Scotsman NM1250 Installation Manual
INTRODUCTION
NM1250
To the owner or user: The service manual you
are reading is intended to provide you, and the
maintenance or service technician, with the
informtion needed to install, start up, clean,
maintain, and service this ice system.
The NM1250 is a modular ice system that
produces up to 1000 lbs. of nugget ice in 24
hours at 90
0
F. air and 700F. water.
It features: front service for the evaporator,
gearmotor, control box, water reservoir and
bincontrol; stackability by use of kit
KSTACK30; electronic circuitry for monitoring
ice and water level; a thermostatic expansion
valve; and R502 as the refrigerant.
TABLE OF CONTENTS
For the Installer
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Stacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
For the Plumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
For the Electrician . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Final Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Component Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Electrical Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Maintenance & Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Removal and Replacement
Water Reservoir & Bin Control . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Thrust Bearing and Breaker . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Auger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Water Seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Evaporator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Gearmotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Electronic Tester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Parts Lists and Wiring Diagrams are located in the center of this manual, printed on yellow
paper.
February, 1989
Page 1
BASIC
ELECTRICAL
208-230/60/1
208-230/60/1
208-230/60/3
208-230/60/3
MINIMUM
CIRCUIT
AMPACITY+
9.8
9.0
n/a
n/a
NM1250
FOR THE INSTALLER
The NM1250 is designed to fit the following
Scotsman storage bins:
B590 and extensions (with bin top KBT18)
HTB500 or BH500
BH800 using bin top KBT15
BH1000 using bin top KBT16
The normal finish for the machine is
enamel-sandalwood.
An optional stainless steel panel kit
(SPKCMD-1) may be added to the machine.
When installing a new system, check to be
sure that you have everything you need
before beginning:
Correct Bin
Correct Ice Machine
Correct Bin Top (if required)
All kits, legs, and information required for the
specific job.
SPECIFICATIONS: ICEMAKER
MODEL
NM1250AE-32A
NM1250WE-32A
NM1250AE-3A
NM1250WE-3A
+ Minimum Circuit Ampacity is used to determine wire size and type per National Electric Code.
DIMENSIONS
(without bin)
H" x W" x D"
27 x 30 x 24
same
same
same
90/70 ICE
CAPACITY
1000 lbs.
same
same
same
COMP.
H.P.
1.75
same
same
same
February, 1989
Page 2
ICE
TYPE
NUGGET
same
same
same
MAX
FUSE
SIZE
20
20
n/a
n/a
FOR THE INSTALLER: Environmental Limitations
Typical Storage Bin, BH800
Water Limitations
An ice machine is a food manufacturing plant;
it takes a raw material, water, and turns it into
a food product, ice. The purity of the water is
very important in obtaining pure ice and in
maximizing product life. This section is not
intended as a complete resource for water
questions, but it does offer these general
recommendations:
1. Filter the water used to produce ice. That is
the water going to the "potable" water
connection. Water filters vary in ability and
function. Install one that filters out suspended
solids to a dimension of 5 microns or smaller.
The finer the filter the better, but finer filters
will clog sooner than course ones. It may be
necessary to add a course filter ahead of the
fine filter to prolong filter life.
2. Check with a water treatment specialist for
a water test, and recommendations regarding
filters and treatment.
1.19"
DRAIN
3/4"
FPT
21.0"
BACK VIEW
NM1250
Installation Limitations:
This ice system is designed to be installed
indoors, in a controlled environment:
Min Max
Air Temperature 50
Water Temperature 40
0
F 1000F
0
F 1000F
Water Pressure 20 psi 80 psi
Voltage -5% +10%
(Compared to the nameplate)
Operating the machine outside of the
limitations is misuse and can void the warranty.
Scotsman Ice Systems are designed and
manufactured with the highest regard for
safety and performance. They meet or
exceed the standards of UL, NSF, and CSA.
Scotsman assumes no liability or responsibility
of any kind for products manufactured by
Scotsman that have been altered in any way,
including the use of any part and/or other
components not specifically approved by
Scotsman.
Scotsman reserves the right to make design
changes and/or improvements at any time.
Specifications and design are subject to
change without notice.
