Scotsman MCM1062W Operator’s Manual

MCM1062W
INTRODUCTION
This manual is intended as a reference for the installation of a Scotsman ice maker model MCM1062.
TABLE OF CONTENTS
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Environmental Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Machine & Bin Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
For the Plumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
For the Electrician . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Final Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Page
Initial Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Component Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Service Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Removal and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
September 1993
Page 1
MCM1062W
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. The refrigerant charge information is for recharging, should that be necessary.
All utility 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.
September 1993
Page 2
FOR THE INSTALLER: Environmental Limitations
MCM1062W
Installation Limitations
The ice making portion of this ice system is designed to be installed indoors, in a controlled environment.
Minimum Maximum
0
Air Temp 50 Water Temp 40 Water Pressure 20 PSI 80 PSI Voltage 197 253 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.
F. 1000F.
0
F. 1000F.
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.
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.
September 1993
Page 3
FLOOR DRAIN
MCM1062W
FOR THE INSTALLER: Machine & Bin Assembly
Overview:
This ice system is comprised of 2 major assemblies:
1. The ice storage bin.
2. The ice maker itself.
Storage Bin:
1. Measure the location of the ice machine floor drain relative to the installed location of the bin.
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 mounting holes.
4. Move bin back to an upright position.
5. Align the back set of casters so that the wheel’s axles are in a line with each other. This will permit the bin to be rolled back and forth. Check the casters so that they are tight against the bottom of the bin. Do not extend the casters past the horizontal groove in the caster shank.
6. Remove all material that is packed inside the bin.
7. Hang the scoop and scoop holder from the front edge of 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.
3. Level the bin, in both the front to rear and side to side directions. Tighten the caster set screws when the leveling is complete.
4. 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.
5. 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.
6. 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"
September 1993
Page 4
MEASURE THIS
DISTANCE
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.
A separate water inlet is required for the condenser water supply.
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.
The water cooled condenser requires a separate drain line, and is NOT to be vented.
MCM1062W
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.
September 1993
Page 5
FUSES or HACR
CIRCUIT BREAKERS
MCM1062W
FOR THE ELECTRICIAN: Electrical Connect ions
See the NAMEPLATE for current requiremen ts to determine wire size to be used for electrical hookup. The cuber requires a solid chassis to chassis eart h ground wire. See Wi ring Diag ram.
Be certain the cu ber is conne ct ed to its own electrical circuit and individually fu se d. Voltage variation should not exceed ten percent of the nameplat e rating, even under start ing conditio ns . Low voltages ca n cause erra tic opera tion and may be responsible for seriou s da mag e to the icemaker.
Electrical connections are mad e at the rear of th e icemaker, inside the junction box.
The cuber is pac kag ed wit h a flexib le cord and matching recep tacle (not attached), use th em to make electrical conne ctio n betwe en the icema ker and the building’s ele ct ric al po wer, if allowed by local cod es .
All external wiring should conform to the national, state and local electrical code requirements. Usually an electrical permit and services of a licensed elec tr ic ian wil l be required.
ELECTRICAL JUNCTION BOX
September 1993
Page 6
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?
MCM1062W
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?
September 1993
Page 7
MCM1062W
INITIAL START UP
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. OPEN the water supply line shut off valve.
7. 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.
TIMER CAM POSITIONS
ACTUATOR
CAM & SHAFT
FREEZE
PORTION
MICROSWITCH
HARVEST
PORTION
Check that the water distributors are seated at the top of the evaporators and that water flows over all cube cells.
Note: Some water spray from the evaporators is normal when the machine is new. The spray wll go away after a few cycles.
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 switch, to the ON position.
12. Check operation of the freezing cycle: Ice forms beginning at the top of the evaporators. Freezing time will range between 17 and 25 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 20 minutes.
13. Check the discharge pressure. To optimize the balance between water use and ice production, the freeze cycle discharge pressure should be 220 P.S.I. G. If needed, adjust the water regulating valve until the freeze cycle discharge pressure is 220 P.S.I.G.
14. 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 be fully formed at the edges; will harvest off of the evaporators beginning with individual cubes at the top of the evaporator, then vertical strips for the balance; and will appear similar to the illustration for “Correct Size Cube”.
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:
8. Move the ON/WASH/OFF rocker switch to the ON position.
9. Observe water fill cycle: The inlet water valve will be open and filling the reservoir. This should take a few minutes. Near the end of that time the water reservoir should be draining out the reservoir drain.
