Scotsman NW308 User manual

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SERVICE MANUAL
NW308/508(22inch Model)
NW458/608/1008(30inch Model)
Electronic Modular Cubers
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Part Number : 98020304-00 Version : B

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TABLE OF CONTENTS
Table of contents 1-2
Specifications 3-11
FOR THE INSTALLER
Introduction 12
Storage bin 12
Standard legs 12
Important operating requirements 12
Select location 12
Storage bin 12
Ice machine 13
Air Baffle 13
Stacking instructions 13
FOR THE PLUMBER
Conform to all applicable codesWater inlet 14
Drains 14
For the electrician
Electrical connections 15
Final check list 16
START-UP
Start-up cycle 17
Freezing cycle 17-18
Harvest cycle 18
OPERATION
Refrigeration during freeze 19
Water system 20
Refrigeration system during harvest 21
Water system 21
Control sequence 22
Alarm conditions 22-23
PC Board set up 24
SERVICE SPECIFICATIONS
Component 25
Operating characteristics 25
COMPONENT DESCRIPTION 26-28

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WIRING DIAGRAM
NW 308/508 29
NW 458/608 30
NW 1008 (220V) 31
NW 1008 (380V) 32
SERVICE DIAGNOSIS 33
MAINTENANCE & CLEANING INSTRUCTION
Icemaker 34
Ice storage bin 34
Cabinet exterior 34
Cleaning (Icemaker) 35

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SPECIFICATIONS
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MODULAR CUBER NW 308/508
Ice Making Capacity

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NOTE.To keep your Modular cuber performing at its maximum capacity, it is necessary to
perform periodic maintenance as outlined on page 34&35 of this manual.

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SPECIFICATIONS
MODULAR CUBER NW 308/508

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SPECIFICATIONS
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MODULAR CUBER NW 458
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Ice Making Capacity
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NOTE.To keep your Modular cuber performing at its maximum capacity, it is necessary to
perform periodic maintenance as outlined on page 34&35 of this manual.

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SPECIFICATIONS
MODULAR CUBER NW 458
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SPECIFICATIONS
MODULAR CUBER NW608
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Ice Making Capacity
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NOTE.To keep your Modular cuber performing at its maximum capacity, it is necessary to
perform periodic maintenance as outlined on page 34&35 of this manual.

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SPECIFICATIONS
MODULAR CUBER NW608
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SPECIFICATIONS
MODULAR CUBER NW1008
Ice Making Capacity
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NOTE.To keep your Modular cuber performing at its maximum capacity, it is necessary to
perform periodic maintenance as outlined on page 34&35 of this manual.

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SPECIFICATIONS
MODULAR CUBER NW1008

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FOR THE INSTALLER
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INTRODUCTION
These instructions provide the specifications
and the step-by-step procedures for the
installation, start up and operation for the
SCOTSMAN Model NW 308-508-458-608-
808-1008 Modular Cubers. The Models NW
308-508-458-608-808-1008 Modular Cubers
are quality designed, engineering and
constructed, and are thoroughly tested ices
making systems, providing the utmost in
flexibility to fit the needs of a particular user.
STORAGE BIN
NW 308-508-458-608-808-1008can stack onto
SCOTSMAN bin model NB 193-393-530-948
SCOTSMAN bin.
Refrigerant R404A
Charge per nameplate rating.
STANDARD LEGS: Furnished with storage
bin. Four legs screw into mounting sockets on
cabinet base. Provide 14-17 cm height
including adjustable leveling foot.
IMPORTANT OPERATING REQUIREMENTS
Air Temperature MINIMUM
10 °C(50°F)
MAXIMUM
40°C (100°F)
Water
Temperature 5°C (40°F) 35°C (90°F)
Water Pressures 1 bar gauge 5 bar gauge
Electrical Voltage
Variations Voltage
rating specified on
nameplate
-10% +10%
Extended periods of operation exceeding
these limitations constitute misuse under the
terms of Manufacturer’s Limited Warranty,
resulting in a loss of warranty coverage.
SELECT LOCATION
The first step in installing the equipment is to
select the location. The purchaser of the unit
will have a desired spot in mind, check out that
spot to insure that it is:
- Indoors, in an environment that does not
exceed the air and water temperature
limitations for the equipment.
- That the necessary utilities are available
including the correct voltage electrical power.
- that there be space around the installed
machine for service, 15 cm. minimum left, right,
and rear for air-cooled models.
STORAGE BIN
The Scotsman bins for these units are the NB
393, NB530 and NB948.
Other bins may be available with bin tops to
vary the storage capacity. Lay the bin on its
back, using cardboard from the carton to
support it, screw in the legs.
Stand the bin upright, and correct any possible
small tears in the machine mounting gasket
with food grade silicone sealant.
INSTALLATION NOTE: Allow 15 minimum
space at sides and back for ventilation and
utility connections.

