maker, inside the junction box.Recommendation: If using wire nuts, cut \"tinned\"portion of connecting wires off and strip 1⁄2\" ofinsulation from the end of each wire.Follow All Local Codes - This Unit Must BeGrounded. Usually a licensed electrician will berequired to connect the electrical service. Hand Disconnect SwitchJunction Box August 1994 Page 7

CME250After Utility Connections1. Level the cabinet, use the leg levelers on theend of the legs to adjust the cabinet height. (Legsshould have been installed when the bin wasunpacked).2. Wash out the bin. If desired, the interior of thebin could be sanitized. Final Check List1. Is the ice maker cabinet in a room whereambient temperatures are within the minimum andmaximum temperatures specified?2. Has the water supply been connected?3. Is the water pressure adequate?4. Have the water connections been checked forwater leaks?5. Have the drain connections been made?6. Have the drain connections been checked forleaks?7. Is the cabinet level?8. Is the ice machine connected to a 115 voltelectrical power supply and is the ice machine theonly load on that circuit?9. Has all of the shipping material been removedfrom the inside of the cabinet?10. Has the bin thermostat bracket been attachedto the bottom of the ice machine, and the capillarytube routed thru the bracket?11. Has the bin and cabinet been wiped clean andsanitized?12. Has the Customer Evaluation & WarrantyRegistration form been properly filled out? Checkfor correct model and serial numbers from thenameplate, then mail the completed form toScotsman.13. Has the owner/user been given the name andtelephone number of the authorized ScotsmanService Agency serving that location? October 1994 Page 8

Component Location CME250The ice machine is designed for front service. WaterMany components are serviceable from the front Distributorswithout removing the side panels. Drain TroughBehind the front panel: • Water pump • Inlet water valve • Reservoir • Evaporators • Water distributor • Control box with cube size control adjustment • ON/OFF switch • Compressor switchInside the control box is control system for the icemachine.Timer Cube Size Control Master Switch Compressor Switch Bin Thermostat Control Box Overflow Standpipe Bin Thermostat Water Pump Bin ThermostatComponent Location Bracket Water Inlet Valve August 1994 Page 9

CME250COMPONENT DESCRIPTION: Control SystemCube Size Control Timer - Timer & Switch AssemblyThis reverse acting thermostat controls the length The function of the timer begins when activated byof the freezing cycle. It is sensing the temperature the cube size control. The outer surface, or largeof the suction line. When the suction line gets cold diameter lobe of the timer cam, determines theenough, the cube size control closes (on timer cycle for finish freezing of the ice cubes,temperature fall) and starts the timer. A change in while the inner surface, or small diameter lobe,either ambient air or incoming water temperature determines the time cycle for the harvest cycle.will affect the efficiency of the refrigeration system,and this will vary the length of time it takes the When the microswitch button is pushed in there isevaporator to reach the temperature at which the power connected to the coil of the relay, and thecube size control is preset to close. See CUBE unit is in the freeze cycle. When the microswitchSIZE ADJUSTMENT BEFORE attempting to adjust button is released, the power to the relay isthe control. stopped, and the unit goes into harvest. The microswitch is actuated by a cam assemblyRelay directly connected to the timer motor.The multi-function, three pole, double throw, One complete rotation of the cam will take eightplug-in relay is installed directly into a receptacle minutes. Harvest is preset at two and a quarteron the printed circuit board in the control box. The minutes, but is adjustable.relay functions in part to by-pass the binthermostat control to prevent the ice maker from High Pressure Safety Cut Out Switchshutting OFF, when the bin thermostat opensduring the freezing cycle. The bypass action This is a manual reset control that shuts down theserves to ensure full-sized ice cubes with each ice maker, should the discharge pressure everharvest cycle. reach 450 PSIG (air cooled) or 400 PSIG (water cooled). Located next to the control box.CONTROL BOX High Pressure Cut Out Switch Cube Size ControlRelay Timer Bin Thermostat October 1994 Page 10