September 1993
Counter clockwise to produce SMALLER sized ice cubes:
Or clockwise to produce LARGER ice cubes: Observe size of ice cubes in the next cube harvest
and adjust again if needed, until correct the ice cube size is achieved.
Page 8
INITIAL START UP
MCM1062W
15. Check Harvest Time.There must be enough time in harvest to defrost all the cubes but not an excessive amount that will waste capacity. The length of the harvest cycle is determined by the timer cam positions.
If needed, adjust the harvest time so there are about 15 seconds of harvest time left after the last cube has fallen from the evaporators.
Because harvest time varies with the water and air temperatures at the ice machine, colder air and water will result in faster ice making but longer harvest cycles. Do NOT adjust harvest time too
short or the unit will not harvest all the cubes.
CUBES (ACTUAL SIZE)
TOO
THICK
The harvest time is set by: loosening the set screw on the timer cam, rotating the shaft to open or close the distance between the high parts of the cams, and retightening the set screw. More of an opening between the high parts of the cam = more harvest time.
Detailed instructions are on the next page. An adjustment of the cube size control may be
needed after the harvest time has been changed, so check the cube size again.
16. Check ICE BIN LEVEL CONTROL The amount of ice maintained in the bin is
adjustable. The normal setting is “full”. The level of ice in the bin may be set 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 the ice level sensor. It’s a socket in the base about 2" in diameter and located left of the evaporator plates.
CORRECT
SIZE
CUBE
TOO
THIN
1
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
1
⁄4"
1
manual over the ice level sensor socket.
4. The unit will turn off at the end of the harvest cycle.
1
⁄4"
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.
17. Replace all panels, covers and screws.
18. Fill out and mail in the Warranty Registration and Customer Evaluation form.
19. Inform the user of the name and telephone number of the local service company. Also tell the user the maintenance requirements of the ice machine.
September 1993
Page 9
HARVEST
PORTION
SET SCREW
MCM1062W
ADJUSTMENT OF THE TIMER & SWITCH ASSEMBLY
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 into the freeze or harvest cycle, as required in the cleaning instructions.
/////////////////////////////WARNING///////////////////////////////// Disconnect electrical power supply to icemaker whenever adjustment procedures are performed.
///////////////////////////////////////////////////////////////////////////// To adjust the timer & switch assembly:
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 initiates the harvest cycle. An audible click can be heard, but in a noisy area, look at the cam and switch to observe the event
ACTUATOR
CAM & SHAFT
FREEZE
PORTION
TIMER CAM POSITIONS
MICROSWITCH
B. To start the FREEZING CYCLE: Slowly rotate the shaft of the timer and switch assembly clockwise until the actuator arm on the microswitch initiates the freezing cycle.
C. To adjust the length of the harvest cycle:
1. Loosen the adjustment screw on the cam and rotate the shaft of the cam to move the cam. 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.
TIMER ADJUSTMENT
MICROSWITCH
SHAFT OF
CAM
September 1993
Page 10
COMPONENT DESCRIPTION
MCM1062W
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 it’s 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.
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, 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.
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 one quarter minutes.
September 1993
Page 11
MCM1062W
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 machine’s 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.
ICE LEVEL
SELECTOR
SWITCH
ON/OFF/WASH SWITCH
THE AMOUNT OF ICE MAINTAINED
IN THE BIN CAN
BE SELECTED BY
THE USER
SOUND WAVES
FULL
September 1993
Page 12
3
4
1
2
1
4
COMPONENT DESCRIPTION
WATER PUMP
MCM1062W
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. Above the reservoir, but below the evaporators are the cube chutes, designed to retain any water splash from ice making or harvest. Most ice will be falling into the bin below the center evaporator.
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 350 PSIG.
WATER
DISTRIBUTION
SYSTEM
WATER
REGULATING
VALVE
STRAINER
EVAPORATOR
RESERVOIR
HIGH PRESSURE
CUT OUT
ELECTRIC WATER VALVE
September 1993
Page 13
MCM1062W
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 Cube Size Control: Reverse acting temperature control, contacts close between +24 High Pressure Safety Switch: Contacts open at 350 P.S.I.G.
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.
3
⁄4 gallon per minute during the harvest cycle.
