Scotsman MCM1062 User manual

INTRODUCTION
This manual is intended as a reference for the
installation of a Scotsman ice maker model
MCM1062.
TABLE OF CONTENTS
Page
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Environmental Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
For the Installer
Machine & Bin Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
For the Plumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
For the Electrician . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Final Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Initial Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Component Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Service Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Removal and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
MCM1062W
September 1993
Page 1

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.
Aserial 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.
MCM1062W
September 1993
Page 2

FOR THE INSTALLER: Environmental Limitations
Installation Limitations
The ice making portion of this ice system is
designed to be installed indoors, in a controlled
environment. Minimum Maximum
Air Temp 500F. 1000F.
Water Temp 400F. 1000F.
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.
Scotsman reserves the right to make design
changes and/or improvements at any time.
Specifications and design are subject to change
without notice.
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.
NAMEPLATE, LOCATED ON
BACK PANEL.
A SERIAL NUMBER PLATE IS
LOCATED BEHIND THE
FRONT PANEL, NEAR THE
CONTROL BOX.
MCM1062W
September 1993
Page 3

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.
BIN BUMPER 5"
FLOOR DRAIN
MEASURE THIS
DISTANCE
MOUNTING
STRAPS AND
BOLTS
MCM1062W
September 1993
Page 4

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.
Aseparate 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.
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.
MCM1062W
September 1993
Page 5

FOR THE ELECTRICIAN: Electrical Connections
See the NAMEPLATE for current requirements to
determine wire size to be used for electrical
hookup. The cuber requires a solid chassis to
chassis earth ground wire. See Wiring Diagram.
Be certain the cuber is connected to its own
electrical circuit and individually fused. Voltage
variation should not exceed ten percent of the
nameplate rating, even under starting conditions.
Low voltages can cause erratic operation and may
be responsible for serious damage to the
icemaker.
Electrical connections are made at the rear of the
icemaker, inside the junction box.
The cuber is packaged with a flexible cord and
matching receptacle (not attached), use them to
make electrical connection between the icemaker
and the building’s electrical power, if allowed by
local codes.
All external wiring should conform to the
national, state and local electrical code
requirements. Usually an electrical permit and
services of a licensed electrician will be
required.
ELECTRICAL JUNCTION BOX
FUSES or HACR
CIRCUIT BREAKERS
MCM1062W
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?
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?
MCM1062W
September 1993
Page 7

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.
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.
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:
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.
TIMER CAM POSITIONS
MICROSWITCH
ACTUATOR
CAM &
SHAFT
HARVEST
PORTION
FREEZE
PORTION
MCM1062W
September 1993
Page 8

INITIAL START UP
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.
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.
2. When the machine is running, wait untIl near the
end of a “harvest” cycle.
3. Hold a flat object about the size of this service
manual over the ice level sensor socket.
4. The unit will turn off at the end of the harvest
cycle.
5. Slowly lower the flat object straight down.
6. The ice machine will start again at the point
where it will maintain the ice level.
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.
TOO
THICK
CORRECT
SIZE
CUBE
TOO
THIN
1 1⁄4"
1 1⁄4"
CUBES (ACTUAL SIZE)
MCM1062W
September 1993
Page 9

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
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 CAM POSITIONS
MICROSWITCH
ACTUATOR
CAM &
SHAFT
HARVEST
PORTION
FREEZE
PORTION
TIMER ADJUSTMENT
MICROSWITCH
SHAFT OF
CAM
SET SCREW
MCM1062W
September 1993
Page 10

COMPONENT DESCRIPTION
Compressor Contactor
The compressor contactor carries the compressor
line current. The contactor is wired so any control
in the pilot circuit, such as the bin control, and high
pressure controls, etc., will cause the contactor
holding coil to be de energized, when the control
contact OPENS, thereby breaking the circuit to the
compressor.
Cube Size Control
This reverse acting (closes on temperature fall)
thermostat determines how long the freezing cycle
will be. The cube size control closes 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.
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.
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.
MCM1062W
September 1993
Page 11

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
SOUND WAVES
1⁄4
3⁄4
1⁄2
FULL
THE AMOUNT OF
ICE MAINTAINED
IN THE BIN CAN
BE SELECTED BY
THE USER
MCM1062W
September 1993
Page 12

COMPONENT DESCRIPTION
Electric Water Inlet Valve
The water inlet solenoid valve fills the reservoir
assembly with water. Excess water overflows out
the overflow standpipe located at the back of the
reservoir. This action fills and rinses the reservoir
during each harvest cycle. The flow rate is .75
g.p.m.
Water Distribution System
The water distribution system evenly supplies
water to all cells of the evaporator plates. The
water pump pumps water from the reservoir up the
vertical tygon tube to the tee. From there water is
channeled through the water manifold to the water
distributors, above each evaporator plate, and
from six holes within each distributor, water flows
to the cells of each side of the evaporator plates.
Gravity flow returns the unfrozen excess portion of
water to the reservoir for recirculation.
Reservoir
The reservoir, located below the evaporators,
stores the inlet water charge, and collects the
water that flows over the evaporator plates. 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
Awater 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
RESERVOIR
HIGH PRESSURE
CUT OUT
ELECTRIC WATER VALVE
STRAINER
EVAPORATOR
WATER PUMP
WATER
REGULATING
VALVE
MCM1062W
September 1993
Page 13

