Scotsman AC 105 User manual

SERVICE MANUAL
AC 105
R 134 A / R 404 AVERSIONS
Electronic cubers
with storage
MS 1000.08 REV. 09/99

Page 01
TABLE
OF CONTENTS
Table of contents page
Specifications AC 105
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
Wiring diagram
Service diagnosis
MAINTENANCE AND CLEANING INSTRUCTIONS
General
Icemaker
Cleaning instructions of water system
1
2
4
4
4
5
5
5
6
7
8
12
15
16
17
21
22
23
26
26
27

Page 02
SPECIFICATIONS
ELECTRONIC CUBER MODEL AC 105
Important operating requirements:
MIN MAX
Air temperature 10°C (50°F) 40°C (100°¯F)
Water temperature 5°C (40°F) 40°C (100°F)
Water pressure 1 bar (14 psi) 5 bar (70 psi)
Electr. voltage
variations from
voltage rating
specified on
nameplate -10% +10%
ice making capacity
NOTE. With the unit in “built-in” conditions, the ice production is gradually reduced in respect to the
levels shown in the graf, up to a maximum of 10% at room temperatures higher than 32 ° C.
The daily ice-making capacity is directly related to the condenser air inlet temperature, water
temperature and age of the machine.
To keep your SCOTSMAN CUBER at peak performance levels, periodic maintenance checks
must be carried out as indicated on page 26 of this manual.
50
48
46
44
42
40
38
36
34
32
30
Kg.
32 °C
AIR COOLED MODELS
WATER TEMPERATURE
AMBIENT TEMPERATURE
ICE PRODUCED PER 24 HRS.
°C
10
21
32
38
WATER COOLED MODELS
27 21 15 10
50
48
46
44
42
40
38
36
34
32
30
Kg.
32 °C
WATER TEMPERATURE
AMBIENT TEMPERATURE
ICE PRODUCED PER 24 HRS.
32
38
27 21 15 10
°C
10
21

Basic electr. Amps. Start Amps Watts No of Wires Amp. Fuse
Page 03
SPECIFICATIONS (CONT'D)
Electr. power cons.
Kwh per 24 Hrs
230/50/1 3.5 18 550 10 3 x 1 m/m 10
2
Cubes per harvest: 32 medium
* At 15°C (60°F) water temperature
AC 105 - CUBER MACHINE SPECIFICATION
Model Cond. Finish Comp. HP Ice bin cap. Water requirem
Kgs. LTx24 HR
AC 105 AS Air S/Steel 180*
3/8 18
AC 105 WS Water S/Steel 530*
FRONT VIEW
HEIGHT (without legs) 813 mm.
HEIGHT (with legs) 950 mm.
WIDTH 535 mm.
DEPTH 534 mm.
WEIGHT 44 Kgs.

A. INTRODUCTION
This manual provides the specifications and the
step-by-stepproceduresfortheinstallation,start-
up and operation, maintenance and cleaning for
the SCOTSMAN AC 105 icemakers.
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.
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)Pulloutthepolystyrepostfromthecorners
and then remove the carton.
4. Remove the front and (if any) the rear
panels of the unit and inspect for any concealed
damage. Notify carrier of your claim for the
concealed damage as steted in step 2 above.
5. Remove all internal support packing and
masking tape. (Leg package is located in the
storage bin compartment).
6. Check that refrigerant lines do not rub
against or tuch other lines or 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
Page 04
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 the SCOTSMAN Europe
Frimont factory.
11. If necessary fit the four legs into their seats
on the machine base and adjust them to the
desired level.
C. LOCATION AND LEVELING
WARNING.ThisIceCuberis designedfor
indoorinstallationonly.Extendedperiods
of operation at temperature exceeding
the following limitations will constitute
misuseunderthetermsoftheSCOTSMAN
Manufacturer’sLimitedWarrantyresulting
in LOSS or 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. Clean the air cooled condenser at
frequent intervals.
d)Serviceaccess:adequatespacemustbe
leftforallserviceconnectionsthroughtherearof
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.AllSCOTSMANicemakers require
a solid earth wire.
All SCOTSMAN ice machines are supplied from
thefactorycompletelypre-wiredandrequireonly
electricalpowerconnectionstowirecordprovided
at the 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, usingtheflexible tubesupplied
tothecoldwatersupplylinewithregularplumbing
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
advisable to consider the installation of an
appropriate water filter or conditioner.
Page 5
OnWaterCooledversionthewaterinletsolenoid
valve has two separate outlets 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 COOLED MODELS
Connect the 3/4" male fitting of the condenser
water drain, utilizing a second flexible tubing to
the open trapped and 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 level? (IMPORTANT)
2. Have all the electrical and plumbing
connectionsbeenmade, andisthe watersupply
shut-off valve open?
3. Has the voltage been tested and checked
against the data plate rating?
4. Have the bin liner and cabinet been wiped
clean?
5. Havetheboltsholdingthecompressordown
been checked to ensure that the compressor is
snugly fitted onto the mounting pads?
6. Has the owner/user been given the User
Manualandbeeninstructedontheimportanceof
periodic maintenance checks?
7. 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.
8. Check all refrigerant lines and conduit
lines to guard against vibrations and possible
failure.
9. Is the unit in a room where ambient
temperatures are within a minimum of 10°C
(50¯F) even in winter months?
10. Is there at least a 15 cm (6") clearance
around the unit for proper air circulation?

