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

COMPONENT DESCRIPTION: Control Box

CONTACTOR

NM1250

Contactor: A definite purpose contactor

connecting the compressor to the power
supply.

Circuit Board: Controlling the ice machine
through sensors and relays. The sensors are:
ice level, and water level. The relays are for
the gear motor (with a built in time delay to
clear the evaporator of ice when the unit turns
off) and for the compressor.

Transformer: Supplies low voltage to the
circuit board.

Low Pressure Control (Cut Out): A manual
reset control to shut off the ice machine when
the low side pressure drops below a preset
point, 0-4 psig.

Potential Relay: The compressor start relay.
On/Off Switch: Manual control for the

machine.
Reset Switch: Manual reset. Glows when

the unit shuts off from the ice discharge chute
being overfilled (pressure of the ice opening
the microswitch at the top of the chute), or if
either of the pressure cut out switches opens.

LOW PRESSURE

CUT OUT

ON/OFF SWITCH

TRANSFORMER

CIRCUIT BOARD

POTENTIAL RELAY

RESET SWITCH

February, 1989

Page 11

BEARING

EVAPORATOR

NM1250

COMPONENT DESCRIPTION

Evaporator: A refrigerated vertical tube filled
water and containing a water seal and auger.

Auger: A solid stainless steel double spiral
auger, it pushes the ice crystals up to the top
of the evaporator.

Water Seal: A two part "face" seal, the top
half rotating with the auger, the bottom half
stationary, the sealing action being where the
two seal "faces" meet.

Ice Sweep: A plastic cap with "fingers". It
revolves with the auger to "sweep" the ice into
the ice chute.

BREAKER

Breaker: Where the ice is compressed and

much of the extra water is squeezed out of it
before it is discharged into the bin.

Motor: A permanent split capacitor motor that
drives the gear reducer.

Bearing: As the ice is pushed up the
evaporator, the auger is thrust down, and
pressure from the auger thrust is taken up by
this bearing.

ICE

SWEEP

AUGER

ICE CHUTE

WATER SEAL

ICE LEVEL

SENSORS

DRIVE MOTOR

February, 1989

Page 12

ELECTRICAL SEQUENCE

NM1250

Refer the wiring diagram as needed.

If the machine is switched off at the master
switch, but is otherwise ready to go, switching
the master switch to on and pressing the start
reset switch does the following:

••

The bin empty light on the circuit board
goes on

••There is a 15 second delay

••If there is enough water in the reservoir, the

circuit board will allow the machine to start
up.

Start up consists of:

••The compressor relay and auger motor

relay become energized, connecting power
to the windings of the auger motor.

••The auger motor starts, and the centrifugal

switch closes, connecting power to the
compressor contactor coil.

••The contactor is energized, connecting

power to the compressor, and the
compressor starts.

••As ice goes past the ice level sensors, the

bin empty light will stay on, and the
machine will continue to run, unless the ice
stays between the sensors for more than
15 seconds (bin full). At that point, the bin
empty light goes out, and the machine
shuts down.

Shut Down consists of:

••

The compressor relay opens.

••The compressor contactor opens

••The compressor stops

••The auger motor is run by the circuit board

for 2.5 more minutes, clearing out ice in the
evaporator, and then

••The auger motor relay opens, and the

auger motor stops.
If the ice level sensor is clear (bin empty) for
more than 15 seconds, the machine will start
up again.

Another purpose of the circuit board is to turn
the machine off if there is not enough water in
the machine.

••When the water level in the reservoir falls

below the water level sensor, the machine

will "shut down"

••When the water refills the reservoir, the

machine will start up again.
Separate from the circuit board:

••If the high pressure control (cut out) opens,

the machine will stop immediately (through

the relays on the circuit board) and cause

the reset switch on the circuit board to light

up. It must be manually reset at the control

and at the reset switch on the circuit board.

••If the low pressure control (cut out) opens,

the machine will stop immediately (through

the relays on the circuit board) and cause

the reset switch on the circuit board to light

up. It must be manually reset at the control

and at the reset switch on the circuit board.

••If the spout switch opens, the machine will

stop immediately (through the relays on the

circuit board) and cause the reset switch on

the circuit board to light up. It must be

manually reset at the reset switch on the

circuit board.

