Ice-O-Matic GEMD520A Service Manual

Installation and Service Manual

GEMD520-GEMD525-GEMD540 Series

Ice-O-Matic
11100 East 45th Ave
Denver, Colorado 80239
Part Number 9081422-01 Date 2/11

Ice-O-Matic







Parts and Labor

Domestic & International Limited Warranty

Mile High Equipment LLC (the “Company”) warrants Ice-O-Matic brand ice machines, ice dispensers, remote condensers, water filters, and ice storage
bins to the end customer against defects in material and factory workmanship for the following:

 Cube ice machines,”GEM” model compressed ice machines ,

“MFI” model flake ice machines and remote condensers. ­Thirty-six (36) months parts and labor

 “EF” model flake ice machines and GEMD maker dispensers-

Twenty-four (24) months parts and labor

 CD model dispensers - Thirty-six (36) months parts and labor

An additional twenty-four (24) month warranty on parts (excluding labor) will be extended to all cube ice machine evaporator plates and compressors,
“GEM” model compressed ice machine compressors, and “MFI” model flake ice machine compressors from the date of original installation. An additiona l
thirty-six (36) month warranty on parts (excluding labor) will be extended to all “EF” model flake ice machine and “GEMD” maker dispenser compres sors
from the date of original installation. The company will replace EXW (Incoterms 2000) the Company plant or, EXW (Incoterms 2000) the Company­authorized distributor, without cost to the Customer, that part of any such machine that becomes defective. In the event that the Warranty Registration
Card indicating the installation date has not been returned to Ice-O-Matic, the warranty period will begin on the date of shipment from the Company.
Irrespective of the actual installation date, the product will be warranted for a maximum of seventy-two (72) months from date of shipment from the
Company.

ICE-model cube ice machines which are registered in the Water Filter Extended Warranty Program will receive a total of eighty-four (84) months parts
and labor coverage on the evaporator plate from the date of original installation. Water filters must be installed at the time of installation and registered
with the Company at that time. Water filter cartridges must be changed every six (6) months and that change reported to the Company to maintain the
extended evaporator warranty.

No replacement will be made for any part or assembly which (I) has been subject to an alteration or accident; (II) was used in any way which, in the
Company’s opinion, adversely affects the machine’s performance; (III) is from a machine on which the serial number has been altered or removed; or,
(IV) uses any replacement part not authorized by the Company. This warranty does not apply to destruction or damage caused by unauthorized service,
using other than Ice-O-Matic authorized replacements, risks of transportation, damage resulting from adverse environmental or water conditions,
accidents, misuse, abuse, improper drainage, interruption in the electrical or water supply, charges related to the replacement of non-defective parts or
components, damage by fire, flood, or acts of God.

This warranty is valid only when installation, service, and preventive maintenance are performed by a Company-authorized distributor, a Compa ny­authorized service agency, or a Company Regional Manager. The Company reserves the right to refuse claims made for ice machines or bins used in
more than one location. This Limited Warranty does not cover ice bills, normal maintenance, after-install adjustments, and cleaning.
Limitation of Warranty

This warranty is valid only for products produced and shipped from the Company after March 201 1. A product produced or installed before that date
shall be covered by the Limited Warranty in effect at the date of its shipment. The liability of the Company for breach of this warranty shall, in any case,
be limited to the cost of a new part to replace any part, which proves to be defective. The Company makes no representations or warranties of any
character as to accessories or auxiliary equipment not manufactured by the Company. REPAIR OR REPLACEMENT AS PROVIDED UNDER THIS
WARRANTY IS THE EXCLUSIVE REMEDY OF THE CUSTOMER. MILE HIGH EQUIPMENT SHALL NOT BE LIABLE FOR ANY INCIDENTAL OR
CONSEQUENTIAL DAMAGES FOR BREACH OF ANY EXPRESS OR IMPLIED WARRANTY ON THIS PRODUCT. EXCEPT TO THE EXTENT
PROHIBITED BY APPLICABLE LAW, ANY IMPLIED WARRANTY OR MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ON THIS
PRODUCT IS LIMITED IN DURATION TO THE LENGTH OF THIS WARRANTY.

Filing a Claim
All claims for reimbursement must be received at the factory within 90 days from date of service to be eligible for credit. All claims outside this time
period will be void. The model, the serial number and, if necessary, proof of installation, must be included in the claim. Claims for labor to replace
defective parts must be included with the part claim to receive consideration. Payment on claims for labor will be limited to the published labor time
allowance hours in effect at the time of repair. The Company may elect to req uire the return of components to validate a claim. Any defective part
returned must be shipped to the Company or the Company-authorized distributor, transportation charges pre-paid, and properly sealed and tagged. Th e
Company does not assume any responsibility for any expenses incurred in the field incidental to the repair of equipment covered by this warranty. The
decision of the Company with respect to repair or replacement of a part shall be final. No pe rson is authorized to give any oth er warranties or to assume
any other liability on the Company’s behalf unless done in writing by an officer of the Company.

GOVERNING LAW
This Limited Warranty shall be governed by the laws of the state of Delaware, U.S.A., excluding their conflicts of law principles. The United Nations
Convention on Contracts for the International Sale of Goods is hereby excluded in its entirety from application to this Limited Warranty.