Page 6
12. Hastheownerbeengiventhenameandthe
phone number of the authorized SCOTSMAN
Service Agency serving him?
11. Has the water supply pressure been
checkedto ensure awater pressure ofat least 1
bar (14 psi).
WARNING.Thisicemakerisnotdesignedforoutdoorinstallationandwillnotfunction
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).
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
G. INSTALLATION PRACTICE

START UP
Afterhavingcorrectlyinstalledtheicemakerand
completed the plumbing and electrical
connections, perform the following “Start-up”
procedure.
A. Give power to the unit to start it up by
switching “ON” the power line main disconnect
switch.
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).
B. During the water filling operation, check to
seethattheincomingwaterdribbles,throughthe
evaporator platen dribbler holes, down into the
OPERATING INSTRUCTIONS
Page 7
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
NOTE.Ifinthe5 minuteslenghtofthewater
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.
16
15
14
13
2
1
7
8
9
10
3
4
5
6
11
12
Rx Tx
WATER IN VALVE
HOT GAS VALVE
CONTACTOR COIL
FAN MOTOR
WATER PUMP
- EVAPORATOR
- AMBIENT
- CONDENSER
TEMPERATURE SENSORSBINCOMPRESSOR
TRANSF.
DATA
PROCESSOR
ELECTR.
TIMER
DIP
SWITCH
ELECTRONIC CARD
L
N
RELAYS
RELAY
TRIAC
WATER DRAIN VALVE
FIG. 1

C. At completion of the water filling phase
(5minutes)theunitpassesautomaticallyintothe
freezing cycle with the start up of:
COMPRESSOR
WATER PUMP
FANMOTOR(inaircooledversion)controlledby
thecondensingtemperaturesensorlocatedwithin
the condenser fins (Fig.2).
OPERATIONAL CHECKS
D. Install, if required, the refrigerant service
gauges on both the high side and low side
Scraeder valves to check the compressor head
and suction pressures.
NOTE.On aircooledmodels,thecondenser
temperature sensor, which is located within
the condenser fins, keep the head
(condensing) pressure between 8.5 and 9.5
bar (110 ÷ 130 psig).
Page 8
Incaseofcondensercloggingsuchtoprevent
the proper flow of the cooling air or, in case
the fan motor is out of operation or shortage
of water in the water cooled condenser, the
condenser temperature rises and when it
reaches70 ° C(160 ° F)-foraircooledversion
- or 62 ° C (145 ° F) - for water cooled version -
the condenser temperature sensor shuts-off
theicemakerwiththeconsequentlight-upof
the RED WARNING LIGHT (Fig.3).
Afterhavingdiagnosedthereasonoftherise
of temperature and removed its cause, it is
necessary to turn the head of the selector -
alwaysusinganappropriatescewdriver-first
on the RE-SET position then return it on
previous OPERATION position or unplug
(waitfewseconds)andpluginagaintheunit,
thustoputthemachineinconditiontoinitiate
a new freezing cycle.
Themachinerestartswiththeusual5minutes
waterfillingphaseinordertoprovideenough
water into the sump tank.
16
15
14
13
2
1
7
8
9
10
3
4
5
6
11
12
Rx Tx
WATER IN VALVE
HOT GAS VALVE
CONTACTOR COIL
FAN MOTOR
WATER PUMP
- EVAPORATOR
- AMBIENT
- CONDENSER
TEMPERATURE SENSORSBINCOMPRESSOR
TRANSF.
DATA
PROCESSOR
ELECTR.
TIMER
DIP
SWITCH
ELECTRONIC CARD
L
N
RELAYS
RELAY
TRIAC
WATER DRAIN VALVE
FIG. 2

