Scotsman ACM 45 User manual

Page 1
Page 1
SERVICE MANUAL
ACM 45
ACM 55
R 134 AVERSION
Electronic cubers
with storage
MS 1000.04 REV. 06/2000

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Page 2
Table of contents page
Specifications ACM 45
Specifications ACM 55
GENERAL INFORMATION AND INSTALLATION
Introduction
Unpacking and Inspection
Location and levelling
Electrical connections
Water supply and drain connections
Final check list
Installation practice
OPERATING INSTRUCTIONS
Start up
Operational checks
OPERATING PRINCIPLES (How it works)
Freezing cycle
Harvest cycle
Control sequence
Component description
ADJUSTMENT, REMOVAL AND REPLACEMENT PROCEDURES
Adjustment of the cube size
Replacement of evaporator temperature sensor
Replacement of ice level control sensor
Replacement of P.C. BOARD
Replacement of the water pump
Replacement of water inlet solenoid valve
Replacement of water drain valve
Replacement of condenser water inlet solenoid valve (Water cooled models)
Replacement of hot gas valve coil
Replacement of fan motor
Replacement of plastic curtain
Replacement of spray platform and chute
Replacement of drier
Replacement of hot gas valve body
Replacement of evaporator platen
Replacement of air cooled condenser
Replacement of hi pressure control (Water cooled models)
Replacement of water cooled condenser
Replacement of compressor
Wiring diagram
Service diagnosis
MAINTENANCE AND CLEANING INSTRUCTIONS
General
Icemaker
Cleaning instructions of water system
INDICE 2
3
5
25
26
26
26
26
26
27
27
27
27
27
28
28
28
28
28
29
29
29
30
31
7
7
7
8
8
8
9
10
11
16
19
19
21
33
33

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Important operating requirements:
Air temperature
Water temperature
Water pressure
Electr. voltage variations
from voltage rating
specified
on nameplate
MIN.
10°C
5°C
1 bar
-10%
°C
°F
SPECIFICATIONS
ELECTRONIC CUBER MODEL ACM 45
NOTE .Thedailyice-makingcapacityisdirectlyrelatedtothecondenserairinlettemperature,water
temperature and age of the machine.
TokeepyourSCOTSMANCUBERatpeakperformancelevels,periodicmaintenancechecksmust
be carried out as indicated on page 33 of this manual.
MAX.
40°C
40°C
5 bar
+10%
ice making capacity
24
23
22
21
20
19
18
17
16
15
Kg.
32 27 21 15 10
AIR COOLED MODELS
WATER TEMPERATURE
AMBIENT TEMPERATURE
ICE PRODUCED PER 24 HRS.
10
21
32
38
WATER COOLED MODELS
°C
o
°C
o
24
23
22
21
20
19
18
17
16
15
Kg.
32 27 21 15 10
10
21
32
38
°C
o
°C
o
WATER TEMPERATURE
AMBIENT TEMPERATURE
ICE PRODUCED PER 24 HRS.

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ACM 45 AS 6 Air
ACM 45 WS 6 Water Stainless steel 1/4 14 Kg.
Start . Electric power cons.
Amps Kwh per 24 Hr
Capacity Water req.
the cold store lt/24 HR
Model Cond. unit Finish Comp. HP
SPECIFICATIONS
Basic electr. Amps Watts Nr. of wires Amps fuse
230/50/1 2.2 11 340 6.5 3 x 1.5 mm210
100*
270*
ACM 45 - CUBER
machine specifications
Cubes per harvest: 18 medium
* A 15°C water temperature
Dimensions:
HEIGHT 725 mm.
WIDTH 457 mm.
DEPTH 480 mm.
WEIGHT 39 Kgs.

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Page 5
MIN.
10°C
5°C
1 bar
-10%
Important operating requirements:
Air temperature
Water temperature
Water pressure
Electr. voltage variations
from voltage rating
specified
on nameplate
°C
°F
SPECIFICATIONS
ELECTRONIC CUBER MODEL ACM 55
NOTE .Thedailyice-makingcapacityisdirectlyrelatedtothecondenserairinlettemperature,water
temperature and age of the machine.
TokeepyourSCOTSMANCUBERatpeakperformancelevels,periodicmaintenancechecksmust
be carried out as indicated on page 33 of this manual.
MAX.
40°C
40°C
5 bar
+10%
ice making capacity
32
30
28
26
24
22
20
18
Kg.
32 27 21 15 10
10
21
32
38
°C
o
°C
o
32
30
28
26
24
22
20
18
Kg.
32 27 21 15 10
10
21
32
38
°C
o
°C
o
AIR COOLED MODELS
WATER TEMPERATURE
AMBIENT TEMPERATURE
ICE PRODUCED PER 24 HRS.
WATER COOLED MODELS
WATER TEMPERATURE
AMBIENT TEMPERATURE
ICE PRODUCED PER 24 HRS.

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ACM 55 AS 6 Air
ACM 55 WS 6 Water Stainless steel 1/4 14 Kg.
Start . Electric power cons.
Amps Kwh per 24 Hr
Capacity Water req.
the cold store lt/24 HR
Model Cond. unit Finish Comp. HP
SPECIFICATIONS
Basic electr. Amps Watts Nr. of wires Amps fuse
230/50/1 2.2 11 390 7 3 x 1.5 mm210
0110 **
290*
ACM 55 - CUBER
machine specifications
Cubes per harvest: 24 medium
* A 15°C water temperature
Dimensions:
HEIGHT 738 mm.
WIDTH 457 mm.
DEPTH 522 mm.
WEIGHT 44 Kgs.

