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COMPONENT DESCRIPTION

Cube Size Control

This reverse acting thermostat controls the length
of the freezing cycle. It is sensing the temperature
of the suction line. When the suction line gets cold
enough, the cube size control closes (on
temperature fall) and starts the timer. A change in
either ambient air or incoming water temperature
will affect the efficiency of the refrigeration system,
and this will vary the length of time it takes the
evaporator to reach the temperature at which the
cube size control is preset to close. See CUBE
SIZE ADJUSTMENT BEFORE attempting to adjust
the control. 

Relay
The multi-function, three pole, double throw,
plug-in relay is installed directly into a receptacle
on the printed circuit board in the control box. The
relay functions in part to by-pass the bin
thermostat control to prevent the icemaker from
shutting OFF, when the bin thermostat opens
during the freezing cycle. The bypass action
serves to ensure full-sized ice cubes with each
harvest cycle. 

Timer - Timer & Switch Assembly 

The function of the timer begins when activated by
the cube size control. The outer surface, or large
diameter lobe of the timer cam, determines the
timer cycle for finish freezing of the ice cubes,
while the inner surface, or small diameter lobe,
determines the time cycle for the harvest cycle. 

When the microswitch button is pushed in there is
power connected to the coil of the relay, and the
unit is in the freeze cycle. When the microswitch
button is released, the power to the relay is
stopped, and the unit goes into harvest. The
microswitch is actuated by a cam assembly
directly connected to the timer motor. 

One complete rotation of the cam will take eight
minutes. Harvest is preset at three and one half
minutes, but is adjustable.

High Pressure Safety Control

This is a manual reset control that shuts down the
icemaker, should the discharge pressure ever
reach 400 PSIG. Located below the control box.

Low Pressure Control (Pump Down)

This pressure control connects power to the
compressor contactor coil. Its Cut In is 35 PSIG
and its Cut Out is 20 PSIG. Located below the
control box.

CONTROL BOX

CUBE

SIZE

CONTROL

RELAY

TIMER &

SWITCH

CMS1202R

September 1993

Page 14

Summary of Contents for CMS1202R

Page 1: ...fications 2 For the Installer Location Assembly 3 Stacking 4 For the Electrician 7 For the Plumber 8 Final Check List 9 Initial Start Up 10 Freeze Cycle Operation 12 Harvest Cycle Operation 13 Component Description 15 Cleaning 17 Specifications 19 Adjustments 20 Service Diagnosis 21 Removal and Replacement 25 Parts Lists and Wiring Diagrams are located in the center of this manual printed on yello...

Page 2: ...th the highest regard for safety and performance They meet or exceed the standards of U L N S F and C S A 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 parts and or other components not specifically approved by Scotsman Scotsman reserves the right to make design changes and or improvement...

Page 3: ...ce the machine Do NOT push the bin into postion instead lift it there Pushing a bin may damage the legs and leg mounts Level the bin in both the front to rear and side to side directions by adjusting the leg levelers 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 Ice Maker Install the modular cu...

Page 4: ...e uncrated top unit onto the bottom one and align the two cabinets Use of a mechanical lift is recommended for this step At the back of the two icemakers bolt the upper icemaker cabinet to the lower icemaker cabinet using the mounting straps and bolts from the hardware package A stacking kit is required to interconnect the CMS ice level controls EVAPORATOR COVER STACKING TRIM STRIP PART OF KSCMS48...

Page 5: ... 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 the end without access valves 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 REFRIGERANT CONNECTI...

Page 6: ...e line The 3 8 inch liquid line goes to the icemaker fitting marked liquid line Final Connections 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 tigh...

Page 7: ...the icemaker The remote condenser is designed to be powered from the ice machine There is a separate electrical junction box at the back of the ice maker for the remote condenser Wire the remote condenser to the ice maker in accordance with local and national electric codes All outdoor wiring must be in rainproof conduit The condenser fan motor will run whenever the compressor is running Electrica...

Page 8: ...d with a polyphosphate feeder gives about the best overall performance DRAIN Connections 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 to conform with the local plumbing code Install a vertical open vent on drain line high point to insure good draining The ideal drain receptacle is a trapped and vented floor drain Recomm...

Page 9: ...s the water supply line shut off valve installed and electrical wiring properly connected 9 Check all refrigerant lines and conduit lines to guard against vibration or rubbing and possible failure 10 Have the bin and cabinet been wiped clean 11 Has the Manufacturers Registration form been properly filled out Check for correct model and serial numbers from Serial nameplate then mail to the SCOTSMAN...

Page 10: ...e timer and the switch assembly Rotate the shaft of the timer and switch assembly clockwise until the actuator arm on the microswitch drops off outer cam into cam slot See Front View of Timer 6 Move the ICE OFF WASH to the ICE position 7 Check the water fill cycle For several minutes the inlet water valve will be open and water will flow into the reservoir Near the end of the fill cycle water shou...

