Scotsman NW458 User manual

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SERVICE MANUAL
NW458
NW608
NW1008
Electronic Modular Cubers

98020303-00 Version A

2

TABLE OF CONTENTS
Table of contents
Specifications 2-3 4-9
FOR THE INSTALLER
Introduction 10
Storage bin 10
Standard legs 10
Important operating requirements 10
Select location 11
Storage bin 11
Ice machine 11
Stacking instructions 12
FOR THE PLUMBER
Conform to all applicable codes
Water inlet 13
Drains 13
For the electrician
Electrical connections 14
Final check list 15
START-UP
Start-up cycle 16
Freezing cycle 16
Harvest cycle 17
OPERATION
Refrigeration during freeze 18
Water system 19
Refrigeration system during harvest 20
Water system 20
Control sequence 20
Alarm conditions 21
PC Board set up 22
SERVICE SPECIFICATIONS
Component 23
Operating characteristics 23
COMPONENT DESCRIPTION
Component description 24-26

3

WIRING DIAGRAM
NW 458/608 27
NW 1008 28
SERVICE DIAGNOSIS
Service diagnosis 29
MAINTENANCE & CLEANING INSTRUCTION
Icemaker 30
Ice storage bin 30
Cabinet exterior 30
Cleaning (Icemaker) 30-31

4

SPECIFICATIONS

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 29 of this manual.

5

SPECIFICATIONS
MODULAR CUBER NW 458
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Air Cooled
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6


SPECIFICATIONS
MODULAR CUBER NW 608

Ice Making Capacity



NOTE.To keep your Modular cuber performing at its maximum capacity, it is necessary to perform periodic
maintenance as outlined on page 29 of this manual.

7


SPECIFICATIONS
MODULAR CUBER NW 608

Air Cooled


8

SPECIFICATIONS
MODULAR CUBER NW 1008
Ice Making Capacity

NOTE.To keep your Modular cuber performing at its maximum capacity, it is necessary to perform periodic
maintenance as outlined on page 29 of this manual.

9

SPECIFICATIONS
MODULAR CUBER NW 1008
Air Cooled

10

FOR THE INSTALLER

INTRODUCTION
These instructions provide the specifications
and the step-by-step procedures for the
installation, start up and operation for the
SCOTSMAN Model NW 458-608-1008
Modular Cubers. The Models NW 458-608-
1008 Modular Cubers are quality designed,
engineering and constructed, and are
thoroughly tested ice making systems,
providing the utmost in flexibility to fit the
needs of a particular user.
STORAGE BIN
NW 458 608 1008 stack onto SCOTSMAN bin
model NB 393/530/948.
Refrigerant R 404 A
Charge per nameplate rating.
STANDARD LEGS: Furnished with storage
bin. Four legs screw into mounting sockets on
cabinet base. Provide 18.5 cm. (7’’) minimum
heights 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.
INSTALLATION NOTE: Allow 15 cm minimum
space at sides and back for ventilation and utility
connections.


SE
L
Th
e
sel
e
will
sp
o
- i
n
ex
c
limi
- t
h
incl
- t
h
ma
c
an
d
ST
O
Th
e
39
3
Ot
h
var
y
ba
c
su
p
Sta
sm
a
wit
h
IC
E
Th
e
for
Re
m
Pla
the
pa
c
us
e
sid
e
Se
e
Re
m
ma
s
De
f
L
ECT LO
C
e
first ste
p
e
ct the lo
c
have a d
e
o
t to insur
e
n
doors, in
c
eed the
tations for
h
at the
n
uding the
c
h
at there
c
hine for
s
d
rear for
a
O
RAGE B
e
Scotsma
3
, NB530
a
h
er bins
m
y
the stor
a
c
k, using
p
port it, sc
r
nd the bin
a
ll tears i
n
h
food gra
d
E
MACHIN
e
use of a
lifting the
m
ove fron
t
ce the uni
t
back of
c
kage, tak
e
e
them to
e
s of the b
e
illustrati
o
m
ove all
s
s
king
f
lector/eva
C
ATION
p
in installi
c
ation. Th
e
e
sired spot
e
that it is:
an envir
o
air an
d
the equip
m
n
ecessary
c
orrect vo
l
be spac
e
s
ervice, 15
a
i
r
-cooled
m
IN
n bins for
a
nd NB94
8
m
ay be av
a
a
ge capa
c
cardboar
d
r
ew in the
l
upright, a
n
the ma
c
d
e silicone
E
mechani
c
uncrated
t
, top and
s
t
directly o
the bin.
e
out two
secure th
e
in.
o
n below.
s
hipping
m
tapes
porator co
v
ng the eq
u
e
purchas
e
in mind,
c
o
nment t
h
d
water
m
ent.
utilities
a
l
tage elect
r
e
around
cm. mini
m
m
odels.
these uni
t
8
.
a
ilable wit
h
c
ity. Lay t
h
d
from t
h
l
egs.
nd correct
c
hine mo
u
sealant.
c
al lift is r
e
icemaker
s
ides pan
e
nto the bi
n
Locate t
h
mounting
e
Icemak
e
m
aterial a
s
from
v
er.
u
ipment i
s
e
r of the
u
c
heck out t
h
at does
temperat
u
a
re availa
r
ical powe
the instal
m
um left, ri
g
t
s are the
h
bin top
s
h
e bin on
h
e carton
any possi
u
nting gas
e
commen
d
onto the
b
e
ls.
n
, align it
w
h
e hardw
a
screws,
a
e
r to the
t
s
well as
t
the
11
s
to
u
nit
hat
not
u
re
ble
r.
led
g
ht,
NB
s
to
its
to
ble
ket
d
ed
b
in.
w
ith
a
re
a
nd
t
wo
t
he
ice
R
e
th
e
se
e
move firs
t
e
n the ma
nsor.
t
the ice d
e
sking tap
e
e
flector/ev
a
e
from the
a
porator c
o
ice thick
n
o
ver
n
ess