CME250Initial Start UpAfter the final check list has been gone through, Cam Follower Timerthe ice machine may be started up.1. Open the water shut off valve.2. Switch on the electrical power. Cam2. Remove the front panel.4. Remove the control box cover.5. Locate the timer and Control Box Timer Shown In Harvest Positionrotate the cam clockwiseuntil the timer is in the HarvestHarvest Position. Cube Size Freeze6. Switch the compressor Control Knobswitch to OFF.3. Locate the ON/OFFswitch, switch it to ON.4. The inlet water valve will Cubes Tooopen, and water will flow Thickinto the reservoir. Thewater pump will begin topump water over theevaporators.5. Allow the reservoir to fill. Bin Thermostat6. Switch the compressorswitch to ON.7. On air cooled models the fan motor will begin toturn, and warm air will be discharged from the leftside of the ice machine. On water cooled modelswarm water will begin to flow from the condenserdrain.Note: To optimize the balance between iceproduction and water use, the water cooleddischarge pressure must be 245 P.S.I.G. Checkdischarge pressure and adjust water regulatingvalve to obtain 245 P.S.I.G. discharge pressure.8. The water temperature in the reservoir will soon Correct Size & Shapebe 320F., and ice should begin to form on theevaporators. Note: In some cases some slush will Batch Weight Should Be About 2.75 toform in the reservoir. This is temporary and normal. 3 Pounds Per Cycle9. Allow the ice machine to operate for about 20minutes. The ice should be fully formed and shouldbe harvested within a few minutes.10. After harvest, check the ice cube size. Ifneeded, adjust the cube size by rotating theadjustment knob of the cube size control. Rotate it Cubes Too1/8 turn clockwise to make the cubes thicker, and Thinrotate it 1/8 turn counterclockwise to make thecubes thinner. The machine is designed to only harvestcubes that are the correct thickness. August 1994 Page 11

CME250Initial Start Up11. Check harvest time. The machine will have Electrical Sequence:to harvest all of the cubes before it goes backinto the freeze cycle. This describes the sequence through a complete cycle.Cam Follower Timer Freeze Cycle: During the first part of the freeze cycle, the iceCam machine compressor, fan motor if air cooled, and water pump are operating. The relay in the middle Timer Shown In Harvest Position of the circuit board is energized. Timed Freeze: Harvest Cube size control closes, connecting power to the: timer motor, and after a few (4.5-5.5) minutes this Freeze timer opens the circuit to the relay on the circuit board. This starts the harvest cycle.Increase the Harvest Time if there is less than 15 Harvest:seconds of harvest time after the last cube has In the harvest cycle, the water pump andfallen into the bin. compressor stay operating, and these two valvesDecrease the Harvest Time if there is much more are energized:than 15 seconds of harvest time after the last cubehas fallen into the bin. Note: Harvest time is • Hot gas valvedependent upon the water and air temperatures at • Inlet water valvethe ice machine. Colder air and water will result infaster ice making, but longer harvest cycles. Do The unit stays in the harvest cycle until the timerNOT adjust harvest time too short, as this will case has turned the cam which has pushed the timera freeze up of the evaporators. micro switch button IN. If the bin thermostat isTo Adjust Harvest Time: OPEN, the ice machine will stop. If the bin1. Disconnect electrical power. thermostat is CLOSED, the relay will energize, and2. Locate time cam in control box. the unit will make another batch of cubes.3. Loose set screw holding the two halves of thecam together, and rotate the front half to increaseor decrease the harvest portion of the cam (lowpart).4. Re tighten the set screw.5. Reconnect power and check cube size of thenext cycle, as it may require adjustment after theharvest time has been set.12. Check operation of the bin control circuit byholding ice on the bin control tube in the bin. Thissimulates bin full and the ice machine shouldswitch itself off at the end of a harvest cycle.13. Replace all the panels. The ice machine is nowready for automatic operation. October 1994 Page 12