Page 11: ... and water will result in faster ice making but require longer harvest cycles Do NOT adjust harvest time too short or the unit will not harvest all the ice The harvest time is set by loosening the set screw on the cam rotating the shaft so that the opening between the cams increase or decrease retightening the set screw when the cams are in the correct position More of an opening between the cams ...

Page 12: ...ill 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 ...

Page 13: ... 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 ...

Page 14: ...Timer Timer Switch Assembly The function of the timer begins when activated by the cube size control The outer surface or large diameter lobe of the timer cam determines the timer cycle for finish freezing of the ice cubes while the inner surface or small diameter lobe determines the time cycle for the harvest cycle When the microswitch button is pushed in there is power connected to the coil of t...

Page 15: ...t FULL it will not allow the machine to fill the bin any closer to the ice machine than about 8 and it 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 There are three parts to the control the transducer the circuit board and the ice level control switch FULL SOUND WAV...

Page 16: ...ates Gravity flow returns the unfrozen excess portion of water to the sump reservoir for recirculation Hot Gas Solenoid Valve The hot gas solenoid valve functions only during the harvest cycle to divert the hot discharge gas from the compressor by passing the condenser for direct flow in the evaporator plates to release ice cubes from the ice cube molds The hot gas solenoid valve is installed in a...

Page 17: ...ition 11 Remove the cap and drain the cleaning solution from the sump Replace the drain cap 12 Rotate the shaft of the timer and switch assembly CLOCKWISE to the harvest position low part of the cam against microswitch Move the ICE OFF WASH switch to the ICE position to start the Harvest cycle If after completing this procedure one or more evaporator plates does not have a full flow of water for e...

Page 18: ...ove scale 1 Mix a cleaning solution of 4 ounces of Scotsman Ice Machine Cleaner to 4 pints of hot 950 F to 1100 F water 2 Remove all ice from the bin 3 Using rubber gloves dip a nylon scouring pad into the cleaning solution and scub the scale off of the liner 4 After the scale has been removed rinse all of the surfaces inside the bin with clean potable water To sanitize the bin and ice machine Fol...

Page 19: ...t local conditions Typical Suction Pressure in Harvest 65 70 PSIG 70o F air and 50o F water 80 85 PSIG 90o F air and 70o F water Typical Discharge Pressure in Harvest 75 80 PSIG 70o F air and 50o F water 100 PSIG 90o F air and 70o F water Typical Compressor Amp Draw Single phase Beginning freeze 11 12 End of Freeze 8 9 Harvest 9 10 Three phase Three phase amps vary between 6 and 10 High Pressure C...

Page 20: ...quire a corresponding adjustment of the cube size control Rotating the shaft of the timer cam clockwise will allow putting the machine into either the freezing cycle or harvest cycle as required in the cleaning instructions To Adjust The Timer Switch Assembly The length of the harvest cycle can be changed by loosening the set screw on the cam and then rotating the shaft so that the opening between...

Page 21: ...ve leaks through Replace inlet water valve See electrical adjustment See electrical adjustment Makes thick ice freezes up Water inlet valve restricted Clean or replace valve Low water pressure Check water filter or supply Sump covers out of position Re position sump covers Cubes too large Inlet water valve leaks through Replace inlet water valve See electrical adjustment See electrical adjustment ...

Page 22: ...r stuck Replace timer Relay does not energize unit stuck in harvest Replace relay Long freeze cycle Water inlet valve leaks through Replace inlet water valve Water temperature too high Advise user Cubes too small Cube size set wrong Adjust cube size Cubes size control stuck closed Replace cube size control Cubes too large Water inlet valve leaks through Replace inlet water valve and adjust cube si...

Page 23: ... in nameplate charge Hot gas valve leaks thru At the end of the freeze cycle there should be frost on the evaporator end of the hot gas tubes if not replace the hot gas valve Liquid and discharge lines are in contact with each other Separate and insulate them Unit shuts off before bin is full Bin Ice level control is set to Partial Move bin Ice level rocker switch to Full Compressor cycles on and ...

Page 24: ...ower go to D 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 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 E Transducer or ice...

Page 25: ...nt 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...

Page 26: ...hine 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 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 Bin Ice Level Control Circuit Board 1 Disconnect Electrical...

Page 27: ...his valve be certain that the valve is the cause of the problem 2 Remove the front panel 3 Dischargeand recover the refrigerant 4 Unplug the coil of the valve 5 With the refrigeration system open unsweat the valve from the tubing 6 Place the new valve in position 7 Wrap the new valve body with wet rags Do not get any moisture in the valve 8 Carefully braze the valve to the tubing Examine the joint...

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