12
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Page 15
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.

13
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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.
dia sump drain fitting at the back of the cabinet.
Insulations in high humidity areas is recom-
mended. 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.

14
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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.

15
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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 C (50-de-
grees F.) all year around and to not exceed a
maximum of 40 C. (100 F.)
.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 of 1 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 gard 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, 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 NW 608
KIT STACKING KSC 1000: TO STACK 2 NW 1008

16

START-UP
START-UP CYCLE
1. Open the water tap/valve and switch ON the
power on the electrical supply line.
2. The models NW 458, 608
enter in the Start Up mode with
the PC Board energized as well
as the Green LED of the
machine under power while the
models NW 1008 enter in 90
minutes delay time controlled by
a special Start-up Delay PC
Board.
The Green LED of machine in
operation is energized too,
blinking fast for 40 seconds.
3. During the Start Up cycle the
components in operation are:
• Hot gas valve
• Water Drain 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 (in continuous operation for the
first 3 minutes).
2. The LED energized are:
• Machine under power
• Machine in operation (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. 30 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 re-
fill 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
THE PREVIOUS FREEZING CYCLE
RISE UP THE CUT IN TEMPERATURE OF
THE CONDENSER SENSOR TO 38 C (FAN
MOTOR OFF) AND EXTEND THE LENGTH
OF FREEZING CYCLE BY 30" MORE THEN
GO INTO HARVEST CYCLE
• FAN MOTOR ALWAYS IN OPERATION
DURING THE PREVIOUS FREEZING CYCLE
GO STRAIGHT TO THE HARVEST CYCLE
9. First freezing time will range between 15
and 20 minutes. Longer time for temperature
NOTE: Do not remove the evaporator
deflector cover as it will cause the switching
off of the machine at "STORAGE BIN
FULL".
NOTE: The models NW 1008 is equipped
with a compressor crankcase heater and a
Start up Delay PC Board set up at 90
minutes. During the first 90 minutes only
the compressor crankcase heater is
energized warning up the compressor.

17

above 25℃and shorter time required when
temperature are below 25 ℃. 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 for the first 40"
• Compressor
and both
• Machine Under Power
• Machine in Operation
2. 30 seconds after the beginning of the
Harvest Cycle, 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 is 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 start-
up, 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
electrical conductivity of 20 us.
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.