Mile High Equipment LLC, 11100 East 45th Avenue, Denver, Colorado 80239 [phone]

Ice storage bins -Twenty-four (24) month parts and labor

IOD model dispensers - T wenty-four (24) months parts, Twelve (12) months

labor

Water filter systems - Twelve (12) months parts and labor (not including filter

cartridges)

March 2011

Ice‐O‐Maticisdevotedtosustainability ineveryaspectofourbusiness.Sotohelpoffsetour
carbonfootprint,weworkwithAmericanForeststoplantatreeforeveryicemachinewe
sell.Ourultimategoalistoplant150,000treesoverthenextseveralyears.



INTRODUCTION

GEMD520-GEMD525-GEMD540

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 maker-dispenser.

The machine is a combination GEM ice maker and
countertop dispenser, with the option of wall
mounting.

The ice making section is equipped with the
following features: electronic controls for bin level
and low water; thermostatic expansion valve; front
service for most components; and R-404A
refrigerant. The ice dispensing section is a
seamless plastic storage bin, with a stainless steel
rotating vane to sweep the ice into the dispensing
chute.

Table of Contents

FOR THE INSTALLER: Specifications ····································Page 2

FOR THE INSTALLER: Environmental Limitations······························Page 3

FOR THE INSTALLER ············································Page 4

FOR THE INSTALLER: Wall Mount Kit····································Page 5

FOR THE PLUMBER·············································Page 6

FOR THE ELECTRICIAN ··········································Page 7

FOR THE INSTALLER: Final Check List ···································Page 8

INITIAL START UP ··············································Page 9

COMPONENT DESCRIPTION ········································Page 10

COMPONENT DESCRIPTION ········································Page 11

COMPONENT DESCRIPTION: Control Box ·································Page 12

ELECTRICAL SEQUENCE··········································Page 13

OPERATION: Water ·············································Page 14

OPERATION: Refrigeration ·········································Page 15

OPERATION: Ice Vending ··········································Page 16

DISPENSE AREA SANITATION ·······································Page 17

CLEANING and SANITIZING ········································Page 18

MAINTENANCE AND CLEANING ······································Page 19

SERVICE DIAGNOSIS ············································Page 21

SERVICE DIAGNOSIS: Circuit Board ····································Page 23

REMOVAL AND REPLACEMENT ······································Page 24

REMOVAL AND REPLACEMENT: Bearing And Breaker ··························Page 25

REMOVAL AND REPLACEMENT: Water Seal································Page 27

TO REMOVE AND REPAIR THE GEARMOTOR ASSEMBLY························Page 29

REFRIGERATION SERVICE: R-404A (HP62) ································Page 30

REFRIGERATION SERVICE·········································Page 31

CIRCUIT BOARD SERVICE ·········································Page 32

LIQUID CHARGING ·············································Page 32

Note this symbol when it appears.

It marks a possible hazard.

Page 1

GEMD520-GEMD525-GEMD540

FOR THE INSTALLER: Specifications

This ice maker-dispenser is designed to be
mounted on a machine stand, or a countertop, or
using wall mounting kit KWB3, hung from a wall.
The sink may be retained, or removed and the
optional longer splash panel (KSP5) installed in
place of the original. Instructions for each kit are
included in this service manual.

20.5"

14.06"

2.56"

1.88"dia

Before beginning the installation, check that all the
materials and kits required are available at the
installation location.

NAMEPLATE

on back panel

3.54"

4.5"

3/8" FPT
condenser
Water Inlet
(Water Cooled)

ELECTRICAL JUNCTION BOX

3/8" Flare
Potable Water Inlet

Optional for water and

drain lines

22.5"

Serial Number Plate

inside on upper base

SPECIFICATIONS

Model Number Dimensions (w/o stand)

H”xW”xD”

GEMD540A

48.5 x 26 x 20.5

Basic

Electric

115/60/1 Air 24 19.3 25

1/2" FPT
Cond. Drain
(Water Cooled)

Cond.

Type

3/4" FPT
Drain

Ref. Charge,

R-404A in ounces*

12.27"

1.12"

Minimum Circuit

Ampacity

3.12"

GEMD520A 41.0 x 26 x 20.5 115/60/1 Air 24 19.3 25

GEMD525A

41.0 x 26 x 20.5 230/50/1 Air 24 11.5 15

* Always check the nameplate for charge info.

5.12"

6.43"

Maximum
Fuse Size

Page 2

GEMD520-GEMD525-GEMD540

FOR THE INSTALLER: Environmental Limitations

Installation Limitations

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

Minimum Maximum

Air Temp 50

Water Temp 40

0

F. 1000F.

0

F. 1000F.

Water Pressure 20 PSI 80 PSI

Voltage (115v) 104 126

Operating the machine outside of the above
limitations, or outdoors, is potentially damaging to
the machine; also it is misuse of the machine,
which may void the warranty.

Ice-O-Matic ice machines are designed and
manufactured with the highest regard for safety
and performance. They meet or exceed the
standards of UL and NSF.

Ice-O-Matic assumes no liability or responsibility of
any kind for products manufactured by Ice-O-Matic
that have been altered in any way, including the
use of any part and/or other components not
specifically approved by Ice-O-Matic.