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9. See data plate on the rear side of the unit
and check that local main voltage corresponds
with the voltage specified on it.
CAUTION. Incorrect voltage supplied to
the icemaker will void your parts
replacement program.
10. Remove the manufacturer’s registration
card from the inside of the User Manual and fill-
in all parts including: Model and Serial Number
taken from the data plate.
Forward the completed self-addressed
registration card to Frimont factory.
11. On ACM 55, if necessary, fit the four legs
into their seats on the machine base and adjust
them to the desired level.
C. LOCATION AND LEVELLING
WARNING.This IceCuberis designedfor
indoorinstallationonly.Extendedperiods
of operation at temperatures exceeding
the following limitations will constitute
misuseunderthetermsoftheSCOTSMAN
Manufacturer’sLimitedWarrantyresulting
in LOSS of warranty coverage.
1. Position the unit in the selected permanent
location.
Criteria for selection of location include:
a)Minimumroomtemperature10°C(50°F)
and maximum room temperature 40°C (100°F).
b) Water inlet temperatures: minimum 5°C
(40°F) and maximum 40°C (100°F).
c) Well ventilated location for air cooled
models.
d) Service access: adequate space must
beleftforallserviceconnectionsthroughtherear
of the ice maker. A minimum clearance of 15 cm
(6")mustbeleftatthesidesoftheunitforrouting
cooling air drawn into and exhausted out of the
compartment to maintain proper condensing
operation of air cooled models.
2. Level the unit in both the left to right and
front to rear directions.
D. ELECTRICAL CONNECTIONS
See data plate for current requirements to
determine wire size to be used for electrical
connections.AllSCOTSMANicemakersrequire
a solid earth wire.
A. INTRODUCTION
This manual provides the specifications and the
step-by-stepproceduresfortheinstallation,start-
up and operation, maintenance and cleaning for
theSCOTSMANACM45andACM55icemakers.
The Electronic Cubers are quality designed,
engineered and manufactured.
Their ice making systems are thoroughly tested
providing the utmost in flexibility to fit the needs
of a particular user.
This product qualifies for the following listings:
These icemakers have been engineered to our
own rigid safety and performance standards.
NOTE .Toretainthesafetyandperformance
built into this icemaker, it is important that
installation and maintenance be conducted
in the manner outlined in this manual.
B. UNPACKING AND INSPECTION
1. CallyourauthorizedSCOTSMANDistributor
or Dealer for proper installation.
2. Visually inspect the exterior of the packing
and skid. Any severe damage noted should be
reportedtothedeliveringcarrierandaconcealed
damageclaimformfilledinsubjettoinspectionof
the contents with the carrier’s representative
present.
3. a)Cutandremovetheplasticstripsecuring
the carton box to the skid.
b) Remove the packing nails securing the
carton box to the skid.
c)Cutopenthetopofthecartonandremove
the polystyre protection sheet.
d) Pull out the polystyre posts from the
corners and then remove the carton.
4. Remove the rear panel of the unit and
inspectforanyconcealeddamage.Notifycarrier
ofyourclaimfortheconcealeddamageassteted
in step 2 above.
5. Remove all internal support packing and
masking tape.
6. Check that refrigerant lines do not rub
againstor touchother linesor surfaces,and that
the fan blade moves freely.
7. Check that the compressor fits snugly onto
all its mounting pads.
8. Use clean damp cloth to wipe the surfaces
inside the storage bin and the outside of the
cabinet.
GENERAL INFORMATION AND INSTALLATION