O
P
RE
F
Thi
s
co
n
eit
h
A
t
co
m
pre
Th
e
the
co
o
wit
h
te
m
If
w
co
n
thr
o
by
t
A
ft
e
givi
int
o
thr
o
a t
h
Th
e
mu
c
P
ERATI
O
F
RIGERA
T
s
ice ma
n
densing
m
h
er one is
a
the herm
m
pressed
ssure gas
.
e
gas mov
e
condens
e
o
led, the
d
h
the he
m
perature.
w
ate
r
-cool
n
trolled b
y
o
ugh the
c
t
he water
r
e
r the ga
ng up mu
c
o
a high p
o
ugh the li
h
ermostati
c
e
thermos
t
c
h liquid r
e
O
N
T
ION DU
R
chine em
m
edia, the
a
follows:
etic com
p
into a h
.
e
s throug
h
e
r, air o
r
d
ischarge
at load
ed, the
d
y
the am
o
c
ondenser
r
egulating
v
s is cool
c
h of its h
e
ressure li
q
quid line
t
c
expansi
o
t
atic expa
n
e
frigerant i
REF
R
R
ING FRE
E
ploys eit
h
refrigerati
o
p
ressor,
R
igh temp
e
h
the disch
r
wate
r
-c
o
pressure
and the
d
ischarge
o
unt of
w
- which i
s
v
alve.
ed in th
e
e
at, the g
a
q
uid. This
t
o the me
t
o
n valve.
n
sion valv
e
s to be all
o
FR
E
R
IGERATI
O
E
ZE:
h
er air a
s
o
n system
R
efrigerant
e
rature, h
arge line i
o
oled. If
a
will cha
n
ambient
pressure
w
ater flow
s
determi
n
e
conden
s
a
s conden
s
liquid tra
v
t
ering devi
e
meters h
o
wed into
t
18
E
EZE CY
C
O
N SYST
E
s
a
for
is
igh
nto
a
i
r
-
n
ge
air
is
ing
n
ed
s
er,
s
es
v
els
ce,
ow
t
he
e
v
T
h
T
X
m
a
If
t
re
f
(c
o
a
n
re
f
T
h
wi
l
e
v
hi
g
e
n
th
e
su
T
h
fo
r
e
x
re
f
su
hi
g
a
n
C
LE
E
M SCHE
M
v
aporator
s
h
is is dete
r
X
V sensin
g
a
nifold, at
t
t
he bulb
s
f
rigerant i
o
mmon at
n
d when t
h
f
rigerant i
s
h
is is why
l
l decline t
v
aporator,
t
g
h pressu
n
vironment
e
evapora
ch as wat
e
h
e low pr
e
r
ced throu
g
x
cess liqui
d
f
rigerant
v
ction tub
e
g
h pressu
n
d the cycl
e
M
ATIC
s
ection of t
h
r
mined by
g
bulb, lo
c
t
he outlet
o
s
enses a
w
s allowe
d
the begin
n
h
e temper
a
s
allowed t
h
the sucti
o
hroughou
t
t
he liquid
r
re, boils
o
and abs
o
tor surfac
e
e
r.
e
ssure re
f
g
h the he
a
d
refrigera
n
v
apor to
e
, where
i
re, high
t
e
repeats.
P
h
e refrige
r
the temp
c
ated on t
h
o
f the eva
p
w
arm suct
d
into th
e
n
ing of th
e
a
ture begi
n
h
rough.
o
n side g
a
t
the freez
e
r
efrigerant
o
ff in the
o
rbs heat
,
e
and an
y
f
rigerant
v
a
t exchan
g
n
t boils-off
enter th
e
i
t is reco
m
t
emperatu
P
age 19
ation syst
e
erature of
h
e suction
p
orator.
ion line,
m
e
evapor
a
e
freeze c
y
n
s to fall,
a
uge pres
s
e
cycle. A
t
released
f
low pres
s
,
thus co
o
y
thing ne
a
v
apor the
n
g
er where
, allowing
o
e
compre
s
m
pressed
re gas a
g
e
m.
the
line
m
ore
a
tor,
y
cle)
less
s
ure
t
the
f
rom
s
ure
o
ling
a
r it,
n
is
any
o
nly
s
sor
into
g
ain

19

FREEZE CYCLE
WATER SYSTEM
A combination of a solenoid water inlet valve
with a water level sensor is used to control the
level of the water into the reservoir/sump.
A pump, running continuously, after the first
30" of freezing cycle, forces the water to the
top of the evaporator, where it is distributed
through a water tube and then cascades down
the evaporator surface by gravity. As it flows
across the refrigerated evaporator, some of
the water will be chilled enough to change
form, turn to ice, and stay frozen onto the
evaporator cells. Most of the water returns to
the reservoir, to be sucked back into the pump,
and re-pumped over the evaporator.

20

HARVEST (DEFROST) CYCLE
REFRIGERATION SYSTEM SCHEMATIC
REFRIGERATION SYSTEM DURING
HARVEST
The refrigeration system performs the harvest
of ice by use of a hot gas bypass valve. When
the time comes to de-ice the evaporators, the
hot gas valve is energized, and the high
temperature, high pressure gas bypasses the
condenser, and is allowed directly into the
evaporator. The high pressure gas is cooled
by the cold evaporator so it condenses into a
liquid, giving up its heat as it does so. This
heat warms the evaporator and the ice frozen
onto the evaporator surface melts, releasing
the frozen cubes. Ice then falls by gravity into
the storage bin.
The liquid refrigerant goes through the suction
line into the heat exchanger where it boils-off
so that only refrigerant vapor is drawn into the
suction tube of the compressor.
WATER SYSTEM
During the harvest cycle, the electric water
drain valve is energized thereby opening the
drain line.
All water remained in the reservoir at the end
of freezing cycle is pumped-out, to the waste,
through the water solenoid and drain line
during the first 40 seconds of the defrost cycle
eliminating any possible build-up and
accumulation of minerals concentration and
impurities in the water reservoir.
The water inlet valve is energized during the
last 10" of the operation of the water pump so
to rinse the water tank with new fresh water.
When the released ice cubes drop into the bin,
they open-up for a fraction of a seconds the
bottom end of plastic deflector.
This deflector swinging motion is enough to
reset the contact of the magnetic switch which
- via electronic control board de-energizes the
water drain valve allowing the unit to initiate a
new freezing cycle. The harvest cycle lasts
about 1.5-2 minutes.
CONTROL SEQUENCE
At the start of the freezing cycle, the contacts
of the magnetic switch mechanically operated
by the actuator plate of the deflector cover are
closed, thereby - via electronic control board -