Maintenance and Cleaning CME250Cleaning Schedule: Air Filter (air cooled only): •Scrub the outside of the cabinet once a week 1. Remove the grill on the right side of the unit. with soap and water. 2. Remove the filter pad from in front of the condenser. •Wash off the bin door, frame and gaskets daily. •Sanitize the bin interior once a month. 3. Wash the surface of the filter off with cold water, •Clean the water system and air cooled or, if torn or so dirty it can’t be cleaned, replace with a new filter. condenser a minimum of twice per year. If in an area of high mineral concentration in the water 4. Return the filter to its installed position. supply, clean water system 4 times a year.This ice machine will perform at its best when kept 5. Replace the grill. Do not operate the unit withoutclean. There are two areas to keep clean: The the filter in place.water system including the water reservoir,distributor tube and evaporator surface; and the Note: If the unit has been operated without theair cooled condenser filter and the condenser itself. filter in place, the fins of the condenser will become fouled with dirt, and must be cleaned. AInlet Water Valve Screens vacuum cleaner with a soft brush attachment will extract most loose dust stuck to the surface of theIf a restriction of incoming water is suspected, the condenser fins. If there is any doubt about dirtscreen on the inlet side of the water valve should inside the fins of the condenser, the cabinet shouldbe inspected & cleaned. Some models also have a be removed and a qualified service agent shouldstrainer in the water line; the strainer screen clean the condenser.should also be inspected for restricting minerals. Water cooled units: Inlet Water Valve The water cooled condenser may, over time and under certain water conditions, become internally restricted by minerals. These will have to be dissolved by acid or the condenser replaced. Only a qualified service agent should attempt this type of service.Inlet ScreenAugust 1994 Page 13

CME250 Stainless Steel Components Inside BinCleaning: Ice Storage Bin The stainless steel parts in the bin also require periodic cleaning. Chemicals in the water supply,The interior liner of the bin is in contact with a food such as chlorine, cause brown stains to appear onproduct: ice. The storage bin must be cleaned the surface of the stainless steel parts.regularly to maintain a sanitary environment. 1. General Cleaning - staining is usually removedEvery 30 days, the liner should be sanitized with a by washing the parts with ordinary cleaningcommercial ice machine sanitizer, according to the powder such as Bon-Ami or Copper-Glo anddirections of the sanitizer, or with a solution of water. After cleaning, rinse with clear water.household bleach and water: 2. Water treatment. The chlorine enters the1. Mix the bleach and water using the ratio of one machine from the municipal water supply. It can beounce of bleach to two gallons of water. removed from the water supply by using a charcoal or activated carbon water filter to treat the2. Wipe all interior surfaces of the ice storage bin water to the ice machine. If staining is severe,with the bleach and water. filters of this type are recommended.3. Allow to air dry. Exterior Cabinet Cleaning:Note: Always replace bin baffle if removed when The exterior cabinet may be cleaned by scrubbingcleaning. with soap and water. Do not use cleaners containing petroleum products.To Remove Scale: A nylon type brush may be used to scrub stubborn1. Mix a cleaning solution of 4 ounces of Scotsman deposits.Ice Machine Cleaner to 4 pints of hot(950F.-1100F.) water.2. Using rubber gloves, dip a nylon scouring padinto the cleaning solution and scrub the scale offthe liner.3. After the scale has been removed, rinse allsurfaces inside the bin with clean, potable water.October 1994 Page 14

Cleaning: Ice Maker CME2501. Remove front panel. 15. Switch master and compressor switches ON. 16. Replace the front panel2. Remove control box cover, and turn the timer 17. Discard the next batch of cubes to make surecam clockwise until the unit is in a harvest cycle. At all of the acid & sanitizer is gone.the end of the harvest cycle switch the master and /////////////////////////////////CAUTION///////////////////////////////compressor switches to OFF. Replace the control DO NOT use ice cubes produced from thebox cover. cleaning or sanitizing solutions. Be sure none remain in the bin.3. Remove all ice from the bin. ///////////////////////////////////////////////////////////////////////////////// 18. Pour hot water into the storage bin to melt the4. Remove 4 thumbscrews and the evaporator cubes and also clean out the bin drain.cover. 19. Wash the bin liner with a solution of household bleach (1 ounce of bleach to 2 gallons of water)5. Remove water pump discharge hose from and warm (95oF. - 115oF.) water. Allow to air dry.evaporator water inlet, direct hose into bin or 20. The unit will now continue automatic operation.bucket and switch the master switch ON until Water Distributor:reservoir is empty of water. Replace hose on inlet. Note: The water distributor may need to be cleaned separately.6. Replace evaporator cover. 1. Remove evaporator cover. 2. Remove water distributor assembly by pushingScotsman Ice Machine the assembly to the right until the left end clearsCleaner contains acids. the retaining tab.These compounds maycause burns. Removal of Water DistributorIf swallowed, DO NOTinduce vomiting. Give Waterlarge amounts of water or Distributormilk. Call Physicianimmediately. In case of Retainingexternal contact, flush Tabwith water.KEEP OUT OF THE 3. Lift up the left end of the water distributorREACH OF CHILDREN. assembly and pull the assembly to the left. 4. Un-snap the water distributors from the \"T\", and7. Mix 8 ounces of Scotsman Ice Machine Cleaner inspect for mineral deposits. Clean as required.with 1 gallon of warm (950F. - 1150F.) water and 5. Reverse above steps to reassemble. Be certainpour into the reservoir until full. that water distributors are in place and secure. Scale that may form on the plastic liner can be8. Switch the master switch ON, and operate the removed by scrubbing the surface with a mixtureunit for 20 minutes, then switch the unit OFF. of Scotsman Ice Machine Cleaner and hot water. Remove any scale prior to cleaning.9 Repeat steps 4 and 5.10. Wash the plastic and stainless liners of thefreezer section with a solution of household bleach(1 ounce of bleach to 2 gallons of water) and warm(95oF. - 115oF.) water. Allow to air dry.11. Pour 1⁄2 gallon of the solution mixed in step 10into the reservoir. Replace the evaporator cover.12. Switch the master switch back ON, operate theunit for 5 minutes. Switch unit OFF.13. Repeat steps 4, 5 and 6.14. Pour about 1/2 gallon of clean potable waterinto the reservoir, and switch the master switchON. After 5 minutes switch the master switch OFFand repeat steps 4, 5 and 6.August 1994 Page 15