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All SCOTSMAN ice machines are supplied from
thefactorycompletelypre-wiredandrequireonly
electrical power connections to the wire cord
provided at rear of the unit.
Make sure that the ice machine is connected to
its own circuit and individually fused (see data
plate for fuse size).
Themaximumallowablevoltagevariationshould
not exceed -10% and + 10% of the data plate
rating. Low voltage can cause faulty functioning
and may be responsible for serious damage to
the overload switch and motor windings.
NOTE. All external wiring should conform to
national, state and local standards and
regulations.
Check voltage on the line and the ice maker’s
data plate before connecting the unit.
E. WATER SUPPLY AND DRAIN
CONNECTIONS
GENERAL
Whenchoosingthewatersupplyfortheicecuber
consideration should be given to:
a) Length of run
b) Water clarity and purity
c) Adequate water supply pressure
Sincewateristhemostimportantsingleingredient
in producting ice you cannot emphasize too
much the three items listed above.
Low water pressure, below 1 bar may cause
malfunction of the ice maker unit.
Water containing excessive minerals will tend to
produce cloudy coloured ice cubes, plus scale
build-up on parts of the water system.
WATER SUPPLY
Connect the 3/4" male fitting of the solenoid
waterinletvalve,usingafoodgradeflexibletube
or a 3/8" O.D. copper pipe, to the cold water
supply line with regular plumbing fitting and a
shut-off valve installed in an accessible position
between the water supply line and the unit.
If water contains a high level of impurities, it is
advisabletoconsidertheuseofthe WaterDrain
Valve-ortheinstallationofanappropriatewater
filter or conditioner.
OnWaterCooledversionthewaterinletsolenoid
valve has two separate outhets one for the
condenser and the second for the production of
ice.
WATER DRAIN
The recommended drain tube is a plastic or
flexible tube with 18 mm (3/4") I.D. which runs to
an open trapped and vented drain. When the
drain is a long run, allow 3 cm pitch per meter
(1/4" pitch per foot).
Aventattheunitdrainconnectionisalsorequired
for proper sump drainage.
WATER DRAIN - WATER COLLED MODELS
Connect the 3/4" male fitting of the condenser
waterdrain,utilizingasecondflexibletubingora
3/8"O.D.coppertubing,totheopentrappedand
vented drain.
NOTE. Thewatersupplyandthewaterdrain
must be installed to conform with the local
code. In some case a licensed plumber and/
or a plumbing permit is required.
F. FINAL CHECK LIST
1. Is the unit in a room where ambient
temperatures are within a minimum of 10°C
(50°F) even in winter months?
2. Is there at least a 15 cm (6") clearance
around the unit for proper air circulation?
3. Is the unit level? (IMPORTANT)
4. Have all the electrical and plumbing
connectionsbeenmade,andis the watersupply
shut-off valve open?
5. Has the voltage been tested and checked
against the data plate rating?
6. Has the water supply pressure been
checked to ensure a water pressure of at least
1 bar (14 psi).
7. Checkallrefrigerantlinesandconduitlines
to guard against vibrations and possible failure.
8. Havetheboltsholdingthecompressordown
been checked to ensure that the compressor is
snugly fitted onto the mounting pads?
9. Have the bin liner and cabinet been wiped
clean?
10. Has the owner/user been given the User
Manualandbeeninstructedontheimportanceof
periodic maintenance checks?

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11. Has the Manufacturer’s registration card
been filled in properly? Check for correct model
and serial number against the serial plate and
mail the registration card to the factory.
12. Has the owner been given the name and
thephonenumberoftheauthorizedSCOTSMAN
Service Agency serving him?
G. INSTALLATION PRACTICE
1. Hand shut-off valve
2. Water filter
3. Water supply line (flexible hose)
4. 3/4" male fitting
5. Vented drain
6. Open trapped vented drain
7. Drain fitting
8. Main switch
9. Power line
WARNING. This icemaker is not designed for outdoor installation and will not function in
ambient temperatures below 10°C (50°F) or above 40°C (100°F).
This icemaker will malfunction with water temperatures below 5°C (40°F) or above 40°C
(100°F).

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OPERATING INSTRUCTIONS
FIG. 1
Start up
Afterhavingcorrectlyinstalledtheicemakerand
completed the plumbing and electrical
connections, perform the following “Start-up”
procedure.
A. Remove the rear panel, locate the control
box and remove its cover.
B. Locatethegroovedhead(similartoafillister
screw head) of the electronic program selector
andwiththehelpofaregularscrewdriverturnthe
selector head in the OPERATION position.
C. Give power to the unit to start it up by
switching “ON” the power line main disconnect
switch.
The 1st GREEN LED will glow.
NOTE. Every time the unit returns under
power, after having been switched off, the
water inlet valve, the hot gas valve and the
water drain valve get energized for a period
of 5 minutes, thus to admit new water to the
machine sump reservoir to fill it up and,
eventually,towash-offanydirtthatcanhave
deposited in it during the unit off period
(Fig.1).
D. During the water filling operation, check to
seethattheincomingwaterdribbles,throughthe
evaporator platen dribbler holes, down into the
sump reservoir to fill it up and also that the
incoming surplus of water flows out through the
overflow pipe into the drain line.
During the water filling phase the components
energized are:
THE WATER INLET SOLENOID VALVE
THE HOT GAS SOLENOID VALVE
THE WATER DRAIN SOLENOID VALVE
2
1
3
4
7
L
N
8
6
5
VALVOLA SCARICO ACQUA
VALVOLA INGR. ACQUA
POMPA
COMPRESSORE
CONTENITORE
EVAPORATORE
TRASFOR-
MATORE
MICRO-
PROCESSORE
TIMER
ELETTR.
DIP
SWITCH
SCHEDA
ELETTRONICA
RELÈ
SENSORI
FUSIBILE
FUSIBILE
FUSIBILE
VALVOLA GAS CALDO
SELETTORE
RELÈ
RELÈ
VENTILATORE
TEMPERATURE
SENSORS
EVAPORATOR
BIN
SELECTOR
FUSE
ELECTRONIC
CARD
FUSE
FUSE
RELAY
RELAY
RELAY
ELECTR.
TIMER
DATA
PROCESSOR
TRANSF.
COMPRESSOR
FAN MOTOR
WATER PUMP
HOT GAS VALVE
WATER IN VALVE
WATER DRAIN VALVE