••The master switch is the manual control for

the complete machine, but it is not a

service disconnect.

February, 1989

Page 13

NM1250

OPERATION

Water

Water enters the machine through the 3/8"
male flare at the rear of the cabinet, goes to
the water reservoir which it enters through the
float valve. The water then goes out the
bottom of the reservoir tank to the bottom of
the evaporator.

Reservoir overflow or evaporator
condensation is routed to the drain.

Water cooled models have a separate water
circuit for the cooling water: it enters the fitting
at the rear, goes to the water regulating valve,
then to the water cooled condenser and then
down the drain.

ADJUSTMENT OF WATER LEVEL

EVAPORATOR

DRAIN

RESERVOIR

STRAINER

WATER LEVEL

EVAPORATOR

ICE

CHUTE

DRAIN

WATER SCHEMATIC

February, 1989

Page 14

OPERATION: Refrigeration

NM1250

Beginning at the compressor, the refrigerant
502 is compressed into a high temperature
gas. The discharge line directs this gas to the
condenser. At the condenser (air or water
cooled) the gas is cooled by either air or water
and it then condenses into a liquid. This high
pressure liquid then goes through the liquid
line to the expansion valve. The thermostatic
expansion valve meters liquid refrigerant into
the evaporator, the volume of liquid refrigerant
depending upon the temperature of the
evaporator; warmer evaporators get more
refrigerant and colder evaporators get less.

REFRIGERATION SYSTEM SCHEMATIC

AIR COOLED
CONDENSER

At the evaporator, the refrigerant enters an
area of relatively low pressure, where it can
easily "boil off" or evaporate. As it
evaporates, it absorbs heat from the
evaporator and whatever is in contact with it
(such as the water inside it). After the
evaporator, the refrigerant, now a low
pressure vapor, goes through the suction line
back to compressor, where the cycle is
repeated.

SUCTION LINE

FAN MOTOR

DISCHARGE

LIQUID LINE

LINE

THERMOSTATIC

EXPANSION

VALVE

EVAPORATOR

COMPRESSOR

February, 1989

Page 15

NM1250

MAINTENANCE AND CLEANING

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
A Scotsman Ice System represents a sizable investment of time and money in any company’s

business. In order to receive the best return for that investment, it MUST receive periodic
maintenance.

It is the USER’S RESPONSIBILITY to see that the unit is properly maintained. It is always
preferable, and less costly in the long run, to avoid possible down time by keeping it clean;
adjusting it as needed; and by replacing worn parts before they can cause failure. The following
is a list of recommended maintenance that will help keep the machine running with a minimum of
problems.

Maintenance and Cleaning should be scheduled at a minimum of twice per year.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

//////////////////////////WARNING/////////////////////////////

Electrical power will be ON when doing in
place cleaning. Switch it OFF before
completing the cleaning procedures.

/////////////////////////////////////////////////////////////////////////
ICEMAKING SYSTEM: In place cleaning

1. Check and clean any water treatment
devices, if any are installed.

2. Pull out and remove the front panel.

3. Move the ON-OFF switch to OFF.

4. Remove all the ice from the storage bin.

5. Remove the cover to the water reservoir
and block the float up.

6. Drain the water reservoir and freezer
assembly using the drain tube attached to the
freezer water inlet. Return the drain tube to its
normal upright position and replace the end
cap.

//////////////////////////WARNING///////////////////////////////
Scotsman Ice Machine Cleaner contains

Phosphoric and Hydroxyacetic acids.
These compounds are corrosive and may
cause burns. If swallowed, DO NOT induce
vomiting. Give large amounts of water or
milk. Call Physician immediately. In case
of external contact, flush with water. KEEP
OUT OF THE REACH OF CHILDREN.

//////////////////////////////////////////////////////////////////////////

7. Prepare the cleaning solution: Mix eight
ounces of Scotsman Ice Machine Cleaner with
three quarts of hot water. The water should be
between 90-115 degrees F.

8. Slowly pour the cleaning solution into the
water reservoir until it is full. Wait 15 minutes,
then switch the master switch to ON.

9. As the ice maker begins to use water from
the reservoir, continue to add more cleaning
solution to maintain a full reservoir.