February, 1989
Page 3
LEVEL THE
ASSEMBLY
NM1250
FOR THE INSTALLER
Location
After uncrating and inspection, the
unit is ready for installation. It is
important that the machine be
installed in a location where it has
enough space around it to be
accessible for service, and minimum
of 6" be allowed to the left, right and
top for air circulation on air cooled
models. Try to avoid hot, dirty and
crowded locations. Be sure that the
location for the machine is within the
limitations described on page 3.
Storage Bin
Tip the storage bin on its back, using
parts of the carton to protect the
exterior finish. Install the legs into
the threaded holes in the bottom of
the bin. Turn the leg levelers all the
way in preparation for leveling later.
Return the bin to the upright
position, remove paper covering the
bin gasket.
Install bin top if required.
Note: Do not push bin into position,
but lift it there. Pushing a bin,
especially one with ice in it, can
cause damage to the legs and the
leg mounts.
Ice Maker
The machine is heavy, so the use of
a mechanical lift is recommended for
lifting the machine high enough to
install on top of the bin. After the unit
is placed on the bin, line it up so it is
even with the back, left, and right
sides. Secure the machine to the bin
with the hardware provided with the
machine.
GASKET
FASTEN THE MACHINE
TO THE BIN WITH THE
HARDWARE SUPPLIED
WITH THE ICE MAKER
February, 1989
Page 4
FOR THE INSTALLER: Stacking
NM1250
KSNM30 STACKING KIT INSTRUCTIONS
The purpose of the this kit is to connect the ice
level controls from the bottom machine to an
additional circuit board so that they control both
machines.
////////////////////////////////WARNING/////////////////////////////////
Disconnect electrical power to both machines
while installing this kit.
///////////////////////////////////////////////////////////////////////////////////
1. Stack the two unit’s by removing the top panel
from the lower unit (assumed to be already
installed on the bin) and, using a mechanical lift,
place the upper unit onto the lower one. Secure
the two units together with the hardware (straps
and bolts) provided with the upper unit.
2. Remove the front panels from both units.
3. From below the upper unit base, insert the ice
chute extension (from the kit) into the upper unit’s
ice chute.
4. Remove the lower unit’s existing ice chute
cover, and replace it with the one from the kit.
Transfer the spout switch assembly to the new
cover:
A. Remove microswitch.
B. Pull o-ring out from between chute cover and
spout switch assembly, push spout switch
assembly through chute cover. Reverse to
reassemble on the new cover.
5. Pull the chute extension down and slide it into
the lower unit’s new ice chute cover.
6. Remove the control box covers from both units.
LOWER UNIT:
7. Remove the two lower control box mounting
screws and use them to mount the stacking kit
circuit board (upper flange only) in between the
control box and the bulkhead panel.
8. Remove the bushing that the ice level sensor
wires pass through from the control box.
9. Unplug the "photo trans" ice level sensor from
the connection on the ice machine circuit board,
pull it out of the control box, and plug it into the
"photo stack" plug on the stacking kit circuit board.
10. Unplug the "LED" ice level sensor from the ice
machine circuit board, pull it out of the control box,
and plug it into the "LED Stack" connection on the
stacking kit circuit board.
11. One by one, pass all of the wires from the
stacking kit circuit board through the hole in the
control box, and reinstall the bushing removed in
step 8, then:
A. Plug the two pin plug onto the ice machine
circuit board socket marked "LED" (CX2).
B. Plug the 3 pin plug onto the ice machine circuit
board socket marked "Photo Trans" (CX4).
12. Unplug the wire harness connecting the
transformer to the ice machine circuit board, and
remove from the machine, then:
A. Plug the 4 pin plug into the ice machine circuit
board socket marked "power" (CX1).
B. Connect the two free wires from the 4 pin plug
(connected above) to the transformer (marked
"load").
13. Plug the last wire from the stacking kit circuit
board into the "Remote Lamp" (located in the
upper left corner of the board) plug on the ice
machine circuit board.
UPPER UNIT:
14. Unplug, but leave in the control box the "photo
trans" and "LED" ice level sensor wires. Leave in
place on ice chute.
15. There are two different wires in the kit separate
from the circuit board; one has a three pin
connector and the other has a two pin connector.
Find the one with the three pins, and insert the big
end onto "photo trans" on the ice machine circuit
board. Pass the other (smaller) end of the wire
through the bushing in the control box, and through
the bushing beside the ice chute in the base of the
upper unit.