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NOTE . If in the 5 minutes length of the water
filling phase the machine sump reservoir
does not get filled with water up to the rim of
the overflow pipe, it is advisable to check:
1.Thewaterpressureofthewatersupplyline
thatmustbeatleast1bar(14psig)Minimum
(Max 5 bar-70 psig).
2.The filtering device installed in the water
line that may reduce the water pressure
below the Minimum value of 1 bar (14 psig).
3. Any clogging situation in the water circuit
like the inlet water strainer and/or the flow
control.
E. At completion of the water filling phase
(5minutes)theunitpassesautomaticallyintothe
freezing cycle with the start up of:
COMPRESSOR
WATER PUMP
FAN MOTOR (in air cooled version)
and the glowing of the 6th RED LED (Fig.2).
OPERATIONAL CHECKS
F. Install, if necessary, the refrigerant service
gauges on both the high side and low side
Schräder valves to check the compressor head
and suction pressures.
NOTE. On air cooled models the head
(condensing) pressure is kept between 11
and 7 bars (155 and 100 psig) with ice
machine at 21 ° C (70 ° F) ambient temperatu-
re. The above mentioned head pressure
values change accordingly to the ambient
temperature (rising with the rise of the tem-
perature) and to the ventilation of the unit.
Inthewatercooledmodels,theheadpressure
is kept between 8.5 and 10 bars (120-140
psig) by the operation of an automatic hi-
pressure control that energizes a second
outlet of the water inlet solenoid valve.
G. Check to see through the curtained ice
discharge opening that the spray system is
correctlyseatedandthatthewaterjetsuniformely
reach the interior of the inverted mold cups; also
make sure that the plastic curtain is hanging
freely and there is not excessive water spilling
through it.
H. Theicemakingprocesstakesplacethereby,
with the water sprayed into the molds that gets
gradually refrigerated by the heat exchange
occuring with the refrigerant flowing into the
evaporator serpentine.
FIG. 2
2
1
3
4
7
L
N
8
6
5
VALVOLA SCARICO ACQUA
VALVOLA INGR. ACQUA
POMPA
COMPRESSORE
CONTENITORE
EVAPORATORE
TRASFOR-
MATORE
MICRO-
PROCESSORE
TIMER
ELETTR.
DIP
SWITCH
SCHEDA
ELETTRONICA
RELÈ
SENSORI
FUSIBILE
FUSIBILE
FUSIBILE
VALVOLA GAS CALDO
SELETTORE
RELÈ
RELÈ
VENTILATORE
TEMPERATURE
SENSORS
EVAPORATOR
BIN
SELECTOR
FUSE
ELECTRONIC
CARD
FUSE
FUSE
RELAY
RELAY
RELAY
ELECTR.
TIMER
DATA
PROCESSOR
TRANSF.
COMPRESSOR
FAN MOTOR
WATER PUMP
HOT GAS VALVE
WATER IN VALVE
WATER DRAIN VALVE

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FIG. 3
FIG. 4
Duringthefreezingprocess,whentheevaporator
temperaturefallstoreach0°C(32°F)the evaporator
temperature sensor, located in contact with the
evaporator serpentine, supplies a low voltage
power signal to the electronic control device
(P.C.BOARD) which in first instance generates
the glowing of the 5th RED LED located in the
front of the printed circuit board (Fig.3).
2
1
3
4
7
L
N
8
6
5
–2°C
VALVOLA SCARICO ACQUA
VALVOLA INGR. ACQUA
POMPA
COMPRESSORE
CONTENITORE
EVAPORATORE
TRASFOR-
MATORE
MICRO-
PROCESSORE
TIMER
ELETTR.
DIP
SWITCH
SCHEDA
ELETTRONICA
RELÈ
SENSORI
FUSIBILE
FUSIBILE
FUSIBILE
VALVOLA GAS CALDO
SELETTORE
RELÈ
RELÈ
VENTILATORE
2
1
3
4
7
L
N
8
6
5
–13°C
VALVOLA SCARICO ACQUA
VALVOLA INGR. ACQUA
POMPA
COMPRESSORE
CONTENITORE
EVAPORATORE
TRASFOR-
MATORE
MICRO-
PROCESSORE
TIMER
ELETTR.
DIP
SWITCH
SCHEDA
ELETTRONICA
RELÈ
SENSORI
FUSIBILE
FUSIBILE
FUSIBILE
VALVOLA GAS CALDO
SELETTORE
RELÈ
RELÈ
VENTILATORE
TEMPERATURE
SENSORS
EVAPORATOR
BIN
SELECTOR
FUSE
ELECTRONIC
CARD
FUSE
FUSE
RELAY
RELAY
RELAY
ELECTR.
TIMER
DATA
PROCESSOR
TRANSF.
COMPRESSOR
FAN MOTOR
WATER PUMP
HOT GAS VALVE
WATER IN VALVE
WATER DRAIN VALVE
TEMPERATURE
SENSORS
EVAPORATOR
BIN
SELECTOR
FUSE
ELECTRONIC
CARD
FUSE
FUSE
RELAY
RELAY
RELAY
ELECTR.
TIMER
DATA
PROCESSOR
TRANSF.
COMPRESSOR
FAN MOTOR
WATER PUMP
HOT GAS VALVE
WATER IN VALVE
WATER DRAIN VALVE