0
F. and 00F.
FREEZE CYCLE Average Discharge Pressure 220 P.S.I.G. Suction pressure at the end of the freeze cycle 24-20 P.S.I.G. Freeze Time 15-17 minutes
HARVEST CYCLE Average Suction Pressure 70-80 P.S.I.G.
Harvest time is assumed to be 2.25 minutes. This can be adjusted to suit local conditions.
This machine uses R-22.
September 1993
Page 14
MCM1062W
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. ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// CLEANING: ICEMAKER
///////////////////////////////WARNING///////////////////////////// Electrical power needs to be on when doing in
place cleaning. /////////////////////////////////////////////////////////////////////////////
1. Remove front panel.
2. Switch the Wash/Off/Ice switch to OFF.
3. Remove the front liner.
4. Remove and discard all ice from the storage bin.
5. Locate the reservoir drain cap, remove the cap and drain the reservoir. Replace the drain cap. If the reservoir doesn’t drain completely, disconnect 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 pump to discharge the rest of the water. Reattach the hose to the water distributors.
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.
0
with 1 gallon of warm (95 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).
F. - 1150F.) water and
9. Switch the machine to “wash” and continue to add fresh water to flush residual cleaner from the system. Switch the Wash/Off/Ice switch off.
10. Sanitize the ice maker and bin, see “Sanitize Water System”.
11. Replace the front liner.
12. Switch the Wash/Off/Ice switch back on.
13. Replace the front panel
14. Check the next batch of cubes to make sure all of the acid taste is gone.
/////////////////////////////////CAUTION////////////////////////////// DO NOT use ice produced from the cleaning
solution. Be sure none remains in the bin. ////////////////////////////////////////////////////////////////////////////////
15. Remove and discard all ice from the storage bin, pour hot water into the storage bin to melt the cubes and also clean out the bin drain.
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
September 1993
Page 15
MCM1062W
CLEANING
SANITIZE WATER SYSTEM
1. Remove and discard all ice from the bin.
2. Remove front panel.
3. Drain the reservoir
4. Prepare 2.5 gallons of McDonald’s 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.
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 2.5 gallons of McDonald’s 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.
11. Move the master switch to ON.
RESERVOIR
DRAIN
September 1993
Page 16
ON/OFF/WASH
SWITCH
SERVICE DIAGNOSIS
MCM1062W
SYMPTOM
No ice, machine does not run 1. No electrical power 1. Restore power
No ice, compressor does not run, rest of ice machine does.
No ice, no water over evaporators 1. Water pump does not pump 1. Check/replace water pump
No ice, everything runs 1. Too much heat load 1. Check for slow leak thru of water
Low ice production 1. Too much heat load. 1. Check condenser air inlet
POSSIBLE CAUSE
2. Circuit breaker tripped or fuse blown
3. High pressure control open. 3. Reset HPC, check fan motor for
4. ice level control holding machine off
5. High temp. cut out open 5. Hot gas valve leaks thru, replace
6. Timer switch open 6. Replace timer
7. Master switch open 7. Check or replace switch.
8. Circuit board open 8. Replace circuit board.
1. Open contactor coil 1. Replace contactor
2. Thermostatic Expansion valve clogged or does not open.
2. No water in reservoir 2. Check/replace water inlet valve.
2. Low on refrigerant 2. Check pressures, if low
3. Suction pressure too high 3. Defective compressor - replace
2. Compressor inefficient. 2. Replace compressor
3. Non condensable gasses in refrigeration system.
PROBABLE CORRECTION
2. Reset breaker or replace fuse, check for electrical fault.
proper operation, and condenser coil for dirt.
4. Check ice level control circuit. See page 19.
hot gas valve
2. Check/replace TXV.
inlet valve.
find/repair leak; weigh in charge.
temperature. Check water temperature.