Page 9
16
15
14
13
2
1
7
8
9
10
3
4
5
6
11
12
Rx Tx
WATER IN VALVE
HOT GAS VALVE
CONTACTOR COIL
FAN MOTOR
WATER PUMP
- EVAPORATOR
- AMBIENT
- CONDENSER
TEMPERATURE SENSORSBINCOMPRESSOR
TRANSF.
DATA
PROCESSOR
ELECTR.
TIMER
DIP
SWITCH
ELECTRONIC CARD
L
N
RELAYS
RELAY
TRIAC
WATER DRAIN VALVE
16
15
14
13
2
1
7
8
9
10
3
4
5
6
11
12
Rx Tx
WATER IN VALVE
HOT GAS VALVE
CONTACTOR COIL
FAN MOTOR
WATER PUMP
- EVAPORATOR
- AMBIENT
- CONDENSER
TEMPERATURE SENSORSBINCOMPRESSOR
TRANSF.
DATA
PROCESSOR
ELECTR.
TIMER
DIP
SWITCH
ELECTRONIC CARD
L
N
RELAYS
RELAY
TRIAC
WATER DRAIN VALVE
FIG. 3
FIG. 4
E. Check to see through the ice discharge
openingthatthespraysystemiscorrectlyseated
and that the water jets uniformely reach the
interioroftheinvertedmoldcups;alsomakesure
thattheplasticcurtain ishangingfreelyandthere
is not excessive water spilling through it.

F. Theicemakingprocesstakesplacethereby,
with the water sprayed into the molds that gets
graduallyrefrigeratedbythe heatexchangewith
the refrigerant flowing into the evaporator
serpentine. During the freezing process, when
the evaporator temperature falls below an
established value, the evaporator temperature
sensorsuppliesalowvoltagepowersignaltothe
electronic control device (P.C.BOARD) in order
to activate an electronic timer. This one takes
over the control of the freezing cycle up to the
complete formation of the ice cubes (Fig.4).
NOTE.Thelenghtoftheentirefreezingcycle
is governed by the evaporator temperature
sensorwhich has its probe placed in contact
with the evaporator serpentine (Non
adjustable)incombinationwiththeelectronic
timer (Adjustable) incorporated in the
P.C.BOARD.Thetimeradjustmentisfactory
set in consideration of the ice maker type,
cooling version and ice cube size (Small,
Medium, Large). It is possible, however, to
modifythetimedlenghtofthefreezingcycle,
by changing the DIP SWITCH keys setting.
In Table B of PRINCIPLE OF OPERATION
areshownthevarioustimeextensionsofthe
freezingcycle second phase, in relation with
the different DIP SWITCH keys setting.
G. Afterabout17÷20minutesfromthebegin-
ning of the freezing cycle, in an hypothetic
ambienttemperatureof21°C,thedefrostcycle
takes place with the hot gas, the water inlet
and the water drain valves simoultaneously
activated (Fig. 5).
Theelectricalcomponentsinoperationonmodels
are:
COMPRESSOR
WATER INLET VALVE
HOT GAS VALVE
WATER DRAIN VALVE
and the
WATER PUMP
on the first 15 seconds.
NOTE. The lenght of the defrost cycle (not
adjustable)isautomaticallydeterminatedby
the micro-processor of the P.C. BOARD in
relation of the time necessary for the unit to
reducetheevaporatortemperaturefrom0 ° C
(32 ° F) to -13 ° C (8.5 ° F) - TIME T2.
H. Check, during the defrost cycle, that the
incoming water flows correctly into the sump
reservoir in order to refill it and that the surplus
overflows through the overflow drain tube.
Page 10
16
15
14
13
2
1
7
8
9
10
3
4
5
6
11
12
Rx Tx
WATER IN VALVE
HOT GAS VALVE
CONTACTOR COIL
FAN MOTOR
WATER PUMP
- EVAPORATOR
- AMBIENT
- CONDENSER
TEMPERATURE SENSORSBINCOMPRESSOR
TRANSF.
DATA
PROCESSOR
ELECTR.
TIMER
DIP
SWITCH
ELECTRONIC CARD
L
N
RELAYS
RELAY
TRIAC
WATER DRAIN VALVE
FIG. 5