Page 13
Page 13
Thethirdtime Ta -Timeadded -isinrelation
tooneofthedifferentcombinationsofthefive
keys 3, 4, 5, 6 AND 7 of the DIP SWITCH
located in the front of the P.C.BOARD. The
combinationisfactorysetinconsiderationof
theice makertype andof its coolingversion.
It is possible, however, to vary the timed
length of the freezing cycle, by changing the
DIP SWITCH keys settings.
In Table C of PRINCIPLE OF OPERATION
areshownthevarioustimeextensionsofthe
freezingcyclethirdphaseTa,inrelationwith
the different DIP SWITCH keys settings.
J. After about 20-22 minutes from the
beginning of the freezing cycle, in an hypothetic
ambient temperature of 21°C (70°F), the defrost
cycle takes place with the hot gas and the water
inlet valves being simoultaneously activated
(Fig.5).
The electrical components in operation in this
new situation are:
COMPRESSOR
WATER INLET SOLENOID VALVE
HOT GAS VALVE
WATER DRAIN SOLENOID VALVE
and the
WATER PUMP and FAN MOTOR for the first
15 - 20 seconds
I. The unit remains however in its normal
freezingcyclemodeuntilltheevaporatortempe-
rature detected by the sensor reaches the tem-
perature of -13°C (8.5°F).
When the evaporator temperature falls below
the above value, the evaporator temperature
sensorsuppliesalowvoltagepowersignaltothe
P.C.BOARD in order to activate the electronic
timer. This one takes over the control of the
freezingcycleuptothecompleteformationofthe
ice cubes (Fig.4) with the lighting up of the 4th
REDLEDlocatedjustabovethepreviouslighted
one.
NOTE. Thelengthoftheentirefreezingcycle
is the sum of the lengths of three phases,
two of which, (T1+T2) controlled by the
evaporatortemperaturesensor,whichhas
itsprobeplacedincontactwiththeevaporator
serpentine (Non adjustable), and one (Ta)
by the electronic timer (Adjustable)
incorporated in the P.C.BOARD.
Thelengthsofthefirsttwophases,relatedto
the evaporator temperature and controlled
by its sensor, are:
T1-Thetimeelapsed sincethebeginningof
freezing cycle up to when the evaporator
reaches the temperature of 0 ° C (32¯F).
T2 - The time required for the evaporator to
fall from 0 ° C (32 ° F) to -13 ° C (8.5 ° F).
FIG. 5
2
1
3
4
7
L
N
8
6
5
VALVOLA SCARICO ACQUA
VALVOLA INGR. ACQUA
POMPA
COMPRESSORE
CONTENITORE
EVAPORATORE
TRASFOR-
MATORE
MICRO-
PROCESSORE
TIMER
ELETTR.
DIP
SWITCH
SCHEDA
ELETTRONICA
RELÈ
SENSORI
FUSIBILE
FUSIBILE
FUSIBILE
VALVOLA GAS CALDO
SELETTORE
RELÈ
RELÈ
VENTILATORE
TEMPERATURE
SENSORS
EVAPORATOR
BIN
SELECTOR
FUSE
ELECTRONIC
CARD
FUSE
FUSE
RELAY
RELAY
RELAY
ELECTR.
TIMER
DATA
PROCESSOR
TRANSF.
COMPRESSOR
FAN MOTOR
WATER PUMP
HOT GAS VALVE
WATER IN VALVE
WATER DRAIN VALVE

Page 14
Page 14
NOTE. The length of the defrost cycle (not
adjustable)is automaticallydeterminatedby
themicroprocessorofP.C.BOARDinrelation
of the time T2 necessary for the unit to
reducetheevaporatortemperaturefrom0 ° C
(32 ° F) to -13 ° C (8.5 ° F) and of the ambient
temperature, as illustrated in Table B of
PRINCIPLE OF OPERATION.
As shown it is possible to have a different
lengthof the defrost cyclein connection with
the different length of the second phase of
the freezing cycle T2 related to the ambient
temperature situations; shorter when the
ambient temperature is high and longer in
colder ambients so to partially compensate
the length of the freezing cycle, which is
longer in high ambient temperatures and
shorter in low ones.
K. Check, during the defrost cycle, that the
incoming water flows correctly into the sump
reservoir in order to refill it and that its surplus
overflows through the overflow drain tube.
L. Checkthetextureoficecubesjustreleased.
They have to be in the right shape with a small
depression of about 5-6 mm in their crown.
Ifnot,waitforthecompletionofthesecond cycle
before performing any adjustment.
If the ice cubes require a correction of their
shape, it is possible to modify the length of the
timed freezing cycle by changing the DIP
SWITCH keys setting as illustrated on table C
shown in OPERATING PRINCIPLE.
If the ice cubes are shallow and cloudy, it is
possible that the ice maker runs short of water
during the freezing cycle second phase or, the
quality of the supplied water requires the use of
an appropriate water filter or conditioner.
M. To be sure of the correct operation of ice
level temperature sensor located in one side of
storage bin liner, place one shovel of ice cubes
in contact with its probe for approx. 30 sec.
1 minute.
Asthetemperatureofstoragebinsensorreaches
the value of +2°C (35°F), the ice level control
transmits a signal to the micro processor of the
P.C. BOARD in order to stop the ice maker
operation with the simultaneous glowing of the
3rd RED LIGHT, to monitor the BIN FULL
situation (Fig.6).
Withnomoreicecubesintouchwiththeicelevel
controlthetemperatureofitsprobeprogressively
risestoreach+4.5°C(40°F)andatthispoint the
ice machine restarts to initiate a new freezing
cycle with the simultaneous extinguishing of the
3rd RED LIGHT.
FIG. 6
2
1
3
4
7
L
N
8
6
5
VALVOLA SCARICO ACQUA
VALVOLA INGR. ACQUA
POMPA
COMPRESSORE
CONTENITORE
EVAPORATORE
TRASFOR-
MATORE
MICRO-
PROCESSORE
TIMER
ELETTR.
DIP
SWITCH
SCHEDA
ELETTRONICA
RELÈ
SENSORI
FUSIBILE
FUSIBILE
FUSIBILE
VALVOLA GAS CALDO
SELETTORE
RELÈ
RELÈ
VENTILATORE
TEMPERATURE
SENSORS
EVAPORATOR
BIN
SELECTOR
FUSE
ELECTRONIC
CARD
FUSE
FUSE
RELAY
RELAY
RELAY
ELECTR.
TIMER
DATA
PROCESSOR
TRANSF.
COMPRESSOR
FAN MOTOR
WATER PUMP
HOT GAS VALVE
WATER IN VALVE
WATER DRAIN VALVE