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Page 15
ICE MACHINE
The use of a mechanical lift is recommended
for lifting the uncrated icemaker onto the bin.
Remove front, top and sides panels.
Place the unit directly onto the bin, align it with
the back of the bin. Locate the hardware
package, take out two mounting screws, and
use them to secure the Icemaker to the two
sides of the bin.
See illustration below.
Remove all shipping material as well as the
masking tapes from the ice
Deflector/evaporator cover.
Remove first the ice deflector/evaporator cover
then the masking tape from the ice thickness
sensor.
AIR BAFFLE
Install on the back side of the machine the air
baffle as per instruction provided with it.
STACKING INSTALLATION
To stack a second NW onto the present one,
first remove the top panel from the lower
machine. Add a bead of food grade silicone
sealant to the top edges of the lower units
freezing compartment. Lift the top machine
onto the bottom machine, (the use of a
mechanical lift is recommended for this step).
Align the two machines cabinets, and using
the 2 screw from the top units, hardware
package, fasten the two units together at the
side cabinets.
Then make use of the Stacking Kit KSC 450,
and KSC 1000, to be mounted as per fitting
instructions included in their package,
respectively on NW 458, NW608, NW1008
located in the bottom for proper conveying, of
the ice cubes made by the top unit, into the
storage bin.
With food grade silicone perfectly seal the
edge between the freezing compartment of the
upper machine and of the bottom machine so
to avoid any possible leak of water through the
clearance in between.
(Note: NW 308/508 NOT DESIGNED FOR
STACKING.)

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FOR THE PLUMBER
CONFORM TO ALL APPLICABLE CODES
WATER INLET
AIR-COOLED MODELS: The recommended
water supply is cold water connected to the -
3/4'’ gas - male fitting at the back of the
cabinet. Install a hand valve near the machine
to control the water supply.
1) Plug receptacle
2) Electrical plug
3) Water inlet
4) Shut-off valve
5) Water filter
6) Water inlet line
7) Water outlet line
8) Bin water outlet line
9) Open vented water drain
When choosing the water supply for the NW
Cuber, consideration should be given to:
A. Length of run.
B. Water clarity and purity.
C. Adequate water supply pressures.
Since water is the most important single
ingredient in producing ice you cannot over
emphasize the three items listed above. Low
water pressure, below 1 bar may cause
malfunction, of the icemaker unit. Water
containing excessive minerals will tend to
produce cloudy colored ice cubes, plus scale
build-up on parts in the water system.
Heavily chlorinated water can be controlled
using charcoal or carbon filters.
DRAINS
AIR-COOLED MODELS: There is one 20 mm.
diameter sump drain fitting at the back of the
cabinet. Insulations in high humidity areas is
recommended. The ideal drain receptacle
would be a trapped and vented floor drain.
STORAGE BIN: A separate gravity type drain
needs to be run, similar to the air-cooled sump
drain. Insulation of this drain line is
recommended.

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FOR THE ELECTRICIAN
ELECTRICAL CONNECTIONS
The unit comes equipped with an electrical
cord for power supply. The lead wires must be
connected to an electrical plug that
corresponds to the local electrical codes and
requirements or to a separate two poles
disconnect box with opening to the contacts of
about 3 millimeters. The disconnect box
should be placed close to the selected ice
maker location to be easily and prompt
reached.
Undersized wiring or improperly installed
electrical circuit will result in major problems
and malfunctions.Voltage variations should not
exceed ten percent.
NOTE:
All SCOTSMAN Cubers require a neutral
wire and a solid earth ground wire to prevent
possible severe Electrical Shock Injury to
individuals or extensive damage to
equipments.
IMPORTANT - All plumbing and
electrical connections must be made
by licensed plumbers and electricians,
this one must follow the electrical
specifications printed on the ice maker
nameplate.

