Scotsman NM952R Operator’s Manual

INTRODUCTION

NM952R

To the owner or user: The service manual you are
reading is intended to provide you, and the
maintenance or service technician, with the
information needed to install, start up, clean,
maintain, and service this ice system.

The NM952R is a remote condenser modular ice
system that fits a variety of Scotsman storage bins.
It features: front service for the freezer, gearmotor,
control box, water reservoir, and bin control; an
electronic circuit for monitoring ice and water level;
a thermostatic expansion valve; and R-22 as the
refrigerant.

TABLE OF CONTENTS

For the Installer

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Remote Condenser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

For the Plumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

For the Electrician . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Final Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Component Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Maintenance & Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Removal and Replacement

Water Reservoir & Bin Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Thrust Bearing & Breaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Auger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Water Seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Evaporator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Gearmotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Circuit Board Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Parts Lists and Wiring Diagrams are located in the center of this manual, printed on yellow
paper.

November 1992

Page 1

This manual was printed on

recycled paper.

Electrical

Inlet

NM952R

FOR THE INSTALLER

The NM952R is designed to fit the following
Scotsman storage bins:

••B90 and extensions, with bin top KBT18.

••BH800 using bin top KBT15 (one unit).

••

BH800 if using two units, no bin top needed.

••BH900 using bin top KBT24 (one unit)

••BH900 with bin top KBT25 (two units side by

side

••BH550 or HTB500 using bin top KBT14.

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

••All kits, legs, and information required for the

specific job.

Back View

Allow 6" above

machine for service.

Liquid Line
Connection

Discharge Line

Connection

Remote Condenser

Junction Box

SPECIFICATIONS: ICE MAKER

Model Number

NM952RE-32A

NM952RE-3A

Dimensions

(w/o bin)

H X W X D

27" x 21" x 24"

same

20.84"

Basic

Electrical

208-230/60/1
208-230/60/3

Drain

3/4" FPT

Ice Type

Nugget

same

Cond.

Type

R/Air
R/Air

Water Inlet

3/8" Flare

3"

2.96"

Refrigerant Charge*

256 ounces of R-22
* Always go by the nameplate
charge.

5.25"

The Standard Finish is Enamel - Sandalwood. There is an optional stainless steel panel kit, SPKFM21
available to convert the unit to Stainless Steel. It is field installed.

November 1992

Page 2

REMOTE CONDENSER SPECIFICATIONS

27.81"

19.86"

+Included with the ice makers minimum circuit ampacity.

Use this value to determine wire size between ice maker and

fan motor.

1/2" MALE QUICK CONNECT

COUPLING FOR USE WITH

RT2225 OR RT2240

PRECHARGED LINE SET

22"

5.75"

5.38"

NM952R

32.56"

6.5"

3.5"

1.94"

5.0"

MODEL USE WITH MINIMUM CIRC.

RC1022-32
RC1222-32

DIMENSIONS
H" X W" X D"

27.8" X 22 X 37.94"
SAME

1 or 2 NM952R’S

LIQUID LINE 3/8" MALE

QUICK CONNECT

COUPLING FOR USE WITH

RT2225 OR RT2240

PRECHARGED LINE SET

1 NM952R

7.5"

AMPACITY+

2
2

BASIC

ELECTRICAL

208-230/60/1

SAME

RT-2225 Precharged line set, 25’, R-22
RT-2240. Precharged line set, 40’, R-22
KCMR230. Fan Relay Kit used when two 230 volt (-32) ice makers are on one 230 volt (-32) two circuit

condenser.

November 1992

ICE MAKER NAMEPLATE

LOCATED ON BACK PANEL

SERIAL PLATE LOCATED

BEHIND FRONT PANEL

Page 3

NM952R

FOR THE INSTALLER

Installation Limitations:

This ice system is designed to be installed indoors,
in a controlled environment:

Min Max

0

Air Temperature 50
(Not including the remote condenser)
Water Temperature 40
Water Pressure 20 PSIG 80 PSIG
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.

F 1000F

0

F 1000F

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, usually a
minimum of 6 inches. 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 the bin top according to the directions with
the bin top.

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 side. Secure the machine to the bin with the
hardware provided with the machine.

Remove the front panel and remove any shipping
blocks.

Note: Be sure to allow a 6" minimum space
above the top of the machine for service.