Page 15
Page 15
NOTE. The CUT-IN RANGE OF THE ICE
LEVELCONTROLSENSORcanbeadjusted
by means of the DIP SWITCH keys 8 and 9
as shown on table D of PRINCIPLE OF
OPERATION; its cut out setting remains
however at +2 ° C (35 ° F).
N. Removetherefrigerantservicegaugesand
re-fit the control box cover and the unit service
panels previously removed.
O. Instruct the owner/user on the general
operation of the ice machine and about the
cleaning and care it requires.

Page 16
Page 16
exchanges heat with the refrigerant flowing into
the capillary tube (warmer), before to be sucked
in the compressor and to be recirculated as hot
compressed refrigerant gas.
Thefreezingcycleiscontrolledbytheevaporator
temperaturesensor(whichhasitsprobeincontact
with the evaporator serpentine) that determines
thelengthofthefirstandsecondportionofit;the
starts up of the freezing cycle is signalled by the
glowing of the 6th RED LED.
ThefirstportionlengthortimeT1(Notadjustable)
is equal to the time required by the temperature
sensor to fall to 0°C (32°F). When reached, it is
signalled by the glowing of the 5th RED LED.
NOTE. If, after 15 minutes, the evaporator
temperaturehasnotyetreachedthevalueof
0 ° C(32 ° F)(duetoapartiallyortotalshortage
of refrigerant or to a too high condensing
temperature, etc.) the sensor, through the
P.C. BOARD, causes the unit to stop the
operation with the simoultaneous glowing of
the 2nd RED WARNING LED (Fig. 7).
Afterhavingeliminatedthesourceoftheunit
trip off, to restart the machine operation it is
necessaryfirsttorotatetheprogramselector
on RE-SET position, then put it again on to
OPERATIONpositionor,alternatively,switch
OFF and ON the hand disconnect Main
Switch.
Theicemachineresumesitsnormaloperation
by going through the 5 minutes water filling
phase.
PRINCIPLE OF OPERATION
How it works
In the SCOTSMAN cube ice makers the water
used to make the ice is kept constantly in
circulationbyanelectricwaterpumpwhichprimes
it to the spray system nozzles from where it is
diverted into the inverted mold cups of the
evaporator (Fig. A).
A small quantity of the sprayed water freezes
intoice;therestofitcascadesbygravityintothe
sump assembly below for recirculation.
FREEZING CYCLE
The hot gas refrigerant discharged out from the
compressor (Fig. B) reaches the condenser
where,beingcooleddown,condensesintoliquid.
Flowing into the liquid line it passes through the
drier filter, then it goes all the way through the
capillarytubewhere,duetotheheatexchanging
action, it looses some of its heat content so that
its pressure and temperature are lowered as
well. Next the refrigerant enters into the
evaporator serpentine (which has a larger I.D.
then the capillary) and starts to boil off; this
reaction is emphasized by the heat transferred
by the sprayed water.
The refrigerant then increases in volume and
changes entirely into vapor.
The vapor refrigerant then passes through the
suction accumulator (used to prevent that any
small amount of liquid refrigerant may reach the
compressor) and through the suction line. In
both the accumulator and the suction line it
FIG. 7
2
1
3
4
7
L
N
8
6
5
VALVOLA SCARICO ACQUA
VALVOLA INGR. ACQUA
POMPA
COMPRESSORE
CONTENITORE
EVAPORATORE
TRASFOR-
MATORE
MICRO-
PROCESSORE
TIMER
ELETTR.
DIP
SWITCH
SCHEDA
ELETTRONICA
RELÈ
SENSORI
FUSIBILE
FUSIBILE
FUSIBILE
VALVOLA GAS CALDO
SELETTORE
RELÈ
RELÈ
VENTILATORE
TEMPERATURE
SENSORS
EVAPORATOR
BIN
SELECTOR
FUSE
ELECTRONIC
CARD
FUSE
FUSE
RELAY
RELAY
RELAY
ELECTR.
TIMER
DATA
PROCESSOR
TRANSF.
COMPRESSOR
FAN MOTOR
WATER PUMP
HOT GAS VALVE
WATER IN VALVE
WATER DRAIN VALVE