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FINAL CHECK LIST
1.Is the cabinet/bin level?
2. Is the cuber in a location where ambient
temperatures are a minimum of 10℃(50℉) all
year around and to not exceed a maximum of
40℃. (100℉.)
.3. Is there at least a 15 cm. clearance behind
and around the cabinet for all connections and
for proper air circulation?
4. Have all electrical and piping connections
been made?
5. Has the electrical power supply wiring been
properly connected and the voltage tested and
checked against the nameplate rating? Has
the unit properly grounded?
6. Is the water supply line shutoff valve
installed and opened and has the inlet water
supply pressure been checked to insure a
minimum of1 bar without exceeding a
maximum of 5 bar.
7. Have the compressor hold down bolts been
checked to be sure the compressor is snug on
the mounting pads.
8.Check all refrigerant lines and conduit lines
to against vibration and possible failure.
9. Has the cuber and the bin been wiped clean
with clean damp cloths?
10. Has the owner/user been given the user
manual and instructed on how to operate the
icemaker and the importance of periodic
maintenance?
11. Has the owner/user been given the name
and telephone number of the authorized
SCOTSMAN distributor or service agency
serving him?
12. Has the manufacturer’s registration card
been properly filled out?
Check for correct Model and serial numbers
from nameplate, and then mail the completed
card to the manufactured.
TYPICAL STACKING INSTALLATION
KIT STACKING KSC 450: TO STACK 2 NW 458
KIT STACKING KSC 450: TO STACK 2 NW608
KIT STACKING KSC 1000: TO STACK 2 NW 1008
(NW308/508 NOT DESIGNED FOR STACKING)

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START-UP
START-UP CYCLE
1.Open the water tap/valve and switch ON the
power on the electrical supply line.
2.The models NW308-508-458-
608-808 enter in the Start Up
cycle with the PC Board
energized, andNW1008 enter in
90 minutes delay time controlled
by PC Board, The LED of ICE
MAKING blinking slow.
In Start Up cycle the LED of ICE
MAKING and BIN FULL are
energized, blinking slow3
minutes for water system clean,
then ICE MAKING blinking fast
40 second for pressure balance.
3. During the start up cycle the components in
operation are:
• Hot Gas valve
• Water Drain Valve
• Water Inlet Valve
• Water Pump
FREEZING CYCLE
1. After the start up cycle the machine enters
directly into the freezing cycle with the
following components energized:
• Water Inlet valve
• Compressor
• Fan motor.
2. The LED energized are:
• Machine under power (steady)
• Machine in ICE MAKING (steady)
3. Water is coming into the water through the
Water Inlet Solenoid Valve till the water
reservoir if filled up to the maximum level
controlled by a Water Level Sensor.
4. 40 seconds later, the Water Pump starts up.
5. After few minutes (3-5) from the start up of
the freezing cycle, the Water Inlet Solenoid
Valve is activated again for few seconds to
refill the water reservoir up to the maximum
level so to reduce any possibility of slush ice
formation.
6.In the meantime the condenser sensor starts
to transmit the current to the PC Board
keeping in operation the Fan Motor in ON-OFF
mode or continuously according to the
condenser temperature.
7. The machine remains in the freezing cycle
with the ice that become thicker till the two
metal plates of the Ice Thickness Sensor are
covered by the water cascading through the
front surface of the ice plate.
8. When the Power is transmitted back to the
PC Board continuously through the metal
plates of the Ice Thickness Sensor for more
than 6", the machine enters in the Pre-Harvest
or directly into the Harvest Cycle mode
according to:
• FAN MOTOR IN ON-OFF MODE DURING
Rise up the cutting temperature of the
condenser sensor to38℃ (fan motor off) and
extend the length of freezing cycle by 30"
more the going to harvest cycle.
• FAN MOTOR ALWAYS IN OPERATION
Go straight to the harvest cycle.
NOTE:
Model NW 1008 has a crankcase heater in
the compressor. When the main power to the
machine is switched ON, there is a time
delay of 90 minutes during which only the
compressor heater is energized with Green
ICE Making LED Blinking slowly.
However, if the ambient temperature is
higher than 25*C (77*F), PC Board will
automatically bypass this delay.
This time delay can also be bypass by
pressing the bypass switch located at the
back of the machine.
NOTE: Do not remove the evaporator
deflector cover as it will cause the switching
off of the machine at "STORAGE BIN FULL".