November 1992

Page 4

FOR THE INSTALLER: Remote Condenser

REMOTE CONDENSER

SPIRAL

EXCESS

TUBING

INSIDE

BUILDING

NM952R

Location

Limited to a 40 foot or a 25 foot length of
precharged refrigerant tubing connecting the ice
maker to the remote condenser. The condenser
must be above or level with the ice maker.

Select the best available location, protecting the
condenser from extremes of dirt, dust, and sun.

Meet all applicable building codes. Usually the
services of a licensed electrician are required.

Roof Attachment

1. Install and attach the remote condenser to the
roof of the building, using the methods and
practices of construction that conform to the local
building codes, including having a roofing
contractor secure the condenser to the roof.

2. Have an electrician connect the remote
condenser fan motor to the ice maker, using the
junction box at the back of the ice maker.

PRECHARGED LINE ROUTING

////////////////////////////CAUTION/////////////////////////////
Do not connect precharged tubing until all routing

and forming of the tubing is complete. See the
coupling instructions, page for connecting
instructions.

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

1. Each set of precharged refrigerant lines (either
25 foot or 40 foot) consists of a 3/8 inch diameter
liquid line and a 1/2 inch diameter discharge line.
Both ends of each line have quick connect
couplings, one end has a schrader valve
connection, that end goes to the condenser.

Note: The openings in the building ceiling or wall,
listed in the next step, are the minimum sizes
recommended for passing the refrigerant lines
through.

2. Have the roofing contractor cut a minimum hole
for the refrigerant lines of 1 3/4 inch. Check local
codes, a separate hole may be required for the
electrical power to the condenser.

////////////////////////////CAUTION/////////////////////////////
DO NOT KINK OR CRIMP REFRIGERANT

TUBING WHEN INSTALLING IT.
/////////////////////////////////////////////////////////////////////////

3. Route the refrigerant lines through the roof
opening.

Follow straight line routing whenever possible.
Any excess tubing MUST be retained within the

building.

4. Spiral the excess length of pre charged tubing
inside the building. Use a horizontal spiral (as
illustrated) to avoid any traps in the lines.

5. Have the roofing contractor seal the holes in
the roof per local codes.

Note: Precharged tubing contains a R-22 holding
charge. The entire refrigerant charge required for
the system is contained in the ice machine.

Tubing illustration shows tight spiral; a spiral in the
field depends on tubing limitations. Tight spiral not
required.

Traps in tubing not required, they are included as
part of the Scotsman condenser and ice machine.

LOCATE REMOTE

CONDENSER

ABOVE ICE MAKER

November 1992

Page 5

NM952R

FOR THE INSTALLER: Precharged Lines

COUPLING INSTRUCTIONS

/////////////////////////////CAUTION/////////////////////////////
The couplings on the sets of precharged lines are

self sealing when installed properly. Carefully
follow the instructions:

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

Initial Connections:

1. Remove the protector caps and plugs. Wipe the
seats and threaded surfaces with a clean cloth to
be certain that no foreign matter remains on them.

2. Lubricate the inside of the couplings, especially
the O-Rings with refrigerant oil.

••The 1/2 inch discharge line (schrader valve

end) goes to the remote condenser fitting
marked "discharge line".

••The 3/8 inch liquid line (schrader valve end)

goes to the remote condenser fitting marked
"liquid line".

••The 1/2 inch discharge line goes to the ice

maker fitting marked "discharge line".

••The 3/8 inch liquid line goes to the ice maker

fitting marked "liquid line".

Final Connections:

3. Begin tightening the couplings together by
hand, then using two wrenches (it is important that
ONLY the nut on the precharged lines be turned,
the other parts of the couplings must NOT be
allowed to turn or the process will tear out the
diaphragms and they will be loose in the
refrigeration system) tighten the coupling until it
bottoms out or a definite increase in resistance is
felt.

4. Using a marker or pen, mark a line lengthwise
from the coupling union nut to the bulkhead. Then
tighten the coupling and additional 1/4 turn. As the
nut turns, the line will show when 1/4 turn is made.