3. Check head pressure, if very high, and no other reason is suspected, replace refrigerant charge.
September 1993
Page 17
MCM1062W
SERVICE DIAGNOSIS
SYMPTOM POSSIBLE CAUSE PROBABLE CORRECTION
Low ice production 4. High head pressure, a result of a
dirty condenser
5. Hot gas valve leaks thru 5. Replace hot gas valve
6. High discharge pressure 6. If possible, reduce condenser
No ice falling in bin, unit frozen up 1. Cube size control will not close 1. Check temp. of suction line, cube
2. Timer motor open 2. Replace timer
3. Plug in relay contacts open 3. Replace relay
4. Not enough time during the harvest cycle to drop all ice
5. Cube size wrong 5. Adjust cube size
6. Hot gas valve restricted. 6. Replace hot gas valve.
7. Not enough water to help harvest. 7. Check for restriction of water
8. Head pressure too low 8. Check water reg./pressure
Ice maker stuck in harvest cycle 1. Relay coil open 1. Replace relay
2. Timer stuck in harvest cycle 2. Check for power to timer motor, if
3. Timer microswitch N.O. contacts will not close.
Ice is mal-formed 1. Shortage of water 1. Check for restriction of water
2. Evaporator water passages restricted.
3. Cube size set wrong 3. Adjust cube size control
Water overflows from reservoir into bin.
1. Restricted sump drain 1. Repair drain
2. Inlet water valve lets in too much water
4. Clean water circuit of condenser
water inlet temperature.
size control will not close if temp. too high. If temp. low enough, replace cube size control
4. Adjust timer for more harvest time
supply.
control valve. Check for low refrigerant charge.
power replace timer, if no power to timer motor, replace relay.
3. Replace timer.
supply. Check for leak.
2. Clean ice maker.
2. Replace valve
September 1993
Page 18
Electrical Shock Hazard Can Cause Personal Injury.
Disconnect Power Before Servicing.
Bin Thermostat Posts at Line Voltage.
MCM1062W
SERVICE DIAGNOSIS: Ice Level Control Circuit
CONDITION DETERMINE CAUSE PROBABLE CORRECTION
Ice Machine does not run, it has power to it, the high pressure control is closed, the on/off switch is set to ON.
Machine runs, makes ice, switches on and off, but ice level cannot be controlled.
Machine runs, but will not shut off. Board relay stuck closed. Check
A. Listen for a ticking sound from transducer.
B. Open bin door and twist transducer 1/4 turn and pull out.
DO NOT UNPLUG with power connected
transducer, the inside must be clean and dry.
Check power to bin level
C.
. Examine the
control board.
Disconnect electrical power
D. 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.
Ice level switch may be defective. On boards with a light, check by moving switch & watching light.
relay.
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
to machine circuit. If machine
starts, disconnect electrical power, remove jumper wire and reconnect electrical power. Then go to E.
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
If COM and N.O. are closed when power is off, replace board. If open, go to B above.
go back
PARTIAL VIEW OF CIRCUIT BOARD
12-1912-01
PLUG - IN
RELAY
BIN THERMOSTAT
POSTS MENTIONED IN
“D” ABOVE
September 1993
Page 19
REMOVAL OF TRANSDUCER
MCM1062W
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.
TRANSDUCER LOCATION
5. Unplug transducer and remove from the machine.
6. Reverse steps 1-5 to reassemble.
TRANSDUCER
SOCKET IN ICE
MACHINE BASE
PLUG
CONNECTION
September 1993
Page 20
REMOVAL AND REPLACEMENT
MCM1062W
/////////////////////////////////WARNING///////////////////////////// Disconnect electrical power before beginning. /////////////////////////////////////////////////////////////////////////////// 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 to re-insulate the cube size control bulb.
Water Distributor Tubes And Manifold Tubes To remove the water distributor tube and manifold tube:
Inlet Water Solenoid Valve Assembly To remove the inlet water solenoid valve assembly:
1. Shut OFF water supply to machine.
ELECTRICAL CORD
SOLENOID
VALVE
OUTLET
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.
REMOVAL OF THE INLET WATER VALVE
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.
4. Pull electrical cord connection from solenoid coil terminals.
4. Remove inlet water fitting from the water solenoid valve. To replace the inlet water valve assembly, reverse the removal procedures.
September 1993
Page 21
MCM1062W
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.
4. Remove thumb screw retaining pump to cross brace.
ELECTRICAL
CONNECTION
Hot Gas 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 in the nameplate charge.
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..
DISCHARGE
HOSE
PUMP
REMOVAL OF THE WATER PUMP
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.
2. Discharge and recover the refrigerant from the system.
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. Sweat in the new valve. Do not overheat.
7. Re-attach the TXV bulb to the suction line in the same place as the original. Be certain to re-insulate.
8. Weigh in the nameplate charge.
9. Replace all panels removed for service.
10. Reconnect electrical power.
September 1993
Page 22
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