10. After all of the cleaning solution has been
added to the reservoir, and the reservoir is
nearly empty, switch the master switch to OFF.

11. After draining the reservoir, as in step 6,
wash and rinse the water reservoir.

12. Remove the block from the float in the
water reservoir.

13. Switch the master switch to ON

14. Continue ice making for at least 15
minutes, to flush out any cleaning solution.
Check ice for acid taste - continue icemaking
until ice tastes sweet.

///////////////////////////////WARNING///////////////////////////

DO NOT USE any ice produced from the
cleaning solution.

Be sure no ice remains in the bin.
///////////////////////////////////////////////////////////////////////////

15. Remove all ice from the storage bin.

16. Add warm water to the ice storage bin and
thoroughly wash and rinse all surfaces within
the bin.

17. Sanitize the bin interior with an approved
sanitizer using the directions for that sanitizer.

18. Replace the front panel.

February, 1989

Page 16

SLIDE IN

AND OUT

MAINTENANCE

////////////////////////////WARNING////////////////////////////

Disconnect electrical power before
beginning.

/////////////////////////////////////////////////////////////////////////

1. The bin control uses devices that sense
light, therefore they must be kept clean
enough so that they can "see". At least twice a
year, remove the bin control sensors from the
base of the ice chute, and wipe the inside
clean, as illustrated.

WATER

RESERVOIR

NM1250

ICE CHUTE

ICE LEVEL

SENSORS

WATER LEVEL

SENSOR

2. The ice machine senses water level by a
probe located in the water reservoir. At least
twice a year, the probe should be removed
from the reservoir, and the tip wiped clean of
mineral buildup.

3. The bearing in the breaker should also be
checked at least two times per year.

Check the bearing by:

••removing the ice chute cover

••unscrewing the ice sweep

••removing the water shed

••using a spanner wrench and unscrewing

the breaker cover

••unscrewing the auger stud

Inspect the assembly, looking for wear.
See Removal and Replacement to replace

bearing or seals. Reverse to reassemble.

4. Clean or replace the air cooled condenser
filter.Clean the air cooled condenser. Use a
vacuum cleaner or coil cleaner if needed.

Do NOT use a wire brush.

5. Check and tighten all bolts and screws.

ICE

SWEEP

SPANNER

WRENCH

BREAKER

COVER

BREAKER

February, 1989

Page 17

ALLEN HEAD

SCREWS

BREAKER &

BEARING &

AUGER

ASSEMBLY

NM1250

MAINTENANCE: Auger

///////////////////////////WARNING////////////////////////////

Disconnect electrical power before
begining.

Handle auger with care, it has sharp edges.
/////////////////////////////////////////////////////////////////////////

In some installations the water supply to the
icemaker will be so concentrated with
dissolved minerals, (such as calcium
carbonate) that as ice is made, the
evaporator and auger become coated with the
minerals, requiring a more frequent cleaning
than twice per year. If in doubt about the
condition of the evaporator and auger, the
auger can be removed so the parts can be
inspected.

Note: Water filters can filter out suspended
solids, but not dissolved solids. "Soft" water
may not be the complete answer. Check with
a water treatment specialist regarding water
treatment.

For more information on removal of these
parts, see REMOVAL AND REPLACEMENT.

1. To remove the auger, remove front and top
panel. If top panel cannot be removed, or if
there is less than 6" clearance over the top of
the machine, the gearmotor/evaporator may
be slid out for service access. See Removal
And Replacement.

2. Remove 3 hex studs holding ice chute
cover to ice chute, and remove cover.

3. Unscrew and remove ice sweep.

4. Loosen band clamp under ice chute, and
remove ice chute from evaporator.

5. Remove 4 allen head screws holding
breaker to evaporator.

6. Pull up on breaker to remove auger.
Allow the auger to dry, the stainless steel of

the auger and evaporator must be clean and
bright. Clean the auger and evaporator as
required. DO NOT HONE THE
EVAPORATOR.

7. Replace the water seal.

8. Reverse to reassemble.

February, 1989

Page 18

SERVICE DIAGNOSIS: Condition - No Ice Being Produced

NM1250

STATUS:

A. Check: Voltage to the unit, restore it if there is none. Compare to the nameplate.
B. Check: The master switch, switch ON if off.
C. Check: The 3 reset switches, (circuit board, high and low pressure): depress and release

each switch. If the still does not start, check: the spout switch; the high and the low side
pressures.