oftheFOURTHYELLOWLIGHTindicatingUNIT
IN OPERATION and the extinguishing of the
“BIN FULL” YELLOW LIGHT.
NOTE. The ICE LEVEL CONTROL
(INFRAREDSYSTEM)isindependentofthe
temperature however, the reliability of its
detection can be affected by external light
radiations or by any sort of dirt and scale
sediment which may deposit directly on the
light source and on the receiver.To prevent
any possible ice maker malfunction, due to
negative affection of the light detector, it is
advisable to locate the unit where it is not
reached by any direct light beam or light
radiation,alsoitisrecommendedtokeepthe
bin door constantly closed and to follow the
instructions for the periodical cleaning of the
light sensor elements as detailed in the
MAINTENANCE AND CLEANING
PROCEDURES.
K. Remove,iffitted,therefrigerantservice
gauges and re-fit the unit service panels
previously removed.
L. Instruct the owner/user on the general
operation of the ice machine and about the
cleaning and care it requires.
Page 11
I. Checkthetextureoficecubesjustreleased.
They have to be in the right shape with a small
depression of about 5-6 mm in their crown.
Ifnot,waitforthecompletionof thesecondcycle
before performing any adjustment.
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.
J. To be sure of the correct operation of ice
level control device, place one hand between its
sensing “eyes” to interrupt the light beam.
The RED LIGHT located in the front of the
P.C.BOARD goes immediately OFF, and after
60seconds,theunitstopswiththesimultaneous
glowing of the 2nd YELLOW LIGHT to monitor
the BIN FULL situation (Fig.6).
Take the hand out from the ice level control
sensors to allow the resumption of the light
beam;theREDLIGHT,locatedinthefrontofthe
P.C.BOARD, will glow immediately.
After approximately 6 seconds the ice maker
resumeitsoperationwith theimmediateglowing
16
15
14
13
2
1
7
8
9
10
3
4
5
6
11
12
Rx Tx
WATER IN VALVE
HOT GAS VALVE
CONTACTOR COIL
FAN MOTOR
WATER PUMP
- EVAPORATOR
- AMBIENT
- CONDENSER
TEMPERATURE SENSORSBINCOMPRESSOR
TRANSF.
DATA
PROCESSOR
ELECTR.
TIMER
DIP
SWITCH
ELECTRONIC CARD
L
N
RELAYS
RELAY
TRIAC
WATER DRAIN VALVE
FIG. 6

PRINCIPLE OF OPERATION
How it works
Page 12
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.Asmallquantityofthesprayedwater
freezesintoice;therestofitcascadesbygravity
into the sump assembly below for recirculation.
FREEZING CYCLE
The hot gas refrigerant discharged out from the
compressorreachesthecondenserwhere,being
cooleddown,condensesintoliquid.Flowinginto
the liquid line it passes through the drier filter,
thenitgoesallthewaythroughthecapillarytube
where, due to the heat exchanging action, it
loosessomeofitsheatcontentsothatitspressure
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
exchanges heat with the refrigerant flowing into
thecapillary tube (warmer), before tobe sucked
in the compressor and to be recirculated as hot
compressed refrigerant gas.
Thefreezingcycleiscontrolledbytheevaporator
temperature sensor (which has its probe in
contact with the evaporator serpentine) that
determines the length of its first portion of the
cycle.
When the temperature of the evaporator
serpentine drops to a pre-set value, the
evaporator sensor probe changes its electrical
resistance allowing a low voltage current (15
volts) to flow to the P.C. BOARD which in turn
activates an electronic timer.
The timer, which is built-in the P.C. BOARD,
takes over from the evaporator temperature
sensor, the control of the freezing cycle up to its
completion.
NOTE.Thechangeoftheelectricpotentialof
the evaporator sensor with the consequent
activationofthetimer(Timemode)issignalled
bythe glowing-upof theRED LEDlocated in
the front of the P.C. BOARD.
ATTENTION. In case, after 15 minutes
from the beginning of the freezing cycle,
thetemperature of theevaporator sensor
probeis higher then 0°C(32°F)(shortage
of refrigerant, inoperative hot gas valve,
etc.) the P.C. BOARD switch OFF
immediately the unit with the
simultaneous blinking of the WARNING
RED LED.
The length of this second portion of the freezing
cycleis pre-fixedand related tothe setting ofthe
first four DIP SWITCH keys.
The DIP SWITCH keys setting is made in
consideration of the type of condenser used.
In Table B are indicated the various lengths of
thesecondportionoffreezingcycle(Timemode)
inrelationtothedifferentcombinationsoftheDIP
SWITCH KEYS.
In Table A herebelow are illustrated the DIP
SWITCHkeyscombinationsforthethreedifferent
models and 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
CONTACTOR COIL
and during the second phase of freezing cycle
(Time mode) they are joined by the
ELECTRONIC TIMER
The refrigerant head pressure, in the course of
the freezing cycle, ranges between 8.5 and 9.5
bars (110÷130 psig) in the air cooled version,
TAB. A
DIP SWITCH
1234
ACM 105 A & W
ACL 105 A & W
56 7 8910
FREEZING CYCLE DEFROST CYCLE DIAGN. W.PUMP KWD
DIP SWITCH FACTORY SETTING COMBINATIONS (PER MODEL AND VERSION)
ON
OFF ON OFF OFF OFF ON ON ON ON ON ON ON/OFF ON/OFF OFF OFF ON ON OFF OFF