5. After all connections are made, and after the
king valve has been opened, check the couplings
for leaks.

SERVICE PORTS

REMOTE CONDENSER

3/8" LIQUID LINE

SCHRADER

VALVE

TO REMOTE

CONDENSER

1/2" DISCHARGE

LINE

NO SCHRADER

VALVE

TO ICE MAKER

November 1992

Page 6

FOR THE INSTALLER: Location

ICE MAKERS

TWO UNITS ON ONE

CONDENSER

EXCESS

PRECHARGED

TUBING INSIDE

BUILDING

NM952R

REMOTE

CONDENSER

ROOF

CUTAWAY

SERVICE

ACCESS

SERVICE ACCESS

SIDE AND BACK

WALL

CUTAWAY

November 1992

Page 7

FIELD

SUPPLIED

WATER FILTER

NM952R

FOR THE PLUMBER

CONFORM TO ALL APPLICABLE CODES

Water Inlet

HAND SHUT

OFF VALVE

CONNECT TO

COLD WATER

WATER INLET

3/8" MALE

FLARE

VENT ICE

MAKER

DRAIN,

3/4" FPT

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.

Drains

The cabinet has a 3/4" FPT drain.
connection. The drain is 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. Use
only 3/4" rigid tubing.

Storage Bin: A separate gravity type

drain needs to be run. Insulation of
this drain line is recommended.

VENT BIN DRAIN

3/4" FPT

FLOOR DRAIN

November 1992

Page 8

FOR THE ELECTRICIAN

CONFORM TO ALL APPLICABLE CODES

NM952R

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.
Voltage variation must remain within design
limitations, even under starting conditions.

TERMINAL STRIP

FOR REMOTE

CONDENSER

ICE MAKER

JUNCTION BOX

POWER

SUPPLY

Electrically the remote condenser fan motor is
connected to the ice maker at the contactor
terminals for the compressor and the fan motor
operates whenever the compressor operates.

Electrical connections are made at the junction
box at the back of the ice maker and at the
junction box on the remote condenser.

The remote condenser must be wired to the ice
maker in accordance with local and national
electrical codes with a minimum of 18 Awg. wire
with an ground bonding wire connected to the
ground screws provided in both the condenser and
machine field wiring boxes. All outdoor wiring
must be in rain proof conduit.

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.

RAIN PROOF

CONDUIT

GROUND

THE

CHASSIS

November 1992

Page 9

NM952R

FOR THE ELECTRICIAN: Fan Relay Kit

///////////////////////////WARNING/////////////////////////////
Do all wiring with the electrical power

disconnected.
/////////////////////////////////////////////////////////////////////////

To install the KCMR230 fan relay kit when using
(2) NM952R ice makers and one 230 volt, two
circuit remote condenser.

See the remote condenser nameplate for
current requirements to determine wire size
to be used for electrical hookup. Refer to
wiring diagram.

All external wiring should conform to the national,
state and local electrical codes. Usually an
electrical permit and services of a licensed
electrician will be required.

1. Mount the control box in a convenient location.

2. Attach a solid earth ground wire to the ground
screw.

3. Route connecting wires from the first ice maker
junction box

(marked condenser fan) and connect it to the
KCMR230 terminal strip marked: NO. 1 ICE
MACHINE.

4. Route connecting wires from the second
machine junction box

(marked condenser fan) and connect it to the
KCMR230 terminal strip marked: NO. 2 ICE
MACHINE.

5. Route connecting wires from KCMR230
terminal strip marked: TO REMOTE FAN and
connect at the remote condenser junction box.

6. Check phasing of the electrical circuit as follows:
A. The phasing of the wiring MUST now be

checked, as incorrect phasing will result in a failure
of the kit relay.

POSSIBLE LOCATION

FOR KCMR230

CONTROL BOX

November 1992

Page 10

NM952R

FOR THE ELECTRICIAN: Fan Relay Kit Phasing (Do After Start Up)

Below is an illustration of the KCMR230 terminal
strip. Note that each terminal is marked:
1-2-3-4-5-6. For proper phasing:

Terminals #1 and #3 must be connected to the
same side of the line (such as L1)

Terminals #2 and #4 must be connected to the
same side of the line (such as L2).

B. Make a test with a volt meter as follows:

1. Switch on ice maker #1 first, then switch on ice
maker #2.

(The compressors must be operating for this test.
Do this after start up.)