Page 17
Page 17
FIG. A FIG. B
FIG. C FIG.D

Page 18
Page 18
The second portion length of freezing cycle or
time T2 (Not adjustable) is equal to the time
required by the evaporator temperature to go
from0°C(32°F)to-13°C(8.5°F).Thesensorwill
light-up the 4th RED LED.
NOTE. In casethe time T2 getslonger than
45minutes,theunitstopswiththeglowingof
the 2nd RED WARNING LED.
Thethird portion ortime Ta (Addedtime) ofthe
freezingcycleiscontrolledbytheelectronictimer
of P.C. BOARD. As the evaporator temperature
reaches the value of -13°C (8.5°F); the sensing
probe of the evaporator sensor (in contact with
theserpentine)changhesitselectricalresistance
causing a low voltage current to flow to the P.C.
BOARDwhich, thereby, activates an electronic
timer.
NOTE. The activation of the timer (Time
mode) of P.C. BOARD is signalled by the
glowing of 4th RED LED located in the front
of the P.C. BOARD.
ATTENTION. In case the length of the
second portion of freezing cycle or time
T2, lasts as long as between 35 and 45
minutes, the third portion or time Ta gets
skipped by the P.C. BOARD which puts
the unit directly in the defrost or harvest
cycle.
The length of the third portion of the freezing
cycle (adjustable) is pre-fixed and related to the
settingoftheDIP SWITCH keys3, 4, 5, 6 and7.
InTableCareindicatedthevariouslengthsofthe
third portion of freezing cycle (Time mode) in
accordance with the different combinations of
the DIP SWITCH KEYS. In Table A, herebelow
illustrated, are indicated the DIP SWITCH keys
combinations for the ACM 45 and ACM 55 at
different versions as they are set in the factory.
The electrical components in operation during
the freezing cycle are:
COMPRESSOR
FAN MOTOR (in air cooled version)
WATER PUMP
and during the timed phase of freezing cycle
(Time mode) they are joined by the
ELECTRONIC TIMER
On the air cooled versions the refrigerant head
pressure is gradually reduced from a value of
approx. 11 bars (155 psig), generally recorded
atthebeginningofthefreezingcyclewiththeunit
at21°C(70°F)ambienttemperature,toaminimun
valueofapprox.7bars(100psig) justattheend
of the freezing cycle few seconds before the
starting of the defrost cycle.
The declining of the pressure is subordinated to
thereductionoftheevaporatingpressure,caused
by the progressive growth of the ice thickness
into the inverted cup molds and to the flow of air
drown through the air cooled condenser by the
fan motor.
The above values are in relation as well to the
ambient temperature of the ice maker site and
they are subject to rise with the increase of this
temperature.
On the water cooled versions the refrigerant
head pressure ranges between 8.5 and 10.5
bars (120÷140 psig) being controlled by the
automatic hi pressure control that energizes a
water solenoid valve located on the inlet water
linetothecondenser,whichmodulatesthecooling
water rate to the condenser.
NOTE. In case the length of the first portion
of freezing cycle T1 or of the second portion
T2 gets longer respectively than 15 and 45
minutes for one of the following abnormal
reasons:
CLOGGED CONDENSER (Air cooled
version)
INSUFFICIENT FLOW OF COOLING
WATER (Water cooled version)
FAN MOTOR OUT OF OPERATION (Air
cooled version)
AMBIENTTEMPERATUREHIGHERTHAN
40 ° C (100 ° F)
the Micro Processor of the P.C. BOARD
causesthetotalandimmediateSHUT-OFFof
the machine in order to prevent the unit from
operating in abnormal and dangerous
conditions. When the ice maker stops on
account of this protective device, there is a
simultaneous glowing of the 2nd RED LED,
warning the user of the abnormal situation.
Once eliminated the source of the condenser
hi-temperature, to restart the machine first, it
is necessary to rotate for a while the program
selector on RE-SET position then, rotate it
againonOPERATIONpositionoralternatively
switch OFF and ON the unit power line Main
Switch. The ice machine resumes its normal
operationbygoingthroughtheusual5minutes
water filling phase.
DIP SWITCH 1 2345 678910
ACM 45 A & W ON OFF OFF OFF OFF ON ON OFF OFF ON
ACM 55 A & W ON OFF OFF ON ON OFF ON OFF OFF OFF
TAB. A DIP SWITCH KEYS FACTORY SETTING COMBINATIONS
PER MODEL AND VERSION