CME250 Water Schematic:Refrigeration Schematic: Water flows into the ice machine from its inlet connection at the back of the cabinet, through theFreeze Cycle: inlet water valve and into the reservoir. The water in the reservoir is pumped up and through theFrom the compressor, hot discharge gas is water distributor tube at the top of the evaporators.pumped to the condenser, either air or water From there, the water flows over both sides of thecooled. evaporators and back into the reservoir. Melted ice and water spills into the bin flow through a drain inAt the condenser, heat from the refrigerant flows the base of the bin to the exterior drain connectioninto the cooling medium, either air or water, and at the back of the cabinet.the refrigerant condenses into a liquid. From thecondenser the liquid refrigerant flows through theliquid line to the metering device - a thermostaticexpansion valve.At the expansion valve, the liquid refrigerantpasses from a high pressure zone to one ofrelatively low pressure, and in the low pressurezone it evaporates. The low pressure zone wherethe refrigerant evaporates is the evaporator. Whenthe refrigerant evaporates, it absorbs heat from themetal parts of the evaporator and the water flowingover it.From the evaporator, the refrigerant flows back tothe compressor through the suction line. Water Distribution Hot Gas Valve Suction Line System Liquid Line Evaporator Hot Gas Condenser Valve Fan Motor Water Filter Pump InletWaterValve Thermo Exp. ValveWater Reservoir Discharge Line Compressor Dryer Refrigeration Schematic October 1994 Page 16

Harvest Cycle: CME250During the harvest cycle, the refrigerant flows from During the Harvest Cycle, the inlet water valvethe compressor, through the discharge line to a opens, filling the reservoir and allowing thebranch in the line containing the Hot Gas Valve. reservoir to overflow the drain.This valve is Open during the harvest cycle,allowing the hot discharge gas to bypass thecondenser and enter the evaporator at its inlet.The hot discharge gases warm up the evaporatorenough to allow the surface of the ice frozen to theevaporator to melt. The remaining ice will then falloff into the bin. Water Distribution Hot Gas Valve Suction Line System (OPEN) Liquid LineEvaporator Condenser Fan Motor Water Hot Gas Inlet Pump Valve Water Filter Valve(OPEN) Thermo. Exp. ValveWater Reservoir Discharge Line Compressor Dryer Refrigeration Schematic August 1994 Page 17