Ice-O-Matic reserves the right to make design
changes and/or improvements at any time.

Specifications and design are subject to change
without notice.

Service Limitations

Do not install in a location where the top of the
machine is within 6" of a fixed ceiling. Do not install
air cooled models in a location where there is less
than 6" clearance to the left and right of the
cabinet.

CEILING

CUT AWAY

WALL

CUT AWAY

SPACE
ABOVE

FOR

SERVICE

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 greatly 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.

6" SPACE

FOR AIR

(A/C)

Airflow

SPACE

FOR

UTILITIES

6" SPACE

FOR AIR

(AIR COOLED)

Page 3

GEMD520-GEMD525-GEMD540

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
above and behind it for service. Air cooled models
require a minimum of 6 inches to the left and right
of the machine for air circulation.

Machine Stand Installation

Tip the stand on its back and install the legs, return
the stand to the upright position. Adjust leg levelers
so that the stand does not “rock”.

Counter Top or Machine Stand Installation

The base of the icemaker-dispenser must be
sealed to the object it rests upon. Food grade
silastic sealant is recommended.

Place a bead of the sealant on the machine stand
or counter top to match the outside edge of the
cabinet base and sink.

The icemaker-dispenser is heavy: use of a
mechanical hoist is recommended to lift it to the
height required to install it.

The DMS machine stand has holes in the top that
match up with threaded holes in the
icemaker-dispenser. Place the cabinet onto the
machine stand, so that the unit is lined up with the
holes. Secure the ice maker-dispenser to the
machine stand with bolts and washers.

In both counter top and machine stand
installations, wipe off and neatly smooth any
excess sealant. Level the machine stand and
cabinet.

Unpack and install the sink brackets. Fit the sink
assembly onto the two sink brackets, and press
onto the bead of sealant. Wipe off and neatly
smooth any excess sealant from under the sink
edge.

SEAL THE

UNIT TO

THE

COUNTER

OR STAND

Unpack and install the water spout.

Water Spout: Slide over stainless steel water

discharge tube, locate and match up with notches
in the base. Rotate clockwise to move spout into
installed position.

Water
Spout

Page 4

GEMD520-GEMD525-GEMD540

FOR THE INSTALLER: Wall Mount Kit

CAUTION

It is recommended that the wall mounting
installation be done by an experienced contractor.
The weight of the machine when in use may
exceed 350 pounds. The unit should be mounted
on a solid, rigid wall with proper fasteners for that
type of wall and of adequate strength to support
the weight of the machine when in use.

Clearance between the wall and the icemaker is a
maximum of 1 inch. Check utility connections first.
The electrical junction box will have to be removed,
and the electrical connections made inside the
cabinet in compliance with local codes. The
plumbing connections may be made through the
base, or at either side through the pre-punched
holes, using standard plumbing practices.

Interior plumbing lines must be disconnected from
the original connections and plugged when
routing through the side or base.

1. Remove machine top. Attach bracket “A” to
machine using (3) nuts, (3) flat washers, (3) lock
washers, and (3) 5/16-18 bolts received with the
kit.

GEMD540=38.6"

GEMD525=30"

7.83

1" CLEARANCE

BASE
HOLE

SIDE

ROUTIN

16"

16"

A

DO NOT LIFT ON SINK

2. Mount brackets “B” and “C” to the wall at the
dimensions shown for the unit. (hardware for this is
not included).

B

Use fasteners and wall of sufficient strength to
carry the use and weight of the
icemaker-dispenser.

3. Lift unit up and hook bracket “A” over bracket

12"

12"

C

“B”. Slide unit until the two remaining holes are
aligned and secure with the remaining (2) 1/4-20
bolts, flat washers and lock washers.

Page 5

GEMD520-GEMD525-GEMD540

FOR THE PLUMBER

CONFORM TO ALL APPLICABLE CODES

Water Inlet

Air Cooled Models: The recommended water
supply is clean, 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 Treatment: In most areas, a water filter of
some type will be useful. In areas where the water
is highly concentrated with minerals the water
should be tested by a water treatment specialist,
and the recommendations of the specialist
regarding filtration and/or treatment should be
followed.

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 80 psig.

WATER INLET

CABINET

DRAIN

OPTIONAL

WATER

FILTER

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. Use only 3/4" rigid tubing.

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.

WATER INLET

SHUT OFF

VALVE

VENTED

DRAIN TUBE

FLOOR DRAIN

WATER COOLED DETAIL

Condenser

WATER INLET

Page 6

POTABLE

WATER INLET

CABINET

DRAIN

Condenser

DRAIN

FOR THE ELECTRICIAN

CONFORM TO ALL APPLICABLE CODES

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.

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.

GEMD520-GEMD525-GEMD540

INDIVIDUAL CIRCUIT
FOR ICE DISPENSER

JUNCTION

BOX

Page 7

GEMD520-GEMD525-GEMD540

FOR THE INSTALLER: Final Check List

1. Is the icemaker-dispenser installed indoors, in a
location where the air and water temperatures are
controlled, and where they do not go beyond
design limitations?

2. Is there an electrical disconnect (switch or plug
as required) within sight of the installed machine?
Is the machine on a separate circuit? Has the
voltage been checked and compared to nameplate
requirements?