Page 19
Page 19
NOTE. The length of the defrost cycle (not
adjustable) changes in accordance with the
durationofthesecondportionofthefreezing
cycleT2andisrelatedaswelltotheambient
temperature(asshownon TableB).Infactin
highambienttemperaturesituationthedefrost
cycle is abbreviated so to recover some of
the time used for the longer freezing cycle.
At the end of the defrost cycle, both the hot gas
andthewaterinletvalvescloseandthemachine
starts again a new freezing cycle.
OPERATION - CONTROL SEQUENCE
At the start of freezing cycle the evaporator
temperature sensor controls the length of the
first T1 and second T2 portion of the freezing
cycle.Asitsensesthepredeterminedevaporating
temperature of -13°C (8.5°F) it supplies a low
voltage current to the P.C. BOARD in order to
activate the electronic timer which takes over
thecontroloftheremainingportionofthefreezing
cycle for a pre-fixed time Ta subordinated to the
DIP SWITCH keys setting (see Tab. C).
NOTE. The evaporator temperature
sensor,factorypre-set,isthe sameforallthe
models and is not adjustable in the field.
During the normal operation mode the length or
the total time of the freezing cycle ie equal to the
sum of the three partial times i.e.:
Tc = T1 + T2 + Ta
In case the length of the second portion of the
freezing cycle or time T2 gets long as to be
between 35 and 45 minutes, the total length of
the freezing cycle will be limited to:
Tc = T1 + T2
skipping the added time Ta, controlled by the
electronic timer.
IfinsteadthetimeT2getslongerthan45minutes
the unit stops immediately with the lighting up of
the warning 2nd RED LIGHT.
The same could happen in case the time T1
(1st portion of freezing cycle) gets longer than
15 minutes.
Once completed the freezing cycle 2nd or 3rd
phase(thislastoneis dependent ofthelengthof
the second phase of freezing cycle - T2) the
system goes automatically into the defrost cycle
Ts.
Thedefrostcyclealsohasapre-fixedlengththat
can vary in relation to the time T2, as shown in
Table B.
AtcompletionofthedefrostcycletheP.C.BOARD
put the unit into a new freezing cycle.
With the unit installed in a normal location (21°C
ambient temperature) at the start of the freezing
cycletherefrigerantsuctionorlo-pressurelowers
rapidly to 1.0÷0.9 bars (14÷12 psig) then it
declinesgradually-inrelationwiththegrowingof
the ice thickness - to reach, at the end of the
cycle, approx. 0÷0.1 bars (0÷1.5 psig) with the
cubes fully formed in the cup molds.
Thetotallengthofthefreezingcyclerangesfrom
20 to 22 minutes.
DEFROST OR HARVEST CYCLE
As the electronic timer has carried the system
throughoutthethirdphaseoffreezingcycleoras
soon as the second phase T2 is over (when its
lengthhasbeen as longas35 to 45minutes)the
defrost cycle starts.
NOTE. The length of the defrost cycle (not
adjustable) is related to the length of the
secondphaseoffreezingcycleT2asdetailed
in Table B.
The electrical components in operation during
this phase are:
COMPRESSOR
WATER INLET SOLENOID VALVE
HOT GAS SOLENOID VALVE
WATER DRAIN SOLENOID VALVE
WATER PUMP and FAN MOTOR for the first
15-20 seconds
The incoming water, passing through the water
inlet valve and its flow control (Fig. C) runs over
the evaporator platen and then flows by gravity
through the dribbler holes down into the sump/
reservoir.
Thewaterfillingthesump/reservoirforcespartof
the surplus water from the previous freezing
cycleto go out to thewaste throughthe overflow
pipe. This overflow limits the level of the sump
water which will be used to produce the next
batch of ice cubes.
Meanwhile,therefrigerantashotgas,discharged
from the compressor (Fig. D) flows through the
hot gas valve directly into the evaporator
serpentine by-passing the condenser.
The hot gas circulating into the serpentine of the
evaporator warms up the copper molds causing
the defrost of the ice cubes. The ice cubes,
released from the cups, drop by gravity onto a
slanted cube chute, then through a curtained
opening they fall into the storage bin.
On the versions equipped with the water drain
valve, the water pump remains in operation,
during the first 15-20 seconds of the defrost
cycle, to pump out, trough the opened water
drainvalve,theremainingwater(reachofminerals
and deposits) of the previous freezing cycle.

Page 20
Page 20
HARVEST (Time Ts)
Water Drain Phase (15-20 sec.)
Electrical components (Loads).... ON OFF
Compressor..................................... •
Water Pump .................................... •
Fan Motor (Air cooled only)............. •
Hot Gas Valve ................................. •
Water Inlet Valve............................. •
Water Drain Valve ........................... •
P.C.Board Relay 1 & 3 Coil............. •
P.C.Board Relay 2 Coil ................... •
Electronic Timer .............................. •
Electronic Controls & Sensors .... ON OFF
Evaporator Sensor .......................... •
Ice Level Sensor ............................. •
HARVEST (Time Ts)
Water Filling Phase
Electrical components (Loads).... ON OFF
Compressor..................................... •
Water Pump .................................... •
Fan Motor (Air cooled only)............. •
Hot Gas Valve ................................. •
Water Inlet Valve............................. •
Water Drain Valve ........................... •
P.C.Board Relay 1 & 3 Coil............. •
P.C.Board Relay 2 Coil ................... •
Electronic Timer .............................. •
Electronic Controls & Sensors .... ON OFF
Evaporator Sensor .......................... •
Ice Level Sensor ............................. •
OPERATION - ELECTRICAL SEQUENCE
The following charts illustrate which switches
and which components are ON or OFF during a
particular phase of the icemaking cycle.
Refer to the wiring diagram for a reference.
BEGINNING FREEZE (Time T1 and T2)
Electrical components (Loads).... ON OFF
Compressor..................................... •
Water Pump .................................... •
Fan Motor (Air cooled only)............. •
Hot Gas Valve ................................. •
Water Inlet Valve............................. •
Water Drain Valve ........................... •
P.C.Board Relay 1 Coil ................... •
P.C.Board Relay 2 & 3 Coil............. •
Electronic Timer .............................. •
Electronic Controls & Sensors .... ON OFF
Evaporator Sensor .......................... •
Ice Level Sensor ............................. •
TIMED FREEZE (Time Ta)
Electrical components (Loads).... ON OFF
Compressor..................................... •
Water Pump .................................... •
Fan Motor (Air cooled only)............. •
Hot Gas Valve ................................. •
Water Inlet Valve............................. •
Water Drain Valve ........................... •
P.C.Board Relay 1 Coil ................... •
P.C.Board Relay 2 & 3 Coil............. •
Electronic Timer .............................. •
Electronic Controls & Sensors .... ON OFF
Evaporator Sensor .......................... •
Ice Level Sensor ............................. •