Page 13
FIG. A
FIG. C
FIG. B
FIG. C FIG. D
FIG. A

FIG. A
FIG. E
FIG. C
FIG. F
FIG. G FIG. H
Page 14

and between 9.5 and 10.5 bar (135÷150 psig) in
thewatercooledversion,beingcontrolledbythe
temperature sensor probe located within the
condenser fins (air cooled version) or, on the
condenser tube coil (water cooled version).
Ontheair cooledversion,the condensertempe-
rature sensor, when senses a rising of the
condenser temperature beyond the pre-fixed
limit, changes its electrical resistance and
transmits a low voltage power flow to the Micro
ProcessorofP.C.BOARDwhichinturnenergizes,
through a TRIAC, the FAN MOTOR.
When the opposite situation occures, i.e. the
condensertemperaturegets belowthe pre-fixed
limit, the temperature sensor changes again its
electricalresistancereducingthereforethecurrent
flow to the P.C. BOARD to cause the fan motor
temporary cut-off.
NOTE. In case the condenser temperature
probesensesthatthecondensertemperatu-
re has rised to 70 ° C (160 ° F) - on air cooled
versions - or 62 ° C (145 ° F) - on water cooled
versions - for one of the following reasons:
CLOGGED CONDENSER (Air cooled
version)
INSUFFICIENT FLOW OF COOLING
WATER (Water cooled version)
FAN MOTOR OUT OF OPERATION (Air
cooled version)
AMBIENTTEMPERATUREHIGHERTHEN
40 ° C (100 ° F)
itcausesthetotalandimmediateSHUT-OFF
of the machine in order to prevent the unit
from operating in abnormal and dangerous
conditions.
Whentheice maker stops on account of this
protective device, there is a simultaneous
glowingoftheRED LED,warningtheuserof
the Hi Temperature situation.
After having eliminated the source of the
condenser hi-temperature, to restart the
machine it is necessary first to rotate for a
while the program selector on RE-SET
positionthenagainonOPERATIONposition
or to unplug (wait few seconds) and plug in
again the unit. The ice machine resumes its
normal operation by going through the 5
minutes water filling phase.
At the start of the freezing cycle the refrigerant
suction or lo-pressure lowers rapidly to 1 bar -
14psigthenitdeclinesgradually-inrelationwith
thegrowing of the ice thickness- to reach, atthe
end of the cycle, approx. 0 bar - 0 psig with the
cubes fully formed in the cup molds.
Thetotallengthofthefreezingcyclerangesfrom
20 to 25 minutes.
Page 15
DEFROST OR HARVEST CYCLE (Fig.E and G)
As the electronic timer has carried the system
throughout the second phase of freezing cycle,
the defrost cycle starts.
ATTENTION. In case the unit is able to
reach 0°C (32°F) evaporating temperatu-
re within 15 minutes, but after 45 minutes
fromthebeginningofthefreezing cycleit
has not yet reached the evaporator tem-
perature of -15°C (5°F) the machine goes
straight into the defrost cycle omitting
the timed portion of the freezing cycle
relied to the setting of the first four DIP
SWITCHES.
NOTE. The length of the defrost cycle (not
adjustable) is related to the length of the
second phase of freezing cycle T2. (Time to
drop the evaporating temperature from 0 ° C
(32 ° F) to -13 ° C (8.5 ° F).
The electrical components in operation during
this phase are:
COMPRESSOR
WATER INLET VALVE
HOT GAS VALVE
WATER DRAIN VALVE
and the
WATER PUMP
on the first 15 seconds.
The incoming water, passing through the water
inlet valve and the flow control, runs over the
evaporator platen and then flows by gravity
through the dribbler holes down into the sump/
reservoir. (Fig. F and H )
Thewaterfillingthesump/reservoirforcespartof
the surplus water from the previous freezing
cycleto go out tothe waste through the 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, 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.
NOTE. The length of the defrost cycle,
factory set, changes in accordance with the
durationofthesecondportionofthefreezing
cycle(TimeT2)thatis relatedto theambient
temperature.
Attheend ofthedefrost cycle,the hotgasvalve,
the water inlet valve and the water drain valve
closeandthemachinestartsagainanewfreezing
cycle.