3. Have all of the plumbing connections been
made and checked for leaks?

4. Has the machine been leveled?

5. Is there a minimum of 6 inches of clearance at
the left and right sides of an air cooled machine?

6. Is there a minimum of 6 inches of clearance at
the top and back of the machine for service and
utility connections?

BACK VIEW OF COMPLETED INSTALLATION

ELECTRICAL?

LEVELED?

ICEMAKER

DISPENSER

PLUMBING?

Wall mounted only: Is the machine properly
installed and secured to the wall?

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

MACHINE

STAND

Page 8

GEMD520-GEMD525-GEMD540

INITIAL START UP

Pre Start Inspection

1. Remove the two front panels.

2. Check that all shipping blocks have been
removed.

3. Remove any and all packing tape (check inside
the storage bin).

4. 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 on air
cooled models turns freely.

5. Check that the machine is installed correctly
according to the final check list.

Start Up

1. Go through the pre start inspection.

2. Open the water 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 automatic; there will be a short (15
second) delay before the machine starts.

4. On air cooled models, warm air will begin to flow
from the condenser. Water cooled models will
begin to discharge warm water down the drain.

5. The unit should soon be making ice. If desired,
the low side pressure may be checked: it should
be 38 PSIG + or - 2 PSIG.

The air cooled discharge pressure will depend
upon air and water temperatures, but should be
between 240 PSIG and 340 PSIG.

Water cooled discharge pressure should be about
245 PSIG. If needed, adjust the water regulating
valve.

The above numbers are for new, clean machines.
Field values may be somewhat higher or lower.

6. There are no adjustments to make, so replace
the panels.

8. Switch off the icemaker-dispenser, remove the
top panel and the top of the ice storage bin.
Sanitize the interior of the ice storage bin by wiping
it with a mixture of 1 ounce of household bleach to
2 gallons of water, allow to air dry. Replace all
covers and panels. Switch the icemaker-dispenser
back on.

9. Give the owner/user the service manual, instruct
him/her in the operation and maintenance
requirements of the unit. Make sure they know who
to call for service.

10. Fill out the Customer Evaluation and Warranty
Registration form, and mail it in to Ice-O-Matic.

7. Check ice dispensing by holding a container in
front of the Touch Free ice sensor (just below the
ice delivery spout). Ice should flow from the spout
when a container is present, and stop dispensing
when the container is removed.

Page 9

GEMD520-GEMD525-GEMD540

COMPONENT DESCRIPTION

High Pressure Cut Out Switch: A manual reset
switch sensing the high side refrigeration pressure.
It is set to shut the machine off if the discharge
pressure should ever exceed 450 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.

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.

Drain Tube: When uncapped
and lowered, drains the
evaporator.

ICE LEVEL SENSORS

WATER LEVEL

SENSOR

EVAPORATOR

Condenser: Air or water

cooled, where the heat
removed in ice making is
discharged.

Ice Storage Bin Assembly: A
plastic lined, insulated cylinder
that receives, stores and
dispenses the ice. Fresh ice
enters at the top, and when the
bin is full enough the ice will be
between the ice level sensors,
and the ice making will stop.
Ice is dispensed through a
chute at the bottom front when
the bin vane sweeps the ice
over the chute.

RESERVOIR

DRAIN TUBE

HIGH PRESSURE

CUT OUT

ICE STORAGE BIN

CONDENSER

TOUCH FREE SENSOR

Page 10

COMPONENT DESCRIPTION

GEMD520-GEMD525-GEMD540

Evaporator: A refrigerated vertical tube filled with

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: 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 split phase motor that drives the gear
reducer.

Thrust 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

BEARING

BREAKER

EVAPORATOR

AUGER

WATER SEAL

MOTOR

Page 11

GEMD520-GEMD525-GEMD540

COMPONENT DESCRIPTION: Control Box

Circuit Board:

The circuit board receives
input signals from several
sensors and translates them to
control the electrical power
supply to the various loads.

The sensors include:

Touch Free ice or water.

·

Ice level in the bin.

·

Water level in the reservoir.

·

The loads include:

Compressor contactor

·

Fan motor

·

Bin drive motor

·

Auger drive motor

·

Water solenoid.

·

In addition, a “Clean” switch is
available to temporarily disable
the Touch-Free sensors for
cleaning of the splash panel.

ON-OFF
SWITCH

START

CAPACITOR

CONTACTOR

POTENTIAL

RELAY

On/Off Switch: Manual

control for the machine.

Contactor: A definite purpose
contactor connecting the
compressor to the power
supply.

Potential Relay: The
compressor start relay.

CIRCUIT

BOARD

Page 12

GEMD520-GEMD525-GEMD540

ELECTRICAL SEQUENCE

Refer the wiring diagram as needed.

The “Power” light on the board glows whenever
there is power to the machine (and the master
switch is ON).

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:

After a 6 minute delay, 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.

The bin empty and power lights on the circuit

·

board glow.

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 contactor coil receives power

·

from the circuit board.

The contactor is energized, connecting power to

·

the compressor, and the compressor starts.

The auger motor receives power from the circuit

·

board and 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.

Other reasons for shut down:

·

Low water level (as sensed by the thermistor in
the reservoir).