2. Test with a volt meter between terminals #2
and #4, then between terminals #1 and #3.
Compare the readings obtained to the ones in the
following list:

C. Test terminals 1-2 = Full Voltage (208-230)

Test terminals 1-3 = No voltage
Test terminals 2-3 = Full Voltage
Test terminals 2-4 = No voltage
Test terminals 3-4 = Full voltage
Test terminals 1-4 = Full voltage
D. If there is full voltage where there should be no

voltage, turn off ice maker #2, (both switches)
Then turn off ice maker #1 (both switches). The
connections at the KCMR230 terminal strip
marked ice maker #1 must be reversed (put the
wire that was on 1 on 2 and the wire that was on 2
on 1).

///////////////////////////WARNING/////////////////////////////
Do all wiring with the electrical power

disconnected.
////////////////////////////////////////////////////////////////////////

November 1992

Page 11

INSULATED

PRECHARGED

REFRIGERANT

TUBING

NM952R

FOR THE INSTALLER: Completed Installation

A typical installation should generally appear as
illustrated below. The remote condenser must be
located above the ice maker and the precharged
lines installed per the instructions on page 6.

ROOF

CUT-AWAY

November 1992

Page 12

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?

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 two units on one condenser,
has the relay kit been installed?

9. Is there a water shut off valve
installed near the machine?

10. Is the remote condenser
installed per local building codes,
and in a place where it has
adequate ventilation and minimal
solar heat gain?

11. Has all shipping material and
literature (inside the front panel)
been removed from the units?

12. Have the remote condenser
and precharged lines been
properly installed?

13. Has the electrical connection
between the ice maker and the
condenser been made?

14. Verify that the master switch is in the OFF
position.

REMOTE

CONDENSER

SECURED?

PLUMBING?

15. Switch on the electrical power.

16. Refer to Pre-Start instructions, the next page.

NM952R

ROOF

HOLES

SEALED?

POWER

SUPPLY?

LEVELED?

November 1992

Page 13

NM952R

START UP

Pre-Start Inspection

1. Remove the front, left, and right side service
panels.

2. Check that any styrofoam shipping blocks have
been removed.

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 (remote condenser).

Start Up

1. Go through the pre-start 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. Open the King Valve.

4. Turn 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 liquid line valve

will open, the low pressure control will close and
the compressor will start.

4. Check that the refrigerant lines are properly
installed.

5. Check that the electrical power has been on for
at least 12 hours and that the compressor dome is
warm.

6. Check that the unit is installed correctly
according to the final check list on page 13.

6. The unit should soon be making ice, if desired
the low side pressure may be checked, it should
be 25 psig + or - 2 psig. The discharge pressure
will depend upon air and water temperatures, but
should be between 200 psig and 280 psig.

7.

THERE ARE NO ADJUSTMENTS TO MAKE,

so replace the panels.

8. Clean and/or sanitize the storage bin interior,
wipe off the exterior with a clean, damp cloth.

9 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.

5. The remote condenser fan turns, and the
condenser begins to discharge warm air.

10. Fill out the manufacturers registration card,
and mail it to the Scotsman Factory.

November 1992

Page 14

COMPONENT DESCRIPTION

CLEANING

DRAIN TUBE

EVAPORATOR

GEAR MOTOR

COMPRESSOR

ICE CHUTE

NM952R

Control Box: Contains the electrical controls that

operate the machine.

High Pressure Cut Out: A manual reset switch

sensing the high side refrigeration pressure. It is
set to shut the machine off at 400 psig.

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.

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.

CONTROL BOX

Ice Discharge Chute: Directs the ice produced

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.
Expansion valve: The refrigerant metering

device.

EXPANSION VALVE

WATER LEVEL

SENSOR

RESERVOIR

ICE LEVEL

SENSOR

HIGH PRESSURE

CUT OUT

November 1992

Page 15

NM952R

COMPONENT DESCRIPTION: Control Box

Contactor:

connecting the compressor and the remote
condenser fan motor to the power supply.

A definite purpose contactor

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 liquid line valve.

ON/OFF SWITCH

PUMP DOWN CONTROL

Transformer:

board.

Pump Down Control:

pressure switch connected to the low side of the
refrigeration system. Controls the compressor.

Supplies low voltage to the circuit

An automatic reset

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

POTENTIAL RELAY

TRANSFORMER

CIRCUIT

BOARD

CONTACTOR

November 1992

Page 16

ELECTRICAL SEQUENCE

NM952R

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 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 liquid line relay and auger motor relay

become energized, connecting power to the
liquid line solenoid coil and to the windings of
the auger motor.