OPERATION - CONTROL SEQUENCE
At the start of freezing cycle the evaporator
temperaturesensorcontrolsthelengthofthefirst
part of the freezing cycle. As it reaches a
predetermined temperature it supplies a low
voltage current to the P.C. BOARD in order to
activatetheelectronictimerwhichtakesoverthe
control of the freezing cycle for a pre-fixed time
according to the DIP SWITCH keys setting
(see Tab. B).
NOTE. The evaporator temperature sensor,
factorypre-set,isthesameforallthemodels
and is not adjustable in the field.
Once completed the freezing cycle 2nd phase
the system goes automatically into the defrost
cycle which has also a pre-fixed length. At
completion of the defrost cycle the P.C. BOARD
command the unit to start again a new freezing
cycle.
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
Electrical components (Loads) ON OFF
Compressor ...........................................•
Fan Motor (Air cooled only) and TRIAC ........ •
Hot Gas Valve ........................................ •
Water Inlet Valve.................................... •
Water Drain Valve .................................. •
P.C.Board Relay 1 Coil .......................... •
P.C.Board Relay 2 & 3 Coil....................•
Water Pump ...........................................•
Contactor Coil ........................................•
P.C.B. Timer........................................... •
Elctronic Controls & Sensors ON OFF
Evaporator Sensor ................................. •
Condenser Sensor .................................•
Ice Level Control ....................................•
TIMED FREEZE
Electrical components (Loads) ON OFF
Compressor............................................•
Fan Motor (Air cooled only) and TRIAC ........ ••
Hot Gas Valve ........................................ •
Water Inlet Valve.................................... •
Water Drain Valve .................................. •
P.C.Board Relay 1 Coil .......................... •
P.C.Board Relay 2 & 3 Coil....................•
Water Pump ...........................................•
Contactor Coil ........................................•
P.C.B. Timer...........................................•
Electronic Controls & Sensors ON OFF
Evaporator Sensor .................................•
Condenser Sensor .................................••
Ice Level Control ....................................•
HARVEST (Drain portion - first 15 sec.)
Electrical components (Loads) ON OFF
Compressor............................................•
Fan Motor (Air cooled only)and TRIAC ......... •
Hot Gas Valve ........................................•
Water Inlet Valve....................................•
Water Drain valve...................................•
P.C.Board Relay 1 & 2 Coil....................•
P.C.Board Relay 3 Coil ............................... •
Water Pump ...........................................•
Contactor Coil ........................................•
P.C.B. Timer...........................................•
Electronic Controls & Sensors ON OFF
Evaporator Sensor ................................. •
Condenser Sensor ................................. •
Ice Level Control ....................................•
HARVEST (Water filling portion)
Electrical components (Loads) ON OFF
Compressor............................................•
Fan Motor (Air cooled only)and TRIAC ......... •
Hot Gas Valve ........................................•
Water Inlet Valve....................................•
Water Drain valve...................................•
P.C.Board Relay 1 & 2 Coil....................•
P.C.Board Relay 3 Coil ............................... •
Water Pump ........................................... •
Contactor Coil ........................................•
P.C. Board Timer ...................................•
Electronic Controls & Sensors ON OFF
Evaporator Sensor ................................. •
Condenser Sensor ................................. •
Ice Level Control ....................................•
Page 16