Shut Down consists of:

·

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 no longer receives power from
the circuit board, and the auger motor stops.

When the water level in the reservoir falls

·

below the tip of the water level sensor, the
machine will “shut down”

After a 6 minute delay, if the water refills the

·

reservoir, the machine will start up again.

Separate from the circuit board:

If the high pressure control (cut out switch)

·

opens, the compressor will stop immediately
(through the contactor ). It must be manually
reset.

The master switch is the manual control for the

·

complete machine, but it is not a service
disconnect.

Ice Vending

When a user places a container in front of the

·

Touch Free ice sensor and below the ice
delivery chute, the circuit board connects power
to the bin drive motor and ice is dispensed for
as long as the container is present. If the user
does not remove the container, ice will be
dispensed for 60 seconds and then stop.

·

When a user places a container in front of the
Touch Free water sensor, and below the water
spout, the circuit board connects power to the
water solenoid valve and water is dispensed. If
the user does not remove the container water
will be dispensed for 90 seconds and then stop.

Splash panel cleaning:

·

A switch, located next to the water spout, may
be pushed to disable the Touch-Free sensors
for splash panel cleaning. It automatically resets
after 2 minutes, or, if pushed within the 2
minutes, resets the circuit board to enable the
Touch Free sensors.

Splash Panel

Cleaning or
Touch Free

Disable Switch

Page 13

GEMD520-GEMD525-GEMD540

OPERATION: Water

Water enters the machine through the 3/8" male
flare at the rear of the cabinet, goes to a strainer
and then 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, evaporator condensation and
water in the sink are all 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 down the drain.

There is also an additional water circuit to an
electric valve. When the Touch Free system
senses a container for water, it closes a circuit to
the electric water valve, and water is dispensed.

Note: The correct water level is determined when

the machine is operating. Check the water level and

compare it to the line molded into the side of the

reservoir. The water level should be between

If needed, adjust the water level by bending the

above and

1

" below the line.

4

float arm.

1

“

8

WATER RESERVOIR

WATER INLET

WATER DRAIN

WATER

LEVEL

WATER LINE FOR

WATER STATION

Page 14

OPERATION: Refrigeration

GEMD520-GEMD525-GEMD540

Beginning at the compressor, the refrigerant 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

SCHEMATIC

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

LIQUID LINE

CONDENSER

DISCHARGE

LINE

COMPRESSOR

EVAPORATOR

THERMOSTATIC

EXPANSION VALVE

Page 15

GEMD520-GEMD525-GEMD540

OPERATION: Ice Vending

Dispensing takes place when the
Touch Free sensor’s infrared beam
bounces back to the sensor from a
container placed directly in front of
it.

If the container is in front of the
Touch Free sensor on the left side,
the ice dispensing vane will rotate
and sweep ice over the ice
dispensing chute: ice will continue
to discharge out this chute as long
as the vane is turning. It stops
when the dispensing vane stops.

If the container is in front of the
Touch Free sensor on the right
side, the inlet water valve will open
and water will flow into the
container.

ICE CHUTE

ICE DISPENSING

VANE

BIN BOTTOM

TOUCH FREE

SENSOR

DRIVE

MOTOR

TOUCH FREE

SENSOR

SINK

The Touch Free System:

Hold or Place a Container in Front

of The Touch Free Sensor & Under

The Ice or Water Spout;

Ice or Water Will Be Dispensed

Without Touching The Dispenser

Page 16

GEMD520-GEMD525-GEMD540

DISPENSE AREA SANITATION

The dispense area; spouts, sink, grill and splash
panel will need periodic cleaning and maintenance.

1. The ice chute may be pulled down to remove it
from the ice dispenser. Wash and sanitize it.

2. The sink grill may be removed for washing and
sanitizing.

3. The sink should be flushed with hot water and
wiped clean with sanitizer.

4. The splash panel requires special attention to
clean it.

Push and release the Splash Panel Cleaning

·

switch located to the left of the water spout.
This disables the Touch Free sensors so the
splash panel may be cleaned without vending
ice and/or water.

Wash the splash panel and wipe with with

·

sanitizer.

Re-push the clean switch or allow 2 minutes to

·

pass for the Touch Free system to reset.

Page 17

Splash Panel

Cleaning or Touch

Free Disable Switch

Push and Release

GEMD520-GEMD525-GEMD540

CLEANING and SANITIZING

An Ice-O-Matic ice machine 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.

Sanitizing of the ice storage bin should be scheduled for a minimum of 4 times a year.

Electrical power will be ON when doing in place
cleaning.

ICEMAKING SYSTEM: In place cleaning

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

2. Remove screws and remove the upper front
panel.

3. Move the ON-OFF switch to OFF.

4. Remove the cover to the ice storage bin, and
remove the ice.

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.

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

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.

To Sanitize:

Repeat steps 8-11, only use an approved sanitizing
solution in place of the cleaning solution. A
possible sanitizing solution to use could be 1
ounce of household bleach mixed with 2 gallons of
warm (95

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.

o

F.-115oF.) water.

Ice Machine Cleaner

contains acids.

These compounds may
cause burns. If swallowed,
DO NOT induce vomiting.
Give large amounts of
waterormilk.Call
Physician immediately. In
case of external contact,
flush with water. Keep out
of the reach of children.