••The liquid line solenoid opens, raising the low

side pressure.

••The pump down control closes.

••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 liquid line solenoid closes, lowering the

suction pressure.

••The pump down control opens.

••The compressor contactor opens

••The compressor stops

••The auger motor is run by the circuit board for 2

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:

••The high pressure control will stop the machine

immediately if it opens. It is manually reset at

the control.

••The spout switch will stop the machine

immediately if it opens. It is a manual reset.

••The master switch is the manual control for the

complete machine, but it is not a service

disconnect.

November 1992

Page 17

NM952R

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 them goes out the bottom of the
reservoir tank to the bottom of the evaporator.

Reservoir overflow or evaporator condensation is
routed to the drain.

ADJUSTMENT OF THE

WATER LEVEL

RESERVOIR

WATER

INLET

WATER RESERVOIR

DRAIN TUBE

WATER LEVEL

DRAIN

November 1992

Page 18

OPERATION: Refrigeration

THERMOSTATIC

EXPANSION

VALVE

NM952R

Beginning at the compressor, the refrigerant is
compressed into a high temperature gas. The
discharge line directs this gas to the condenser.
At the remote condenser the gas is cooled by air
and it then condenses into a liquid. This high
pressure liquid then goes through the liquid line to
the head pressure control valve, into the receiver,
through the liquid line valve and then through the
expansion valve.

The thermostatic expansion valve meters liquid
refrigerant into the evaporator, the volume of liquid

Refrigeration Schematic

refrigerant depending upon the temperature of the
evaporator; warmer evaporators get more
refrigerant and colder evaporators get less.

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.

REMOTE CONDENSER

DISCHARGE

LINE

HEAD

PRESSURE

CONTROL

VALVE

LIQUID LINE

DETAIL OF HEAD

PRESSURE CONTROL

VALVE

LIQUID LINE

VALVE

EVAPORATOR

KING

VALVE

SUCTION

LINE

RECEIVER

COMPRESSOR

November 1992

Page 19

THERMOSTATIC

EXPANSION

VALVE

EVAPORATOR

REMOTE CONDENSER

NM952R

OPERATION: Refrigeration

Low Condensing Temperature

The refrigeration system under low condenser air
temperatures is much the same as it is under
higher temperatures, with the exception that the
resulting low head pressures cause the head
pressure control to close off the liquid line between
the condenser and the receiver. This forces more

DISCHARGE

LINE

LIQUID LINE

refrigerant into the condenser (with a small amount
of discharge gas going into the receiver to
maintain pressure until the head pressure is built
back up to the rated gauge pressure of 220 psig).
At that pressure the valve opens up the liquid line
from the condenser to the receiver.

Refrigeration Schematic

DETAIL OF HEAD

PRESSURE CONTROL

VALVE

HEAD

PRESSURE

CONTROL

VALVE

LIQUID LINE

VALVE

KING

VALVE

SUCTION

LINE

RECEIVER

COMPRESSOR

November 1992

Page 20

OPERATION: Refrigeration

REMOTE CONDENSER

EVAPORATOR

THERMOSTATIC

EXPANSION

VALVE

NM952R

PUMP DOWN

During the pump down cycle (usually initiated by
the circuit board de-energizing the liquid line valve)
the discharge gases flow through their normal path
to the remote condenser, through the head
pressure control, and into the receiver. At this

DISCHARGE

LINE

LIQUID LINE

point the refrigerant flow is stopped by the closed
liquid line valve. This action forces the refrigerant
into the receiver and keeps it out of the
compressor. The pump down continues until the
low pressure control turns the compressor off.

Refrigeration Schematic

HEAD

PRESSURE

CONTROL

VALVE

LIQUID LINE

VALVE

KING

VALVE

SUCTION

LINE

RECEIVER

COMPRESSOR

November 1992

Page 21

NM952R

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 process.

//////////////////////////////////////////////////////////////////////////
ICE MAKING SYSTEM: In place cleaning

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

2. Remove screws and front and top panels.

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 solution should be
between 90 and 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 ice making 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 panels.

November 1992

Page 22

MAINTENANCE AND CLEANING

NM952R

/////////////////////////////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.

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
build-up.