COMPONENTS DESCRIPTION
A. EVAPORATOR TEMPERATURE
SENSOR
The evaporator temperature sensor probe,
locatedincontactwiththeevaporatorserpentine,
detects the dropping of the evaporator tempera-
ture during the freezing cycle and signals it by
supplyingacurrentflowtothemicroprocessorof
P.C. BOARD.
According to the current received, the micro
processor supplies power to the electronic timer
builtinto the P.C. BOARD so that it takes control
of the length of the 2nd phase of freezing cycle.
The length of the timed phase is pre-fixed by the
setting of the keys 1, 2, 3 and 4 of the DIP
SWITCH.
Theactivation of theelectronic timer isindicated
by the lighting up of the RED LED placed in the
front of the P.C. BOARD.
Thislightingupoccures usually in the mid period
of the freezing cycle and signals the switching
fromthe first to thesecond phase of the freezing
cycle.
NOTE.Whenever, after 15minutes from the
beginning of the freezing cycle, the
evaporating temperature have not yet
reached the value of 0 ° C (32 ° F), the
P.C.Board switches OFF the machine with
the BLINKING of RED LED.
B. CONDENSERTEMPERATURESENSOR
The condenser temperature sensor probe,
located within the condenser fins (air cooled
version) or in contact with the tube coil (water
cooledversion) detects the condenser tempe-
raturevariationsandsignalsthembysupplying
current, at low voltage, to the P.C. BOARD.
In the air cooled versions, in relation to the
differentcurrentreceived,themicroprocessorof
theP.C.BOARD supplies,through a TRIAC,the
power at high voltage to the fan motor so to cool
the condenser and to reduce its temperature.
In case the condenser temperature rises and
reaches70°C(160°F) -onaircooledmodels-or
62°C (145°F) - on water cooled models - the
current arriving to the micro processor is such to
causeanimmediateandtotalstopofthemachine
operation.
C. ICE BIN LEVEL LIGHT CONTROL
The electronic ice bin level control, located into
the storage bin, has the function to stop the
operationoftheicemachinewhenthelightbeam
between the light source and the sensor is
interrupted by the ice cubes stored into the bin.
OPERATING CHARACTERISTICS
AC 105
Freeze Cycle
Average Discharge
Pressure A/C: 9.5÷8.5 bar (130÷110 psig)
Average Discharge
Pressure W/C: 10.5÷9.5 bar (150÷135 psig)
Suction Pressure
End Freeze Cycle: 0 ÷0.1 bar (0 ÷1 psig)
REFRIGERANT CHARGE (R 134 A)
Air cooled Water cooled
AC 105 320 gr (11 oz.) 250 gr (9 oz.)
Page 17

Whenthelightbeam isinterruptedtheRED LED
located in the front of the P.C. BOARD goes off;
in case the light beam is constantly interrupted
formore than60seconds,theicemachinestops
with the glowing-up of the 2nd YELLOW LED to
monitor the situation of ice bin full.
The 60 seconds of delay prevent that an ice
scoopmovementortheicedroppingthroughthe
ice chute (interrupting for a while the light beam)
can stop the operation of the unit.
As soon as the ice is scooped out (with the
resumption of the light beam between the two
infraredsensoroficelevelcontrol)theREDLED
islightedupandafter6secondstheicemachine
restarts again with the extinguishing the 2nd
YELLOW LED.
D. P.C. BOARD (Data processor)
TheP.C. BOARD,fitted inits plasticbox located
in the front of the unit, consists of two separated
printed circuits one at high and the other at low
voltage integrated with a program selector, of
two fuses one on power in (100mA) and one on
powerout(16A),offivealignedLEDSmonitoring
the operation of the machine, of two extra
monitoring REDLEDS,ofoneDIPSWITCHwith
tenkeys,of onesmalljumper locatedonits back
side,ofinputterminalsfortheleadsofthesensor
probes and input and output terminals for the
leads of the ice maker electrical wires.
The P.C. BOARD is the brain of the system and
it elaborates, through its micro processor, the
signalsreceivedfromthefoursensorsinorderto
control the operation of the different electrical
componentsoftheicemaker(compressor,water
pump, solenoid valves, etc.).
By turning the program selector it is possible to
put the unit in the following different situations:
CLEANING/RINSING. The water pump is the
only electrical component in operation and it
must be used during the cleaning or the rinsing
procedure of the water system of ice machine.
STAND BY. The unit remain under electrical
powerbutOUTofoperation.Itcanbeusedbythe
service engineer in order to stop the unit during
the service and inspection operations.
IN OPERATION. Theunit is runningthrough the
freezinganddefrostcyclesstoppingautomatically
only at full bin situation.
RE-SET/HI TEMPERATURE. To be selected to
resume the unit operation when the ice maker
shutsoffduetotheinterventionofthecondenser
temperature sensor (too high condensing tem-
perature)or evaporator temperaturesensor (too
high after 15 minutes from the beginning of the
freezing cycle).
The five LEDS, placed in a row in the front of the
P.C. BOARD, monitor the following situations:
GREEN LIGHT
Unit under electrical
power
YELLOW LIGHT
Unitshut-offatfullstorage
bin
RED LIGHT
Unit shut-off due to hi
condensing temperature
RED LIGHT BLINKING
Unit shut-off due to hi
evaporating temperature
YELLOW LIGHT
Unit in freezing cycle
mode
YELLOW LIGHT
Unit in cleaning/rinsing
mode (not appearing in
the front panel)
By means of one small jumper, located on the
back side of the P.C. Board, can be modified
the cut-OUT condensing temperature (safety
temperature)from70°C(160°F)-foraircooled
versions to 62°(145 °F) - for water cooled
versions.
E. DIP SWITCH
The P.C.BOARD which controls the entire
operation of the ice maker, has a DIP SWITCH
with ten switching keys which allow to set up
the micro processor program in order to extend
or to shorten the length of freezing cycle in
relationtothe different modelandversionsofice
machines.
Page 18