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

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 cover, dispensing vane, bin
bottom, and interior with an approved sanitizer
using the directions for that sanitizer.

18. Replace the ice storage bin cover, and the front
panel.

Page 18

GEMD520-GEMD525-GEMD540

MAINTENANCE AND CLEANING

Moving Parts Hazard.

Disconnect electrical
power to the icemaker ­dispenser before
beginning.

1. Air Cooled Models: Check the air cooled
condenser for lint, dirt or grease build-up. Clean
with vacuum or soft brush until light can be seen
thru the fins.

BIN CONTROL

SENSOR

BIN CONTROL

SENSOR

Slide UP To

Remove

Reservoir

CLEAN WATER

SENSOR PROBE

CAUTION

THE TIP IS

MADE OF GLASS

BIN TOP

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.

3. 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 grommets in the ice
chute, and wipe them clean.

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

A. Check the bearing by:

Inspect the assembly, looking for wear.

ICE SWEEP

·

removing the ice chute cover

·

unscrewing the ice sweep

·

removing the water shed

·

unscrewing the breaker cover.

·

unscrewing the auger stud

See Removal and Replacement to replace
bearing or seals. Reverse to reassemble.

5. Check and tighten all bolts and screws.

Page 19

GEMD520-GEMD525-GEMD540

MAINTENANCE AND CLEANING

In some areas, the water supply to the ice maker
will contain a high concentration of minerals, 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.

Moving Parts Hazard.

Disconnect electrical
power to the icemaker ­dispenser before
beginning.

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 the front and top
panels.

2. Push bail clamp off of cover and remove cover.

3. Unscrew and remove ice sweep.

4. 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.

ALLEN

HEAD

SCREWS

BREAKER

AND AUGER

ASSEMBLY

Page 20

GEMD520-GEMD525-GEMD540

SERVICE DIAGNOSIS

Symptom Possible Cause Probable Correction

No ice made, nothing operates Unit off due to no power Restore power

Unit off due to master switch in
OFF position

Unit off due to low water level Check water supply, filter,

Unit off due to ice level sensors
(photo-electric eyes) blocked

Unit off due to scale on water level
sensor

Unit off due to water temperature
too high

Unit operates, no ice is vended Check for ice in the bin If no ice, check that ice maker can

Check for jam up of ice in
dispense chute

If there is ice, check that the bin
vane rotates. if not

If there is power to the bin drive
motor, but the vane does not turn

Compressor on, auger motor is off Auger motor windings open Replace auger motor

Auger motor relay does not make Replace circuit board

Contactor stuck Replace contactor

Compressor does not operate Off due to high pressure control

open

Contactor coil is open Replace contactor

Contactor contacts do not make Replace contactor

Start capacitor failed Replace start capacitor

Potential relay failed Replace relay

Compressor windings open Replace compressor

Compressor locked Replace compressor

Switch master switch to ON

strainer, float valve. Correct water
supply

Check/clean ice level sensors

Clean water level sensor

Thermistor will shut down unit at
temperatures over 110

make ice

Check that machine cannot keep
up with needs

Pull chute down and allow ice to
fall out. Return chute to its normal
place.

Check for power to the bin drive
motor, if none, check condition of
Touch-Free ice sensor.

Disconnect electrical power,
remove all ice, check mechanical
condition of ice vane. Replace if
broken.

If ice vane is mechanically sound,
check bin drive, replace if broken.

Check condenser, fan motor, fan
blade, or water supply on water
cooled.

o

F.

Page 21

GEMD520-GEMD525-GEMD540

SERVICE DIAGNOSIS

Symptom Possible Cause Probable Correction

No water is vended Check ice vending system, if no

ice will dispense, check the splash
panel cleaning switch

Check water supply Restore water supply

Check inlet water valve Replace valve if necessary

Makes ice, but with excessive
noise

Will not dispense ice Vane turns & ice is available but

Touch Free ice dispensing system
does not operate water solenoid
or dispense motor

No power to compressor contactor
and auger motor

Mineral scale on auger or
evaporator

Dry top bearing Check top bearing for proper

Dry auger drive gear motor Check auger drive for proper

Auger motor rotor bearings worn Replace auger motor

Vibration from loose panel or
tubing

Low water level Check for air-lock in water line to

will not flow out of bin

Check splash panel cleaning
switch

Check for power to motor or
solenoid

If new touch free sensors do not
fix problem

Power light on, but Bin empty light
not on

Power light not, bin empty light on,
but Low water light on

Electric eyes failed Replace photo electric eyes

Thermistor failed Replace water level sensor

Circuit board failed Replace circuit board

Allow 2 minutes for system to
reset

Clean ice making system with
Scotsman Ice machine cleaner

lubrication

lubrication

Locate vibrating component and
secure it.

evaporator

Check for thermistor (water level
sensor) not shutting unit off when
there is lack of water.

Check position of bin bottom. It
must have its slot over the ice
dispense spout.

Check condition of bin walls. They
must be smooth and the bin must
be round. Replace if rough or out
of round.

Push to reset or wait 2 minutes for
the board to reset itself

If power, check motor or solenoid.
If no power, replace touch free
sensors

Replace circuit board.