SLIDE UP

TO REMOVE

RESERVOIR

WATER LEVEL

SENSOR

ICE CHUTE

ICE LEVEL

SENSORS

SLIDE LEFT TO

REMOVE

Inspect the assembly, looking for wear

4. Clean the remote condenser. Use a vacuum
cleaner or coil cleaner if needed.

Do NOT use a wire brush.

5. Check and tighten all bolts and screws.

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

CAUTION: THE TIP

IS MADE OF GLASS

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

3. The top bearing in the breaker should also be
checked at least

Check the breaker bearing by:

two times per year.

••removing the ice chute cover

••unscrewing the ice sweep

••removing the water shed

••

unscrewing the breaker cover (left hand thread)

••unscrewing the auger stud

ICE

SWEEP

BREAKER

COVER

November 1992

Page 23

NM952R

MAINTENANCE AND CLEANING

In some areas the water supply to the ice maker
will have a great deal of minerals in it, and that will
result in an evaporator and auger becoming
coated with these minerals, requiring a more
frequent removal 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.

ALLEN

SCREWS

BREAKER

& BEARING

& AUGER

ASSEMBLY

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 and
replacement of these parts, see REMOVAL
AND REPLACEMENT.

1. To remove the auger, remove the front and top
panels.

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 screws holding breaker to
evaporator.

6. Pull up to remove auger.
After the auger has been removed, allow the auger

to dry; if the auger is not bright and shiny, it must
be cleaned.

Clean the auger and evaporator as required.
DO NOT HONE THE EVAPORATOR.

7. Replace the water seal.

8. Reverse to reassemble.

November 1992

Page 24

SERVICE DIAGNOSIS: Condition - No Ice Being Produced

NM952R

STATUS:

NOTHING OPERATES

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 2 reset switches (spout switch and high pressure): depress and release each

switch. If the unit still does not start, check the spout for too much ice, or high side pressure.
D. Check the high pressure cut out switch.

1. This pressure switch opens at 400 psig. Check the high side pressure, reset the switch and observe that
the fan is forcing air through the condenser. If the switch opens at pressures below 400 psig, replace the
switch.

If the pressures rise above the trip out point, and the unit shuts down:

a. Check for adequate air flow. Clean the condenser. 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.
b. Check the head pressure control valve, it should be maintaining a head pressure
above 220 psig. If the unit has the correct charge, and the condenser is clean, and the
refrigerant lines are not kinked or twisted, and the condenser is not overheated by
external heat loads, the head pressure should be under the trip out point of the head
pressure control switch. If all of the above are found to be good, and the machine
trips out on high head pressure, replace the head pressure control valve.

E. Check the spout switch.

1. This switch will open if the bin control (ice level sensor) does not shut the machine off when the ice
storage bin is full of ice: ice backs up in the ice chute, and internal pressure opens the switch, stopping the
machine. If, after resetting the switch, the machine does start, check:

a. The ice level sensors, they may need cleaning (see maintenance).
b. The circuit board, see next page.

F. Check the water level. If there is not enough water in the reservoir, the water level sensor will
keep the machine from starting.

a. Check the water level, restore/adjust if low.
b. Check the water level sensor, clean if dirty, (see maintenance).
c. Check the circuit board, see next page.

If the machine does not start, see the next page.

November 1992

Page 25

NM952R

SERVICE DIAGNOSIS: Condition - No Ice Being Produced

STATUS:

NOTHING OPERATES

G. 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.

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

a
The line side should have between 208-230 volts. If the line side has the correct

voltage and the load side does not, replace the transformer.

2. If the transformer is good, and the

. Remove sensors by sliding them sideways out of the ice chute. Visually inspect

a

them, clean if needed.

. Look through the ice chute "eye" hole for something blocking the ice chute.

b
c. If the unit still does not run, replace the ice level sensors.

. If the bin empty light is still OFF, check the circuit board.

d

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

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

Tester Model NM1 into the circuit board

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.

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

3

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

. Replace the water level sensor. If the no water light is still on, check that the

c
"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 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

bin empty light is OFF, check the ice level sensors.

(see page 36).

MORE INFORMATION ON THE TESTER MAY BE FOUND ON PAGE 36.