CME250Technical CharacteristicsTypical Cycle Time • 21 minutes @ 90oF. air and 70oF. water • 16 minutes @ 70oF. air and 50oF. waterTypical Harvest Ice Weight • 2.5 - 3 pounds.Typical Low Side Pressure Just Before Harvest • Air cooled = 35 PSIG; Water cooled = 28 PSIGTypical Freeze Cycle Air Cooled Discharge Pressure • 220 PSIG @ 70oF. air and 50oF. water • 280 PSIG @ 90oF. air and 70oF. waterRefrigerant Charge: • Air cooled = 27 ounces HP62 • Water cooled = 17 ounces HP62Harvest Time • Pre-set at 2 and a quarter minutes. Adjustable to match field requirements.Typical Low Side Pressure, in harvest: • Water cooled = 86 PSIG ; Air cooled = 100 PSIG @ 90oF. air and 70oF. waterTypical Discharge pressure, in harvest: • Water cooled = 160 PSIG; Air cooled = 200 PSIG @ 90oF. air and 70oF. waterHi Pressure Cut Out Point: • 450 PSIG, air cooled; 400 PSIG, water cooledFan Pressure Switch • 240 PSIG C.I. • 190 PSIG C.O.Hi Temperature Cut Out Point: • 140oF. (at hot gas valve)Typical Compressor Amp Draw: • 10-13 during the freeze cycle and 11-14 during the harvest cycle.Compressor: • Copeland: RS43C1E-CAA-213Water Inlet Valve Flow Rate: • .33 g.p.m.Cube Size Thermostat: • Adjustable Cut In as needed to obtain correct cube size, C.I. range between 24oF. and 0oFBin Thermostat • Adjustable; C.I. range between 38.5oF. and 43.5oF, C.O. range between 33.5 oF. and 38.5 oFThermostatic Expansion Valve •Not adjustable October 1994 Page 18

CME250Service Diagnosis:SYMPTOM POSSIBLE CAUSE PROBABLE FIXNo ice is made, nothing operates Unit off, due to no power Restore powerNo ice is made Unit off, due to master switch in Switch master switch to ON OFF position Unit off, due to bin thermostat Check temperature at bin open thermostat bracket, if warmer than 40o F., thermostat should be closed. Adjust/replace thermostat. Unit off, due to hi pressure cut out Reset and check for dirty open condenser, hot location, or water interruption (if water cooled). Unit off, due to hi temperature cut Hot gas valve leaking thru, out open replace hot gas valve. Unit off, due to circuit board open Check for short circuit and replace circuit board. No water due to water turned off. Reconnect water supply No water due to water filter Replace water filter plugged. No water due to inlet water valve Clean out inlet screen screen plugged No water due to strainer screen Clean out inlet screen plugged No water due to Inlet water valve Replace valve coil open No water due to inlet water valve Replace valve will not open Water in reservoir, but no water Water pump does not work, over evaporators replace pump No cooling at evaporator due to Switch compressor on. compressor switched off No cooling at evaporator due to Replace inlet water valve too much heat load because inlet water valve leaks thru No cooling at evaporator due to Replace hot gas valve hot gas valve leaking thru No cooling at evaporator due to Check & replace fan motor or fan fan not turning control switch No cooling at evaporator due to Clean condenser dirty condenser August 1994 Page 19

CME250 POSSIBLE CAUSE PROBABLE FIXService Diagnosis No cooling due to low refrigerant Locate leak, recover remaining charge refrigerant, replace dryer, SYMPTOM evacuate and weigh in nameplate No ice is made charge. Makes ice, but very little Will not harvest due to hot gas Check for voltage to coil in valve not opening. harvest, if there is voltage check Cubes are wrong size/shape coil, if coil is ok, replace hot gas valve Ice fused together in bin Water drips on ice No cooling due to compressor not Check compressor for voltage, operating continuity, and operation. Replace if found to be faulty. Will not harvest due to not Adjust harvest time longer. enough harvest time. Will not harvest due to lack of Check water supply & distribution water. system. Clean water system with Scotsman Ice Machine Cleaner. High discharge pressure, due to Check for causes of high dirty condenser, faulty fan motor, discharge pressure and correct. fan pressure switch, not enough water thru water cooled condenser. Inlet water temperatures and Advise user, suggest additional room ambient very high room cooling. Compressor inefficient Check/replace compressor Cube size control not adjusted Adjust cube size control properly Water system is restricted with Clean water system with minerals Scotsman Ice Machine Cleaner Not enough water Check water supply pressure Check water supply for restrictions Ice in bin too long Advise user to pour water on ice to ease removal Too many minerals in water Suggest water treatment to user. Water distributors loose Set water distributors in place on top of evaporator. Some water is normal. Advise user. Cube size too small Adjust thicker. Water system is dirty Clean water system with ice machine cleaner. October 1994 Page 20