D. Check the low pressure cut out, if closed go to E, if it is open, it could be due to:

••

Low refrigerant charge

NOTHING OPERATES

••The auger not turning

••

Restricted system

••TXV not opening

1. Check the low side pressure, the low pressure cut out opens at pressure below 4 psig.
If open, reset and:

a. Check if the auger is turning, if it is not, remove the gearbox and:

Check for internal damage, repair and replace in the machine.
b. Check for low charge, add some refrigerant, if the unit will operate,(normal
low side pressure being about 30 psig) stop and look for a leak, repair, replace the

drier, evacuate, and weigh in the nameplate charge. If, with added charge, the unit

does not operate:

Check for a restricted system, replace the drier, evacuate, and weigh in a

nameplate charge.

Check for a Thermostatic Expansion Valve that does not open, if defective,

replace it. Replace the drier, evacuate, and weigh in the nameplate charge.

E. Check the high pressure cut out, if closed go to F, if open check:

1.The pressure control opens at 450 psig. Check the high side pressure, reset the control,
and observe: on water cooled, that water soon begins to flow from the condenser drain;
or, on air cooled, that the fan is forcing air through the condenser. If the unit trips out on
pressures below 450 psig, replace the control. If the pressures rise above the trip out
point, and the unit shuts down:

a. Check for adequate water flow on water cooled, if adequate, clean the interior
of the condenser. If the pressures are still too high replace the water regulating valve.
b. Check for adequate air flow on air cooled. Clean the condenser and (if used) the

filter. If the air flow is poor because of the installation, advise the user that the unit
should be moved, or the air around it kept cooler.

Check the fan motor for tight bearings and proper rotation.

Check that the fan blades are clean, and the fan secure to the fan motor shaft.

F. Check the spout switch. It opens from excess pressure of ice inside the ice chute: this should
only happen when the machine does not shut off when the ice storage bin is full. This switch will
reset when the ice melts, but the machine will not resart until the reset switch on the circuit board
is pressed.

G. Check the water level in the reservoir. The machine will not run if there is not enough water in
the reservoir.

1. Restore/adjust water level. See the next step.

February, 1989

Page 19

NM1250

SERVICE DIAGNOSIS: Condition - No Ice Being Produced

STATUS:

H. Check: The gear motor, if it will not run, the compressor will not run. If no power to it:

Check: The indicator lights on the circuit board, the bin empty light should be ON, the no water
light should be OFF .

1. If the bin empty and no water lights are off, check the transformer.

side should have between 208-230 volts. If the line side has the correct voltage and the

2. If the transformer is good, and the bin empty light is OFF, check the ice level sensors.

Testor Model NM1 into the circiut board.

3. If the transformer is fine, and the "no water" light is ON, check the water level sensor.

MORE INFORMATION ON THE TESTOR MAY BE FOUND ON THE LAST PAGES OF THE
MANUAL.

NOTHING OPERATES

a. Transformer "load" side should have 12 to 15 volts. If not, check the "line" side. The line

load side does not, replace the transformer.

a. Remove sensors by sliding them sideways out of the ice chute. Visually inspect them,
clean if needed.
b. Look through the ice chute "eye" hole for something blocking the ice chute.
c. If the unit still does not run, replace the ice level sensors.
d. If the bin empty light is still OFF, check the circuit board.

1. Unplug "opto trans" and "LED" connectors from the circuit board.

2. Plug "opto trans" and "LED" connectors from the Scotsman Electronic Control

a.Move the "bin full" switch on the tester to the full position. The bin full light
on the tester should be ON, if not, replace the circuit board.
If the bin full light on the tester is ON, move the tester switch to "bin empty"
the light on the tester should go OFF and the bin empty light on the circuit
board should go ON. If not, replace the circuit board. If it does as above,
and the machine still does not run, replace the ice level sensors.

a. Check the water level in the reservoir, restore if low. If the water level is ok:
b. Remove the water level sensor from the reservoir and clean the tip if dirty.
CAUTION: THE TIP IS MADE OF GLASS
c. Replace the water level sensor. If the no water light is still on, check that the
"water sen" plug is firmly plugged into the circuit board.
d. If the no water light is still on,