Check for ice between electric
eyes or dirty eyes.

Not enough water.

Water too hot

Page 22

GEMD520-GEMD525-GEMD540

SERVICE DIAGNOSIS: Circuit Board

1

2

3

Explanation of Indicator Light Position On

Board

On at all times when the master switch is ON and machine is
connected to electrical power.

On when ice level is low (unit making ice).

Normal 6 minute off/delay start. To prevent short cycling, the
machine will not restart after any shut off (except power to the
board) until 6 minutes have passed.

On when water level is low in the reservoir.

1

2

3

4

4

Name and Meaning of
Light or Reset

Power,
ON = Normal

Bin Empty,
ON = Needs Ice

Off Timer,
ON = Unit cycling off

No Water,
ON = Trouble

Page 23

GEMD520-GEMD525-GEMD540

REMOVAL AND REPLACEMENT

WATER RESERVOIR

1. Shut off the water supply to the icemaker.

2. Remove front panel and reservoir cover.

3. Disconnect inlet water line from valve.

4. To remove just the float, push the locking tab at
the back of the valve mounting block in and lift the
valve and block up and out of the reservoir tank.

Note: inside the valve, there is a plunger which
may be replaced separately, if desired.

5. To remove reservoir, 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.

BIN CONTROLS (Ice Level Sensors)

1. Disconnect electrical power.

2. Remove front panel.

3. Remove control box cover.

4. Locate bin top, in front of and behind it are two
rubber bin control grommets.

5. Pull each bin control out, 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.

BIN CONTROLS

FLOAT VALVE

VALVE

PLUNGER

LOCKING TAB

GROMMETS

BIN TOP

Page 24

GEMD520-GEMD525-GEMD540

REMOVAL AND REPLACEMENT: Bearing And Breaker

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

Moving Parts Hazard.

Disconnect electrical
power to the icemaker ­dispenser before
beginning.

To Remove the Breaker Bearing Assembly:

1. Remove panels and disconnect electrical power.

2. Move bail clamp back 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 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
Ice-O-Matic part number 6051062-01 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 Ice-O-Matic part
number 6051036-01 to the seal area before
installing on the auger.

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

Steps 3 - 5a

Step 5 b Steps 5c - 6

BEARING

ICE

SWEEP

BREAKER

AUGER

STUD

BREAKER

Page 25

GEMD520-GEMD525-GEMD540

REMOVAL AND REPLACEMENT

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.

Moving Parts Hazard.

Disconnect electrical
power to the icemaker ­dispenser before
beginning.

1. The top panel must be removed.

2. Remove ice chute cover.

3. Unscrew ice sweep.

4. 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.

c. Unscrew 4 allen head cap screws holding
breaker to evaporator.

d. Lift up & 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

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.

BREAKER

AND AUGER

ASSEMBLY

Page 26

GEMD520-GEMD525-GEMD540

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 exposed. (See illustration - next page)

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.

4. Place a small bead of food grade silastic sealant
(such as 732 RTV) 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.

WATER

SEAL

RETAINING

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.

FOOD GRADE

SILASTIC

SEALANT

HERE

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

Page 27

GEMD520-GEMD525-GEMD540

REMOVAL AND REPLACEMENT

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”)
sweat in the new evaporator at the old tubing
connections.

6. Install a 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.

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.

For Access to the Evaporator to
Gearmotor bolts:

1. Remove upper front and top panels.

2. Remove screws holding control box
assembly to the cabinet, move the control
box out of the way, temporarily secure to
cabinet.

3. Remove the upper half of the ice chute.

4. Remove the ice sweep.

5. Loosen clamp under ice chute, and
remove the lower half of the ice chute.

6. Remove the 2 screws securing the
front portion of the gearmotor support to
the cabinet

7. Move the the gearmotor - evaporator to
the right: space is now available for
removal of the evaporator and gearmotor
bolts. When reassembling, reverse the
above steps.

MOVE THE

GEARMOTOR -

EVAPORATOR

CONTROL

BOX

SCREWS

Page 28

GEMD520-GEMD525-GEMD540

TO REMOVE AND REPAIR THE GEARMOTOR ASSEMBLY

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

Electrical Shock
Hazard.

Disconnect electrical
power to the icemaker ­dispenser before
beginning.

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.

GEARCASE

COVER

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.

ROTOR

BEARING

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

FIRST GEAR &

BEARINGS

GASKET

Page 29

GEMD520-GEMD525-GEMD540

REFRIGERATION SERVICE: R-404A (HP62)

THIS ICE MACHINE USES HP62 REFRIGERANT
AND POLYOLESTER COMPRESSOR OIL.

Pressure-Temperature Chart for HP62

DO NOT USE MINERAL OIL IN THIS
REFRIGERATION SYSTEM.

R-404A is a “Near Azeotrope”, and therefore

·

liquid charging is required.

Weigh into the discharge side as much as
possible of the charge as liquid refrigerant.

Install a sight glass between the manifold
and the suction side hose. Carefully meter
liquid refrigerant into the suction side, using
the manifold valve to “flash off” the liquid
before it enters the ice machine. Do this until
the proper charge has been weighed into the
system.

When the system is serviced, a special liquid

·

line dryer is required.