November 1992

Page 26

SERVICE DIAGNOSIS: Condition - No Ice Being Produced

NM952R

STATUS:

GEARMOTOR OPERATES, COMPRESSOR DOES NOT

A. Check the pump down control switch.

1. This pressure switch opens at 6-10 psig, and closes at 16-20 psig. If open check the low side pressure,

if after running the machine the switch opens at a pressure higher than 10 psig, replace the switch.

The low pressure control switch could remain open for any of the following reasons: Low refrigerant

charge, auger not turning, restricted system, TXV not opening, liquid line valve not opening.

2. Check the low side pressure, the low pressure cut out switch should remain closed at any pressure

higher than 10 psig. If less than that:

a. Check if the

Check for internal damage, repair and replace in the machine.
b. Check for low charge, add some refrigerant, if the unit begins to operate, (normal low
side pressure being about 25 psig) stop and look for a leak, recover, repair, replace the drier,
evacuate, and weigh in the nameplate charge. If, with added charge,
the unit does

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

nameplate charge.

Check for a

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

c. Check the liquid line solenoid valve, it should have power to it, if not:

Check the connections on the circuit board. The liquid line (or compressor) relay

on the circuit board may have failed. If so, replace the circuit board.

If there is power to the valve, the coil may be open, or the valve jammed, replace

the valve.

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

not operate:

Thermostatic Expansion Valve that does not open, if defective,

November 1992

Page 27

NM952R

SERVICE DIAGNOSIS: Condition - Low Ice Production

STATUS:

EVERYTHING IS OPERATING

A. Check the condenser for dirt. Clean as required. Check the head pressure. If the head
pressure is very high:

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

2. The refrigerant may contain non condensable gases, recover, evacuate, and recharge per nameplate.

3. Check the interconnecting refrigerant tubing for kinks or twists.
Check that the discharge and liquid lines are insulated, and do not touch each other
where not insulated.

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 25 psig. If low, assume a refrigerant leak, locate, recover,

repair and recharge.

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

4. Check the insulation on the evaporator. It should be dry, with no wet spots or frost. If the insulation has

failed: replace the evaporator or add extra insulation in the form of foam tape
to the evaporator.

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.

D. Refrigerant charge

On this model the refrigerant charge is adequate whenever the receiver has enough liquid refrigerant to
maintain liquid refrigerant at the TXV. HOWEVER, the condensing temperature will have a definite bearing
on this. A unit with a marginal charge in summer, will be
drops. The only correct way to charge this unit is to weigh in the nameplate charge.

undercharged when the outside air temperature

November 1992

Page 28

FLOAT

ASSEMBLY

NM952R

REMOVAL AND REPLACEMENT: Water Reservoir & Bin Controls

WATER RESERVOIR

1. Shut off the water supply to the ice maker.

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 ice maker.

8. Reverse to reassemble.

SLIDE BIN

CONTROLS IN

AND OUT

ICE

CHUTE

FLOAT

MOUNTING

FLANGES

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 ice
chute.

November 1992

Page 29

Step 5-c and Step 6

NM952R

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. Unscrew the 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

ICE

SWEEP

AUGER

STUD

ALLEN

SCREWS

November 1992

Page 30

REMOVAL AND REPLACEMENT: Auger

DRIVE SLIDE UP AGAINST
STOP TO LOOSEN AUGER

NM952R

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, or, if that is not

possible, the gearmotor and freezer assembly
must be pulled part of the way out from the
cabinet. To do that:

a. Unclip the electrical wires from the hanger near
the drive motor.

b. Remove the bolt holding the gearmotor plate.
c. Pull the assembly out.

2. 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.

BREAKER

BEARING

ASSEMBLY

Note: If the
auger is stuck,
the breaker must
be removed from
the auger.

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

a. 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 on breaker to remove from auger.
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:

a. 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.
//////////////////////////////////////////////////////////////////////////
b. 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.

STOP

SLIDE HAMMER

PULLER REMOVING

AUGER

THREAD

INTO

AUGER

November 1992

Page 31

WATER SEAL

RETAINING

RING

NM952R

REMOVAL AND REPLACEMENT: Water Seal

To Remove the Water Seal:

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

1. The gearmotor/evaporator assembly will have to

be pulled away from the machine (if not yet done).

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.

REMOVAL OF THE WATER SEAL

November 1992

Page 32

REMOVAL AND REPLACEMENT: Refrigeration System

NM952R

General:

••

Scotsman recommends that any work on the
refrigeration system only be done when it is
certain that the system needs repair.