1. Unplug the "water sen" connector from the circuit board.

2. Plug "water sen" connector from the Scotsman Electronic Control tester into

the circuit board.

a. Move the water switch on the tester to "no water" and the no water light
on the circuit board should go on. If not, replace the board.
b. Move the water switch to the "water" position, the no water light should
go off, if not, replace the circuit board.
c. If after the above, the machine still will not run, replace the water level
sensor

February, 1989

Page 20

SERVICE DIAGNOSIS: Condition - No Ice Being Produced

NM1250

STATUS:

A. Check the compressor relay.

The relay is on the circuit board, if it does not supply power to the contactor coil, the
compressor will not run.

1. Check for power at the contactor coil, if none:

2. Check the contactor coil. If the coil is open, replace the contactor.

3. Check the auger drive motor centrifugal switch. If, when the drive motor is running,
contact 4 (black wire removed) has no power, and all of the above switches have been
checked, replace the centrifugal switch, or the drive motor.

4. If the compressor relay on the circuit board has power on the NO contact, but not on the COM
contact, replace the circuit board.

B. Check the compressor

1. Check the compressor start relay.

2. Check the start capacitor.

3. Check the windings of the compressor for open windings or shorts to ground.
Replace those items found defective.

GEARMOTOR OPERATES, COMPRESSOR DOES NOT

a. Check for power at the compressor relay at the circuit board.
If there is power at the relay, but none at the contactor coil,

Check for an open wire between the relay and the contactor.

February, 1989

Page 21

NM1250

SERVICE DIAGNOSIS: Condition - Low Ice Production

STATUS:

A. Check the air cooled condenser for dirt. Clean as required. Check the head pressure on water

cooled. Adjust as required. If the head pressure is very high:

1. Air cooled. Check for high air temperatures, or restrictive air flow. Correct as needed.

2. Water cooled. Check for high water temperatures, or low water pressure. Correct as needed.

3. The refrigerant may contain non condensable gases, purge, evacuate, and recharge per
nameplate.

B. Check the evaporator

1. Clean the evaporator, the mineral build up will adversely affect the ice machines production.

2. Check the evaporator for water leaks, replace the water seal if found to be leaking.

3. Check the low side pressure; normal is about 30 psig. If low, assume a refrigerant leak,
locate, repair and recharge.

4. Check the insulation on the evaporator. It should be dry, with no wet spots or frost. If the
insulation has failed: repalace the evaporator or add extra insulation in the from of foam tape to
the evaporator.

EVERYTHING IS OPERATING

If no leak, the TXV may be restricted, defective or not adjusted properly. If needed,
replace the TXV, evacuate, and recharge per nameplate.

C. Check the compressor.

1. The compressor may be inefficient.
a. Check the amp draw, if low change the compressor.
b. if the amp draw is normal, pinch off the suction line to check the pull down capability
of the compressor. The compressor should pull down to 25 inches of vacuum and
hold there for three to five minutes

.

February, 1989

Page 22

NM1250

REMOVAL AND REPLACEMENT: Water Reservoir & Bin Control

WATER RESERVOIR

1. Shut off the water supply to the icemaker.

2. Remove front panel and reservoir cover.

3. To remove float only, pry the mounting

flanges apart enough to lift one float pivot pin
out of the flange hole, and pull float up and out
of the reservoir.

4. To remove reservoir, disconnect water inlet

compression fitting at reservoir inlet.

5. Remove drain hose from reservoir.

6. Remove evaporator inlet hose from

reservoir.

7. Remove mounting screws from reservoir

bracket, and remove reservoir from icemaker.

8. Reverse to reassemble.

FLOAT MOUNTING

FLANGES

SLIDE

BINCONTROLS

IN AND OUT

ICE

CHUTE

BIN CONTROLS (Ice Level Sensors)

1. Disconnect electrical power.

2. Remove front panel.

3. Remove control box cover.

4. Locate ice chute, at the base of the chute,
in front of and behind it are two plastic bin
control mounts.

5. Slide each bin control to the left, and in the
control box, disconnect the electrical leads
connecting the bin control to the circuit board.

6. Reverse to reassemble, be certain that the
bin controls are aligned so that the ice level
sensors are visible (centered) through the
holes in the cube chute.