Removal and Replacement Cube Size Pig-Tail CME250Cube Size Control: SocketBefore replacing the cube size control, it should bepositively determined that it is at fault.If it does not open when warm, replace it.1. Disconnect electrical power.Electrical shock hazard.Electrical shock cancause personal injury.Disconnect power beforebeginning to servicecomponents.2. Remove the front panel. Suction Line3. Remove the control box cover.4. Locate the cube size control.5. Remove the two screws holding the control tothe control box, and lift the control out.6. Pull the two wires off the posts of the cube sizecontrol.7. Follow the capillary tube of the cube size control Replacement of Cube Sizeand remove it from the grommet in the back of thecontrol box.8. Locate bulb on suction line.9. The end of the cube size control is inserted in asocket attached to the suction line. Pull it out of thesocket.10. Replace the cube size control with the properpart number, following the above steps from 9-1. August 1994 Page 21

CME250 Inlet Water ValveRemoval and Replacement The valve water to enter the reservoir during harvest but not during freeze. The valve mayWater Pump plug-up from minerals in the water, and may beThe pump provides the force to move the water cleaned rather than replaced.from the reservoir to the freezing surface. Thepump does not need oil, but if it becomes noisy, 1. Shut off the water supply.overheats, or will not pump it should be replaced.Be certain to confirm electrical faults with a 2. Unscrew the fitting at the back of the valve, andvoltmeter or ohmmeter before replacing the pump. pull the water inlet tube out of the valve body.The pump should be operating whenever thecompressor is. 3. Remove the screws holding the valve to the1. Unplug or disconnect the electrical power. bracket. Electrical shock hazard. 4. Unplug the electrical connection from the valve. Electrical shock can cause personal injury. 5. Remove the valve from the ice machine. Disconnect power before beginning to service 6. Reverse the above steps to reassemble. components.2. Unplug the pump from its connection. Inlet Water Valve3. Loosen the two fasteners holding the bracket tothe wall.4. Pull discharge hose from pump discharge port. Replacement of Water Pump5. Remove pump from ice machine.6. Remove bracket from pump.7. Reverse above steps to replace. Inlet Water Valve Screen Must Be Kept Clean October 1994 Page 22

CME250REFRIGERATION SYSTEM: HP62 Refrigerant (R-404A)THIS ICE MACHINE USES HP62 REFRIGERANT Pressure-Temperature Chart for HP62AND POLYOLESTER COMPRESSOR OIL VAPOR VAPORDO NOT USE MINERAL OIL IN THIS TEMP. PRESSUREREFRIGERATION SYSTEM. (DEG F) (PSIG) TEMP. PRESSURE -20 . . . . . . 17 •HP62 is a \"Near Azeotrope\", and therefore -18 . . . . . . 18 (DEG F) (PSIG) -16 . . . . . . 20 liquid charging is required. -14 . . . . . . 21 70 . . . . . . . 146 -12 . . . . . . 23 ¤ Weigh into the discharge side as much of the -10 . . . . . . 24 72 . . . . . . . 150 charge (as liquid) as possible. -8 . . . . . . . 26 74 . . . . . . . 155 -6 . . . . . . . 28 ¤ Install a sight glass between the suction side -4 . . . . . . . 29 76 . . . . . . . 161 -2 . . . . . . . 31 and the gage manifold. Use the manifold 0 . . . . . . . 33 78 . . . . . . . 166 valve to \"flash off\" the balance of the 2 . . . . . . . 35 refrigerant charge before it enters the suction 4 . . . . . . . 37 80 . . . . . . . 171 side. 6 . . . . . . . 39 8 . . . . . . . 41 82 . . . . . . . 177 •When the system is serviced, a special liquid 10 . . . . . . . 43 12 . . . . . . . 46 84 . . . . . . . 182 line dryer is required (see parts list). 14 . . . . . . . 48 16 . . . . . . . 50 86 . . . . . . . 188 •Polyolester oil absorbs water very easily, and 18 . . . . . . . 53 20 . . . . . . . 55 88 . . . . . . . 194 therefore when the system is opened for 22 . . . . . . . 58 service, it must be re-sealed as soon as 24 . . . . . . . 60 90 . . . . . . . 200 possible (15 minutes maximum). 26 . . . . . . . 63 28 . . . . . . . 66 92 . . . . . . . 206 •Special leak detection equipment is required to 30 . . . . . . . 69 32 . . . . . . . 72 94 . . . . . . . 212 locate small refrigerant leaks. Usually a leak 34 . . . . . . . 75 detector capable of detecting a Halogenated 36 . . . . . . . 78 96 . . . . . . . 219 refrigerant or HFC-134a will work. Check with 38 . . . . . . . 81 the leak detector manufacturer if in doubt. 40 . . . . . . . 85 98 . . . . . . . 225 42 . . . . . . . 88 •As with any other refrigerant, do NOT mix with 44 . . . . . . . 91 100 . . . . . . 232 46 . . . . . . . 95 air for leak testing. 48 . . . . . . . 99 102 . . . . . . 239 50 . . . . . . . 102 52 . . . . . . . 106 104 . . . . . . 246 54 . . . . . . . 110 56 . . . . . . . 114 106 . . . . . . 253 58 . . . . . . . 118 60 . . . . . . . 123 108 . . . . . . 260 62 . . . . . . . 127 64 . . . . . . . 132 110 . . . . . . 268 66 . . . . . . . 136 68 . . . . . . . 141 112 . . . . . . 275 114 . . . . . . 283 116 . . . . . . 291 118 . . . . . . 299 120 . . . . . . 307 122 . . . . . . 316 124 . . . . . . 324 126 . . . . . . 333 128 . . . . . . 342 130 . . . . . . 351 132 . . . . . . 360 134 . . . . . . 370 136 . . . . . . 379 138 . . . . . . 389 140 . . . . . . 399 142 . . . . . . 409 144 . . . . . . 420 146 . . . . . . 430 148 . . . . . . 441 150 . . . . . . 452 152 . . . . . . 464 154 . . . . . . 475 156 . . . . . . 487 158 . . . . . . 499August 1994 Page 23