16. Find the wire with the two pin connector, and
insert the bigger two pin plug onto "LED" on the ice
machine control board and pass the other (smaller)
end through the bushing in the control box, and
through the bushing beside the ice chute in the
base of the upper unit (as above).
BACK TO LOWER UNIT:
17. Next, connect the wires from the upper unit to
the stacking kit circuit board: plug the two pin
connector onto the two pin plug, and the three pin
connector onto the three pin plug.
This completes the assembly. Reconnect power
and after 10-15 seconds the units should start;
bottom unit first. To check shut off: in the lower unit
pull left on the front ice level sensor and cover the
open end: the bottom unit’s compressor should
stop after about 10-15 seconds, then the top unit’s
compressor will stop. Within a few minutes the
auger motors will also stop. Replace the front ice
level sensor, be certain that it is in it’s "centered
and locked" position.
Replace all covers and panels.
February, 1989
Page 5
Use only 3/4" rigid tubing.
NM1250
FOR THE PLUMBER
CONFORM TO ALL APPLICABLE CODES
Water Inlet
Air Cooled Models: The recommended water
supply is cold water. Use 3/8" O.D. copper
tubing, connect to the 3/8" male flare at the
back of the cabinet. Install a hand valve near
the machine to control the water supply.
WATER
COOLED
WATER INLET
HAND SHUT
OFF VALVE
CONNECT TO
COLD WATER
3/8" FLARE
Drains
Air Cooled Models: There is one 3/4" FPT
drain at the back of the cabinet, the drain line
is of the gravity type, and 1/4 inch per foot fall
is an acceptable pitch for the drain tubing.
There should be a vent at the highest point of
the drain line, and the ideal drain receptacle
would be a trapped and vented floor drain.
FILTER, FIELD
INSTALLED
(OPTIONAL)
Water Cooled Models: A separate 3/8" O.D.
copper line is recommended, with a separate
hand valve to control it. It is connected to a
3/8" FPT condenser inlet at the back of the
cabinet. The water pressure to all lines must
always be above 20 psig, and below 120 psig.
ICE MAKER
DRAIN
3/4" FPT
BIN DRAIN
3/4" FPT
Water Cooled Models: In addition to the
above mentioned drain, a separate condenser
drain must be installed. Connect it to the 1/2"
condenser drain connection at the back of the
cabinet.
Storage Bin: A separate gravity type drain
needs to be run, similar to the air cooled drain.
Insulation of this drain line is recommended.
February, 1989
Page 6
FOR THE ELECTRICIAN
ICE MAKER
JUNCTION BOX
CONFORM TO ALL APPLICABLE CODES
NM1250
The electrical power to the unit is supplied
through the junction box at the rear of the
machine.
Check the nameplate (located on the back
panel) for the voltage requirements, and for
the minimum circuit ampacity. The machine
requires a solid chassis to earth ground wire.
The ice maker should be connected to its own
electrical circuit so it would be individually
fused.
POWER
SUPPLY
Voltage variation must remain within design
limitations, even under starting conditions.
All external wiring must conform to
national, state, and local electrical codes.
The use of a licensed electrician is
required to perform the electrical
installation.
THIS UNIT MUST BE
GROUNDED
February, 1989
Page 7
NM1250
FOR THE INSTALLER: Final Check List
1. Is the ice system installed indoors in
a location where the air and water
temperatures are controlled, and where
they do not exceed the design
limitations?
2. Is there an electrical service
disconnect within sight of the installed
machine? Has the voltage been
checked, and compared to nameplate
requirements?
3. Have all the plumbing connections
been made and checked for leaks?
POWER
SUPPLY?
PLUMBING?
LEVELED?
4. Has the machine and bin been
leveled?
5. Is there a minimum of 6" clearance at
the rear, left, and right of the machine
for proper service access and air
circulation?
6. Is the water pressure a minimum of
20 psig?
7. Has the machine been secured to the
bin?
8. If stacked, has the stacking kit been
installed?
9. Is there a water shut off valve
installed near the machine?
MACHINE
SECURE TO
BIN?
DRAINS?
10. Have the shipping blocks been
removed from under the gearmotor, the
top of the ice chute, and from between
the gearmotor and the right side panel?
February, 1989
Page 8
START UP
NM1250
Pre-Start Inspection
1. Remove the front, and left side service
panels.