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 1⁄4minutes.
The harvest time is adjustable as required.
Inlet Water Valve: Opens and admits 3⁄4gallon per minute during the harvest cycle.
Cube Size Control: Reverse acting temperature control, contacts close between +240F. and 00F.
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.
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.
MCM1062W
September 1993
Page 14

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
with 1 gallon of warm (950F. - 1150F.) water and
pour into the reservoir until full.
7. Switch the Wash/Off/Ice switch to “wash”. Let
the unit operate for 30 minutes, then switch the
unit off.
8. Drain the reservoir again (repeat step 5).
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.
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.
Strainer:
Awater 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
MCM1062W
September 1993
Page 15

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.
11. Move the master switch to ON.
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.
RESERVOIR
DRAIN
ON/OFF/WASH
SWITCH
MCM1062W
September 1993
Page 16

SERVICE DIAGNOSIS
SYMPTOM POSSIBLE CAUSE PROBABLE CORRECTION
No ice, machine does not run 1. No electrical power 1. Restore power
2. Circuit breaker tripped or fuse
blown 2. Reset breaker or replace fuse, check for electrical fault.
3. High pressure control open. 3. Reset HPC, check fan motor for
proper operation, and condenser
coil for dirt.
4. ice level control holding machine
off 4. Check ice level control circuit. See page 19.
5. High temp. cut out open 5. Hot gas valve leaks thru, replace
hot gas valve
6. Timer switch open 6. Replace timer
7. Master switch open 7. Check or replace switch.
8. Circuit board open 8. Replace circuit board.
No ice, compressor does not run,
rest of ice machine does. 1. Open contactor coil 1. Replace contactor
2. Thermostatic Expansion valve
clogged or does not open. 2. Check/replace TXV.
No ice, no water over evaporators 1. Water pump does not pump 1. Check/replace water pump
2. No water in reservoir 2. Check/replace water inlet valve.
No ice, everything runs 1. Too much heat load 1. Check for slow leak thru of water
inlet valve.
2. Low on refrigerant 2. Check pressures, if low
find/repair leak; weigh in charge.
3. Suction pressure too high 3. Defective compressor - replace
Low ice production 1. Too much heat load. 1. Check condenser air inlet
temperature. Check water
temperature.
2. Compressor inefficient. 2. Replace compressor
3. Non condensable gasses in
refrigeration system. 3. Check head pressure, if very high, and no other reason is
suspected, replace refrigerant
charge.
MCM1062W
September 1993
Page 17

SERVICE DIAGNOSIS
SYMPTOM POSSIBLE CAUSE PROBABLE CORRECTION
Low ice production 4. High head pressure, a result of a
dirty condenser 4. Clean water circuit of condenser
5. Hot gas valve leaks thru 5. Replace hot gas valve
6. High discharge pressure 6. If possible, reduce condenser
water inlet temperature.
No ice falling in bin, unit frozen up 1. Cube size control will not close 1. Check temp. of suction line, cube
size control will not close if temp.
too high. If temp. low enough,
replace cube size control
2. 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 4. Adjust timer for more harvest time
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
supply.
8. Head pressure too low 8. Check water reg./pressure
control valve. Check for low
refrigerant charge.
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
power replace timer, if no power to
timer motor, replace relay.
3. Timer microswitch N.O. contacts
will not close. 3. Replace timer.
Ice is mal-formed 1. Shortage of water 1. Check for restriction of water
supply. Check for leak.
2. Evaporator water passages
restricted. 2. Clean ice maker.
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 2. Replace valve
MCM1062W
September 1993
Page 18

PARTIAL VIEW OF CIRCUIT BOARD 12-1912-01
BIN THERMOSTAT
PLUG - IN
RELAY
POSTS MENTIONED IN
“D” ABOVE
SERVICE DIAGNOSIS: Ice Level Control Circuit
Electrical Shock Hazard Can
Cause Personal Injury.
Disconnect Power Before
Servicing.
Bin Thermostat Posts at Line
Voltage.
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.
A. Listen for a ticking sound from
transducer. 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.
B. Open bin door and twist
transducer 1/4 turn and pull out. DO
NOT UNPLUG with power
connected. Examine the
transducer, the inside must be
clean and dry.
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.
C. Check power to bin level
control board. Should be 12 volts from
transformer, if not replace
transformer. If there is power 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 level board
assembly defective. Replace transducer. Set bin level to FULL and aim at an object about
1-3 feet away. Machine should
restart. If this does not repair unit,
replace the board.
Machine runs, makes ice, switches
on and off, but ice level cannot be
controlled.
Ice level switch may be defective.
On boards with a light, check by
moving switch & watching light.
Replace ice level switch
Machine runs, but will not shut off. Board relay stuck closed. Check
relay. If COM and N.O. are closed when power is off, replace board. If open,
go to B above.
MCM1062W
September 1993
Page 19

TRANSDUCER LOCATION
TRANSDUCER
SOCKET IN ICE
MACHINE BASE
PLUG
CONNECTION
REMOVAL OF TRANSDUCER
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 counter-
clockwise and push up gently.
4. Pull transponder down until plug connection is
accessible.
5. Unplug transducer and remove from the
machine.
6. Reverse steps 1-5 to reassemble.
MCM1062W
September 1993
Page 20