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9. First freezing time will range between 15
and 20 minutes. Longer time for temperature
above 25℃ and shorter time required when
temperature are below25℃.Average complete
cycle time is about 22 min.
HARVEST CYCLE
1. During the harvest cycle the components in
operation are:
• Hot Gas valve
• Water Drain/Purge Valve
• Water Pump (According DIP Switch #6&#7)
• Compressor
And both
• Machine under Power
• Machine in Operation
2. After beginning of Harvest Cycle, Purge
Valve will according DIP Switch (#6&#7) setup
to purge water, 20” after the Purge Valve open,
the Water Inlet Solenoid Valve is energized for
10 seconds only in order to have a short flush
of fresh water into the sump while the Water
Pump and Purge valve are still in operation.
3. The Fan Motor remains in OFF mode
unless the Condenser Sensor probe rise up to
more then 38℃ (same set up as per end of
freezing cycle).
4. When the ice plate is falling down from the
evaporator, the magnetic switch is activated
for a while providing the signal to the PC
Board to restart a new freezing cycle.
5. Observe first ice cube harvest and check
size of ice cubes; if an adjustment is required
thread down or out screw NO.1 as shown on
below illustration.
This screw position determines the distance
between the sensor reeds and the egg-crate
evaporator thus keeping the ice cube at a
proper thickness.
6. Observe second and third cube harvest.
Check if size and shape combination is correct.
In areas where extreme problem water
conditions exist, filtering or purifying
equipment is recommended.
7. Check operation of magnetic switch
controlling it by keeping open the bottom end
of plastic deflector for more than 30 seconds.
The machine must switch off at storage bin full.
Release the plastic deflector. The machine
should restart in the freezing cycle mode
within few seconds going through a 3' delay
time.
8. Place again all cabinet panels and screws
previously removed.
9. Thoroughly explain to owner/user the
significant specifications of the ice maker
startup, reset and operation, going through the
procedures in the operating instructions.
Answer all questions about the ice maker by
the owner and inform the owner himself of the
name and telephone number of the authorized
service agency serving him.
NOTE: To assure a correct operation of the
machine the water must have a minimum
electric conductivity of 20μs.
NOTE: If water used is too soft,
"demineralized" the ice thickness sensor might
not be able to sense the water on its reeds,
thereby it will not switch the unit on harvest
cycle.
A safety system built in the P.C. Board
switches the unit on harvest cycle whenever
the freezing period gets longer than 30’ or 40’.
NOTE: This type of machine produce an "ICE
PLATE" that breaks when falls down into the
storage bin. Setting the ice thickness sensor in
order to have single ice cubes may cause
malfunction of the machine.

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Page 19
OPERATION
FREEZE CYCLE
REFRIGERATION SYSTEM SCHEMATIC
REFRIGERATION DURING FREEZE:
This ice machine employs either air or water
as a condensing media, the refrigeration
system for either one is a follows:
At the hermetic compressor, Refrigerant is
compressed into a high temperature, high
pressure gas.
The gas moves through the discharge line into
the condenser, air or water-cooled. If air-
cooled, the discharge pressure will change
with the heat load and the ambient air
temperature.
If water-cooled, the discharge pressure is
controlled by the amount of water flowing
through the condenser - which is determined
by the water regulating valve.
After the gas is cooled in the condenser,
giving up much of its heat, the gas condenses
into a high pressure liquid. This liquid travels
through the liquid line to the metering device,
a thermostatic expansion valve.
The thermostatic expansion valve meters how
much liquid refrigerant is to be allowed into the
evaporator section of the refrigeration system.
This is determined by the temperature of the
TXV sensing bulb, located on the suction line
manifold, at the outlet of the evaporator.
If the bulb senses a warm suction line, more
refrigerant is allowed into the evaporator,
(common at the beginning of the freeze cycle)
and when the temperature begins to fall, less
refrigerant is allowed through.
This is why the suction side gauge pressure
will decline throughout the freeze cycle. At the
evaporator, the liquid refrigerant released from
high pressure, boils off in the low pressure
environment and absorbs heat, thus cooling
the evaporator surface and anything near it,
such as water.
The low pressure refrigerant vapor then is
forced through the heat exchanger where any
excess liquid refrigerant boils-off, allowing only
refrigerant vapor to enter the compressor
suction tube, where it is recompressed into
high pressure, high temperature gas again
and the cycle repeats.