2. Check that the styrofoam shipping blocks
under the gearmotor, on top of the ice
discharge chute, and between the gearmotor
and the right side panel have been removed.
Start Up
1. Go through the prestart inspection.
2. Open the hand valve, observe that water
enters the water reservoir, fills the tube from
the reservoir to the evaporator, and then shuts
off. Check for leaks.
3. Switch the master switch on.
The electrical start up sequence is now on
automatic.
A. There should be a short (15 second) delay
before the gearmotor starts.
B. After the gearmotor starts, the compressor
will start.
3. Inspect the interior of the machine for loose
screws or wires. Check that no refrigerant
lines are rubbing each other. Check that the
fan blade turns freely (air cooled).
4. Check that the unit is installed correctly
according to the final check list (page 8).
For example, with an air cooled, single phase
unit in temperatures of 65
water, you should observe values close to
these:
0
F. air and 500 F.
••Low side pressure: 27 psig.
••High side pressure: 210 psig.
••Gearmotor amps: 1.2
••Compressor amps: 7.1
The water cooled discharge pressure should
be constant at about 220 psig.
The above numbers are for new, clean
machines, you can expect to see some values
higher, and some lower between different
units.
4. On air cooled models, the condenser will
begin to discharge warm air, on water cooled
models, the water regulating valve will open,
and warm water will be discharged into the
drain.
5. The unit should soon be making ice, if
desired, the low side pressure can be
checked: it should be 30 psig + or - 4 psig.
The suction line temperature at the
compressor is normally very cold, nearly to the
point of frost up to the compressor body, but
not on it.
The air cooled discharge pressure will depend
upon air and water temperatures, but should
be between 200 psig and 280 psig.
February, 1989
6. THERE ARE NO ADJUSTMENTS TO
MAKE, so replace the panels.
7. Clean and/or sanitize the storage bin
interior, wipe off the exterior with a clean,
damp cloth.
8. Give the owner/user the service manual,
instruct him/her in the operation of the unit,
and make sure they know who to call for
service.
9. Fill out the manufacturers registration card,
and mail it to the Scotsman Factory.
10. Fill out the field quality audit form, and mail
it to the Scotsman factory.
Page 9
RESET SWITCH
CLEANING DRAIN
TUBE
GEARMOTOR/EVAPORATOR
MOUNTING PLATE:
SLIDES OUT FOR SERVICE
GEARMOTOR
NM1250
COMPONENT DESCRIPTION
Control Box: Contains the electrical controls
that operate the machine.
Low Pressure Cut Out: A manual reset
switch set to shut the machine off should the
low side pressure go below 0-4 psig.
High Pressure Cut Out: A manual reset
switch sensing the high side refrigeration
pressure. It is set to shut the machine off at
450 psig.
Reset Switch: Manual reset. Glows when the
unit shuts off from ice discharge chute being
overfilled (opening the microswitch at the top
of the chute), or if either of the pressure cut
out switches opens.
Evaporator: A vertical stainless steel tube,
refrigerated, and water filled. In it, there is a
stainless steel auger.
Reservoir: Float operated, it maintains the
water level in the evaporator at a constant
level, it also contains the water level sensor.
CONTROL BOX
Water Level Sensor: Senses if there is water
in the reservoir to make ice out of. Will shut
the machine off it there is none.
Ice Discharge Chute: Directs the ice made by
the evaporator into the storage bin.
Ice Level Sensor: An electronic "eye", it
senses the presence of ice in the bottom of
the ice discharge chute. Operates to turn the
ice machine on and off automatically as the
level of ice in the bin changes.
Gear Motor: An oil filled, speed reduction
gearbox, driving the auger.
Cleaning Drain Tube: When uncapped and
lowered, drains the evaporator.
Compressor: The refrigerant vapor pump.
Condenser: Air or water cooled, where the
heat removed in ice making is discharged.
Expansion valve: The refrigerant metering
device.
LOW PRESSURE
CUT OUT
RESERVOIR
WATER LEVEL SENSOR
(INSIDE RESERVOIR)
STRAINER
COMPRESSOR
HIGH PRESSURE
CUT OUT
CONDENSER
ICE CHUTE
EXPANSION
VALVE
EVAPORATOR
ICE LEVEL
SENSOR
February, 1989
Page 10
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