••The access valves are at the front of the

cabinet. To use them, remove the cap from the
valve ports and the cap from the top of the
valve body. Attach gauge manifold and then
use a 3/16" allen wrench to loosen the valve.
Although pressure readings may be taken with
the valve cracked open, several turns are
required to completely open the valve.

valve and replace caps when the job is
finished.

ALLEN WRENCH

Torque Stem to

6-8 ft. lbs.

Torque Cap to

8-12 ft. lbs.

ACCESS

VALVE

Torque Cap to

7-12 ft. lbs.

••Refrigerant should not be added except as a

way to determine the proper operation of the
product. If the system was low on refrigerant,
there is a leak, and it must be found and
repaired.

••Although this system uses R-22, it must not

be vented to the atmosphere.

••This system has a critical charge, it must be

recharged with the correct amount of
refrigerant as listed on the nameplate of the
ice machine, or performance will suffer.

••Anytime the refrigeration system has been

opened, the dryer should be replaced.

••When brazing the tubing connections to the

thermostatic expansion valve, the component
must be protected by heat sink material.

Close

Specifically:

Recover, reclaim or recycle refrigerant. Although
the method chosen is up to the service
company, Scotsman recommends reclaim.
There are various mechanical devices that may
be used to recycle refrigerant at the field level,
however, Scotsman requires that any refrigerant
placed into a Scotsman ice machine meet ARI
spec 700-88. Reclaim programs are available
thru most refrigerant wholesalers.

Use conservation minded service procedures:

••

Refrain from checking refrigeration pressures
without reason. There are many ways to
determine the proper operation of a
Scotsman ice machine without using
refrigerant gauges. Visual inspection of the
water system, amp draw, voltage, and other
techniques will lead to proper diagnosis.

••If gauges must be used, do not always check

the high side pressure. If the condenser is
clean and seems to be operating correctly, it
most likely is. The low side pressure is much
more important on an ice machine than is the
high side.

••If gauges must be used, use very short

hoses. Minimal refrigerant discharged into the
hoses equals minimal refrigerant discharged

into the air.
If using recycled refrigerant, it must meet ARI
spec 700-88 or have been cleaned by a
machine capable of attaining ARI spec 700.

November 1992

Page 33

NM952R

REMOVAL AND REPLACEMENT: Evaporator

Charging Procedures

Extra care must be taken when recharging this
remote system. No liquid refrigerant may be
placed in the system at the compressor.

To Replace the Evaporator:

(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”)
resweat the tubing 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.

DO NOT use the access valves at the front of the
unit for weighing in the charge. All liquid refrigerant
must be weighed into the receiver through the
“front seated” king valve.

PLACE A BEAD OF
FOOD GRADE
SEALANT HERE

Head Pressure Control Valve

1. Purge system of refrigerant

2. Break off process tube on the top of the OLD
head pressure control valve.

3. Unsweat old valve from tubing.

4. Unsweat old dryer from tubing.

5. Install new valve in place, check for correct
connections and be sure the number on the side of
the valve is “220"

6. Wrap the new valve body in wet cloths to heat
sink the valve body.

7. Sweat in the new valve and the new dryer.

8. Evacuate the system, and weigh the nameplate
charge into the receiver.

November 1992

Page 34

REMOVAL AND REPLACEMENT: Gearmotor Assembly

CHARGING

CYLINDER

NM952R

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 ice maker.

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 16 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.

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

Charging Procedures

Extra care must be taken when recharging this
remote system. No liquid refrigerant may be
placed in the system at the compressor. DO NOT

RECEIVER

use the access valves at the front of the unit for
weighing in the charge. All liquid refrigerant must
be weighed into the receiver through the “front
seated” king valve".

FRONT SEATED

KING VALVE

SERVICE PORT

November 1992

Page 35

LIGHT GOES ON

NM952R

CIRCUIT BOARD TESTING

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.)
///////////////////////////////////////////////////////////////////////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.
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

Bin Control

Note: Testing is done with the
electrical power on, the master switch on, and all
the 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.

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 OFF

LIGHT

GOES ON

SWITCH TO

“BIN EMPTY”

November 1992

Page 36

CIRCUIT BOARD TESTING

NM952R

Water Level

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

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

LIGHT ON

WATER SENS

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.

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”

November 1992

Page 37