LENGTH OF TIMED PORTION OF FREEZING CYCLE ACCORDING TO THE
DIP SWITCH SETTING COMBINATIONS
The DIP SWITCH first four keys setting
determines the length of the 2nd phase of freezing cycle (controlled by the electronic
timer) as detailed in the table B.
TAB. B
Page 19
TheDIPSWITCHkeys5&6settingdetermines
the length of the defrost cycle according to the
size of the cubes (Large or Medium). It is not
possibletomodifythelengthofthedefrostcycle
(factory setting).
The7thD.S.keyisnotusedinthisreleaseofthe
P.C. BOARD.
The8thDIPSWITCHkeyallowstomakearapid
checkupoftheP.C.BOARDoutputconnections
(compressor, water pump, fan motor, water inlet
and hot gas solenoid valves) energizing them in
rapid sequence (2 seconds) one by one.
DURING THE AUTOMATIC OPERATION OF
THE ICE MAKER THIS KEY MUST BE SET IN
OFF POSITION.
ATTENTION. The check up of the
P.C.BOARD output must be performed in
averyshorttimeinordertoavoidfrequent
start and stop (every few seconds) of the
electricalcomponentswhichmaydamage
them specially the compressor.
The 9th key allows the operation of the water
pump even during the defrost cycle, as required
when it is necessary to drain out the remaining
water from the sump.
The 10th key is used to supply power to the
waterpumpforthefirst15secondsofthedefrost
cycle -positionOFF-andforthefirst30seconds
- position ON.
F. WATER SPRAY SYSTEM
Throughitsnozzles,thewaterpumped,issprayed
in each individual cup to be frozen into ice.
It consists of one spray tube wheve are located
several spray nozzles.
G. WATER PUMP
Thewaterpumpoperatescontinuallythroughout
the freezing cycle and on the first 15 or 30
seconds of the defrost cycle so to such the
remaining water from the sump tank (reach in
mineral salts) and drain it out.
During the freezing cycle the pump primes the
water from the sump to the spray system and
through the spray nozzles sprays it into the
invertedcup moldsto befrozen intocrystal clear
ice cubes.
Itisrecommendedthatthepumpmotorbearings
be checked at least every six months.
H. WATER INLET SOLENOID VALVE -
3/4 MALE FITTING
(Water cooled version)
Aspecialwaterinletsolenoidvalvewithoneinlet
andtwooutles(oneforcondenserandthesecond
fortheproduction ofice)is usedon watercooled
version.
An automatic hi pressure control activates the
secondcoilofthewaterinletsolenoidvalvesoto
supply a metered amount of water to the
condenser and drop down its temperature and
pressure.
I. HOT GAS SOLENOID VALVE
The hot gas solenoid valve consists basically in
two parts: the valve body and the valve coil.
Locatedonthehotgasline,thisvalveisenergized
through the micro processor of P.C. BOARD
during the defrost cycle as well as during the
water filling phase.
During the defrost cycle the hot gas valve coil is
activated so to attract the hot gas valve piston in
order to give way to the hot gas discharged from
compressor to flow directly into the evaporator
serpentine to defrost the formed ice cubes.
J. FAN MOTOR (Air cooled version)
The fan motor is controlled through the P.C.
BOARDandtheTRIACbythecondensertempe-
rature sensor. Normally it operates only during
thefreezingcycleto draw coolingairthroughthe