February, 1989

Page 23

SEALS

NM1250

REMOVAL AND REPLACEMENT: Bearing And Breaker

Note: Removal of the auger, water seal,
evaporator and gearmotor must begin at the
top of the assembly.

To Remove the Breaker Bearing Assembly:
//////////////////////////////WARNING////////////////////////////
Disconnect the electrical power to the

machine at the building source BEFORE
proceeding with any repair.

//////////////////////////////////////////////////////////////////////////

1. Remove panels and disconnect electrical

power.

2. Unscrew three studs and remove ice chute

cover.

3. Unscrew and remove ice sweep.

4. Remove insulation halves from outside of

ice chute, loosen band clamp under ice chute,
lift up and remove ice chute.

5. The breaker may be removed from the

auger and evaporator without disturbing the
auger.

a. Use spanner wrench and unscrew breaker
cover from breaker (left hand threads)

b. Unscrew auger stud from top of auger.
c. Unscrew 4 allen head cap screws holding

breaker to evaporator.

d. Lift up, and remove breaker/bearing
assembly from auger & evaporator.

6. Service the bearing. Check for rust, rough
spots and damage.

a. The bearing is pressed into the breaker, to
remove the bearing and replace it an arbor
press is needed.

b. Replace lower seals before installing new
bearing in breaker.

Note: seals must be pressed in with a tool
pushing against the outer edge only, they will
not install by hand.

Replace parts as required. Re-grease bearing
with Scotsman part no. 19-0609-01 bearing
grease. Replace top seal, and check the
o-rings, replace if cut or torn.

7. Reverse to reassemble: specific tools and
materials are required to install properly.

a. Add food grade grease such as Scotsman
part number 19-0569-01 to the seal area
before installing on the auger.

b. Check the seal to shaft areas for cuts, or
rough spots: none are permitted.

Step 5-a Step 5-b Step 5-c

ICE

SWEEP

SPANNER

WRENCH

BREAKER

COVER

AUGER

STUD

February, 1989

Page 24

BEARING

REMOVAL AND REPLACEMENT: Auger

NM1250

To Remove the Auger:

Turn off the water to the machine, and unclip
the evaporator drain hose, pull it down and
drain the evaporator into the bin or a container.

1. The top panel must be removed.

2. Remove ice chute cover.

3. Unscrew ice sweep.

4. Loosen band clamp and remove ice chute

body.

5. The auger and breaker/bearing may now be

removed as an assembly.
a. Unscrew 4 allen head cap screws holding

breaker to evaporator.
b. Lift up on breaker and remove auger from

evaporator.

Note: If the auger is stuck, the breaker must

be removed

BREAKER

AND

AUGER

ASSEMBLY

from the
auger.

The breaker
may be
removed from
the auger and
evaporator
without
disturbing the
auger.

a. Use
spanner
wrench and
unscrew
breaker cover
from breaker

(left hand threads)
b. Unscrew auger stud from top of auger.
c. Unscrew 4 allen head cap screws holding

breaker to evaporator.
d. Lift up and remove breaker from

evaporator.
e. If the auger is stuck use a slide hammer

type puller to pull on the auger at the threaded
hole. The size of that hole is 5/8"-18.

Inspect the auger, the critical areas of the
auger are:

1. The auger body. It should be clean and
shining. Sometimes an auger will appear
clean when wet, but after it is dry it will be
seen to be stained. Scrub the auger with ice
machine cleaner and hot water.

///////////////////////////WARNING//////////////////////////////
Ice machine cleaner is an acid. Handle it with

extreme care, keep out of the reach of
children.

//////////////////////////////////////////////////////////////////////////

2. The water seal area. Because the auger
has been removed, the water seal will have to
be replaced. Remove the water seal top half
from the auger, and inspect the auger for
minerals clean as required.

SLIDE

HAMMER

PULLER

THREAD

INTO

AUGER

/////////////////////////

AUGER HAS

SHARP EDGES

/////////////////////////

GEARMOTOR

MOUNTING PLATE

SLID OUT

February, 1989

Page 25

NM1250

REMOVAL AND REPLACEMENT: Water Seal

REMOVAL OF THE WATER SEAL

RETAINING

WATER

SEAL

RING

/////////////////////////////WARNING////////////////////////////
Disconnect the electrical power to the

machine at the building source BEFORE
proceeding with any repair.