CME250 Access Valves: To use the access valves: Remove the cap from the stem, use a 3/16\" allenREFRIGERATION SERVICE wrench to check that the valve is CLOSED. Then remove the core cap.General: Close the valve and replace the caps when the •Scotsman recommends that any work on the job is finished. The valve must be closed and the caps must be on or the valve will leak. refrigeration system only be done when it is certain that the system needs repair. Use Torque Stem Cap conservation minded service procedures: to 8-12 ft. lb. •Refrain from checking refrigeration Allen Torque Stem Torque Core Wrench to 6-8 ft. lb. Cap to 7-12 ft. lb. pressures without reason. There are many ways to determine the proper operation of a Access Valves Scotsman ice machine without using refrigerant gauges. Visual inspection of the water system, Note: There are no Schrader observation of the ice formation, amp draw, cores in the valve. voltage, and other techniques will lead to proper diagnosis. Scotsman also recommends that, at If the refrigeration system must be serviced, the the time of initial start up, gauges not be used. quality of service must insure that there will not be a repeat failure, as repeat failures will •Refrigerant should not be added except as a cause refrigerant to be discharged into the air by the failure or when the failure is corrected: way to determine the proper operation of the product. If the system was low on refrigerant, •If there has been a compressor burn out, check there is a leak, and it must be found and repaired. for acid in the oil. If acid is indicated, extra steps must be taken to clean up the system. •This system has a critical charge, it must be •Never use refrigerant to clean up or flush out a recharged with the correct amount of refrigerant as listed on the nameplate of the ice machine, refrigeration system. When system clean-up is or performance will suffer. required, the use of suction line filter-dryers and liquid line filter-dryers are recommended (they •Anytime the refrigeration system has been must be compatable with polyolester oil and HFC refrigerant). opened, the dryer should be replaced. Note: Only a HFC type dryer should be used. •Evacuate the system with a good vacuum •When brazing the tubing connections to the hot pump to 200 microns or less. If the triple evacuation method is used, the vacuum should gas valve or TXV the component must be be broken each time with dry nitrogen, not protected by heat sink material. refrigerant. Evacuation must be from both sides of the system.Recover, Recover and Reclaim or Recover andRecycle refrigerant. If an ice machine is to be discarded and still contains refrigerant, Scotsman recommends thatThe method chosen is up to the service company. the refrigerant be recovered, reclaimed, orThere are various mechanical devices that may be recycled so that it is not discharged into the air.used to recycle refrigerant at the field level,however, Scotsman requires that any refrigerantplaced into a Scotsman ice machine meet ARIspec 700-88. Reclaim programs are availablethrough most refrigerant wholesalers.October 1994 Page 24