//////////////////////////////////////////////////////////////////////////
To Remove the Water Seal:

(Assuming all steps to remove the auger have
been performed.)

1. The gearmotor/evaporator assembly will
have to be exposed.

2. Remove the 4 hex head cap screws holding
the evaporator to the gearmotor assembly.
Lift the evaporator up and off of the gearmotor.

3. Remove the snap ring or wire retainer from
the grove under the water seal.

4. Pull or drive out the lower half of the water
seal.

To Replace the Water Seal:

1. Lubricate the water seal with water, and
push the water seal into the bottom of the
evaporator slightly past the grove for the snap
ring.

2. Replace the snap ring and pull the water
seal down against it.

3. The part of the water seal that rotates with
the auger must also be replaced. Remove the
old part from the auger and clean the
mounting area.

4. Place a small bead of food grade silastic
sealant (such as 732 RTV or Scotsman part
number 19-0529-01) on the area of the auger
where the water seal is to be mounted.

5. Carefully push the water seal (rubber side
against the auger shoulder and the silastic.)

/////////////////////////////CAUTION///////////////////////////
Do not get any silastic onto the face of the

seal.
/////////////////////////////////////////////////////////////////////////

6. Allow the auger and seal to air dry until the
silastic is dry on the surface.

7. If the original water seal was leaking, it
would be a good idea to inspect the interior of
the gearmotor.

February, 1989

Page 26

REMOVAL AND REPLACEMENT: Evaporator

To Replace the Evaporator:

REPLACING THE WATER SEAL

PLACE A BEAD OF

FOOD GRADE

SEALANT HERE

ROTATING HALF OF

WATER SEAL

(Assuming all the steps for removal of the
thrust bearing, breaker, auger, and water seal
have been performed.)

1. Discharge the refrigerant from the ice
maker.

2. Unsweat the refrigerant connections:
a) At the thermostatic expansion valve outlet.
//////////////////////////////CAUTION///////////////////////////

Heat sink the TXV body when unsweating
or resweating the adjacent tubing.

//////////////////////////////////////////////////////////////////////////

b) At the suction line at the joint about 3" from
the evaporator.

3. Remove the evaporator.

4. Unsweat the drier from the liquid line.

5. After installing a new water seal in the new
evaporator (see "To Replace the Water Seal")
sweat in the new evaporator at the old
connections.

6. Install an new drier in the liquid line.

7. Evacuate the system until dehydrated, then
weigh in the nameplate charge. Check for
leaks.

8. Install auger, breaker, breaker bearing
assembly, and ice discharge chute in reverse
order of disassembly. See "To Reassemble
Evaporator and Auger"

To Reassemble the Evaporator and Auger

1. After the gearmotor has been inspected,
fasten the evaporator to the gear motor, be
sure that the number of shims indicated on the
gear case cover is in place between the
gearcase cover and the drip pan gasket.
Torque the bolts to 110 inch pounds.

2. Lower the auger into the evaporator barrel,
slightly turning it to match up with the drive
end. Do Not Drop Into the Evaporator.

3. Complete the reassembly by reversing the
disassembly for the breaker & thrust bearing
assembly.

NM1250

February, 1989

Page 27

NM1250

REMOVAL AND REPLACEMENT: Gearmotor

To Remove and Repair the Gearmotor
Assembly:

(Assuming that the procedures through
removal of the water seal have been
performed.)

1. Remove the electrical wires from the gear

drive motor.

2. Unscrew the 4 cap screws holding the

gearmotor to the gearmotor plate.

3. Remove the gearmotor from the icemaker.

To Inspect the gearmotor.

A) Remove the cap screws holding the
gearmotor case halves together and pry the
two cases apart.

B) To lift off the cover, lift up until you can feel
internal contact, then pull the cover towards
the output gear end, and then lift the cover
(with drive motor attached) up and away from
the gear motor case.

Note: The case cover output gear, bearings,
and shaft are one pressed together assembly.
Replace as a unit.

C) Inspect the oil, gears, and bearings. If the
oil level and condition is acceptable, quickly
check the gears and bearings. They are likely
to be fine if the oil is.

If there is evidence of water in the oil (rusty
bearings and gears; the oil having a creamy
white appearance; oil level too high) carefully
inspect the bearings and gears. If in doubt
about the condition of a part, replace it. The oil
quantity is 14 fluid ounces, do not overfill.

Note: The gears and bearings are available
only as pressed together sets.

D) After replacing parts as required, (if any)
reassemble the gearcase. The two smaller
gears and the oil should be in the lower case,
the output gear will be with the cover. As you
lower the cover onto the lower case, cover will
have to be moved closer to the second gear
after the output gear has cleared the second
gear top bearing.

E) After the case is together, and the locating
pins are secure in both ends, replace all cap
screws.

Note: If the gearcase cover was replaced, the
replacement part MAY HAVE BEEN shipped
with a certain number of shims. The number of
shims used must match the number on the
gearcase cover. If there were no shims on
the new parts, do not use any shims. Do
not use the old shims.

4. Bench test the gearmotor, check for oil
leaks, noise, and amp draw.

February, 1989

Page 28

REMOVAL AND REPLACEMENT: Gearmotor

BEARING

SEAL

WATER SHED

SEAL

GEARCASE

COVER,

BEARINGS,

OUTPUT GEAR,

OUTPUT SHAFT

NM1250

CENTRIFUGAL

SWITCH

DRIVE MOTOR

2ND GEAR AND

BEARINGS

1ST GEAR AND

BEARINGS

GASKET

GEARCASE

February, 1989

Page 29

NM1250

CIRCUIT BOARD TESTING

///////////////////////////////////////////////////////////////////////WARNING//////////////////////////////////////////////////////////////////

These procedures require the machine to be connected to the power supply. The voltages of the
electronic circuit are very low, but HIGHER VOLTAGES ARE PRESENT IN THE UNIT. Do not
touch anything but the tester while the unit is being checked out. Make all connections to the
circuit board with the ELECTRICAL POWER OFF.

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
INSTRUCTIONS FOR USING TESTER, model FC1 (Optional, order part no. A33942-001)

(These instructions assume that the unit will not run, and prior investigation of electric power,
controls, and mechanical parts indicates that the electronic circuit may be at fault.)

If the "Reset" indicator (located in the "reset" switch) is off and the "NO WATER" indicator is lit,
but inspection shows that the water level in the reservoir is above the top of the water level
sensor, OR the "BIN EMPTY" indicator is off while inspection shows that the ice level sensors are
properly aligned, clean and not obstructed, use the tester as follows:

Bin Control

electrical power on, the master switch on, and
all reset switches “reset”.

1. Unplug “photo trans” and “LED” connectors

from the circuit board.

2. Plug “photo trans” and “LED” connectors

from the tester into the circuit board.

a. Move the “bin full” switch on the tester to

Full. The light on the tester should be ON.
If the light on the tester is not on, the circuit

board should be replaced.

Note: All testing is done with the

b. If the light on the tester IS on, move the
“bin full” switch to Bin Empty. The light on the
tester should go OFF, and the Bin Empty light
on the circuit board should go ON.

If the Bin Empty light is ON, wait 10-20
seconds for the machine to start, if the
machine starts, replace the ice level sensors.
If the Bin Empty light does not come ON, the
circuit board should be replaced.

SWITCH TO

"FULL"

PHOTO

TRANS

LED

LIGHT GOES

LIGHT GOES

ON

ON

LIGHT
GOES

OFF

SWITCH TO

"BIN EMPTY"

February, 1989

Page 30

CIRCUIT BOARD TESTING

NM1250

Water Level

1. Unplug “water sen” connector from control
board.

2. Plug “water sen” connector from Scotsman
tester into circuit board.

a. Move “water” switch on tester to No Water
position. The No Water light on the circuit
board should go ON. If not, replace the circuit
board.

LIGHT ON

WATER SENS

b. Move the “water” switch on the tester to the
Water position. The No Water light on the
board should go OFF. If not replace the circuit
board. If the light does go off, replace the
water level sensor.

LIGHT OFF

SWITCH TO

NO WATER

SWITCH TO

WATER

If the Bin Empty light is ON, wait 10-20
seconds for the machine to start. The machine
should start.

February, 1989

Page 31