Polyolester oil absorbs water very easily, and

·

therefore when the system is opened for
service, it must be re-sealed as soon as
possible (15 minutes maximum).

Special leak detection equipment is required to

·

locate small refrigerant leaks. Usually a leak
detector capable of detecting a Halogenated
refrigerant or HFC-134A will work. Check with
the leak detector manufacturer if in doubt.

·

As with any other refrigerant, do NOT mix HP62
with pressurized air when leak testing.

VAPOR VAPOR

TEMP. PRESSURE TEMP. PRESSURE

(DEG F) (PSIG) (DEG F) (PSIG)

-20....17 70......146

-18....18 72......150

-16....20 74......155

-14....21 76......161

-12....23 78......166

-10....24 80......171

-8 ....26 82......177

-6 ....28 84......182

-4 ....29 86......188

-2 ....31 88......194

0 ....33 90......200

2 ....35 92......206

4 ....37 94......212

6 ....39 96......219

8 ....41 98......225

10 ....43 100.....232

12 ....46 102.....239

14 ....48 104.....246

16 ....50 106.....253

18 ....53 108.....260

20 ....55 110.....268

22 ....58 112.....275

24 ....60 114.....283

26 ....63 116.....291

28 ....66 118.....299

30 ....69 120.....307

32 ....72 122.....316

34 ....75 124.....324

36 ....78 126.....333

38 ....81 128.....342

40 ....85 130.....351

42 ....88 132.....360

44 ....91 134.....370

46 ....95 136.....379

48 ....99 138.....389

50 ....102 140 .....399

52 ....106 142 .....409

54 ....110 144 .....420

56 ....114 146 .....430

58 ....118 148 .....441

60 ....123 150 .....452

62 ....127 152 .....464

64 ....132 154 .....475

66 ....136 156 .....487

68 ....141 158 .....499

Page 30

REFRIGERATION SERVICE

GEMD520-GEMD525-GEMD540

General Information:

Work on the refrigeration system should only be
done when it is certain that the system needs
repair.

Refrain from checking refrigeration

·

pressures without reason. Visual inspection
of the water system, observation of the ice
formation, amp draw, voltage, and other
techniques will lead to proper diagnosis.
Scotsman also recommends that, at the time of
initial start up, gauges not be used.

If gauges must be used, don’t 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 more
important on an ice machine than the high side.

If gauges must be used, use very short hoses to

·

minimize refrigerant discharged into the air.

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.

· 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. Note:

Only a HFC type dryer should be used.

·

When brazing the tubing connections to
components such as the TXV, the component
must be protected by heat sink material.

Recover, reclaim or recycle refrigerant. The
method chosen is up to the service company. Any
refrigerant placed into a Scotsman ice machine
must meet ARI spec 700-88. Reclaim programs are
available through most refrigerant wholesalers.

Access Valves: To use the access valves:

Remove the cap from the stem, use a 3/16" allen
wrench to check that the valve is CLOSED. The
remove the core cap.

Close the valve and replace the caps when the
job is finished. The valve must be closed and
the caps must be on or the valve will leak.

Allen

Wrench

Torque Stem to

6-8 ft. lb.

Torque Stem Cap to

8-12 ft. lb.

Torque Core

Cap to 7-12

ft. lb.

Access Valves

Note: There are no valve

cores in this valve.

Page 31

GEMD520-GEMD525-GEMD540

CIRCUIT BOARD SERVICE

Printed Circuit Board Handling Precautions

Follow these simple precautions when replacing a
Printed Circuit Board

1. Keep the replacement PC Board in the
anit-static packaging until it is ready to be installed.

2. Be sure that your hands are clean.

3. Just before touching the board, touch the
cabinet of the machine to discharge any possible
build up of static electricity.

4. Handle the original and replacement boards only
by their outer edges.

5. Place the original board in the anti-static
package for return (if in warranty).

LIQUID CHARGING

Instructions for R-404A

In preparation for charging, the low side hose
should have a sight glass, and/or a restrictor
device (such as a “Charge Faster”) installed in it
for metering liquid into the low side of the system.

1. After a thorough evacuation to at least 300
microns, shut off the manifold valves and switch off
the vacuum pump.

2. Place a drum of R-404A onto an electronic
scale.

3. Attach the charging hose to the drum.

4. Open the valve on the drum and purge the
charging hose.

5. Zero out the scale.

6. Shut the low side access valve at the ice
machine.

7. Open the discharge manifold valve full open.

8. Watch the scale, when the correct charge is
shown, shut the manifold valve.

Note: If all of the charge will not “go in” the
discharge side:

9. Shut off the valve on the refrigerant drum.

10. Re-open the manifold valves until all liquid has
flowed out of the hoses.

11. Shut the low side access valve on the ice
machine.

12. Remove hoses from ice machine and replace
all caps.

A. Shut the discharge access valve at the ice

machine.

B. Switch the machine on.

C. Open the low side access valve at the ice

machine.

D. Open the low side manifold valve and
observe the sight glass to be certain that only gas
is flowing into the system.

E. When the proper charge is indicated on the
scale, shut off the manifold valve(s).

Page 32

GEMD520-GEMD525-GEMD540

CONTACTOR

T1

CONTACTOR
T2

COMPRESSOR

R

S

C

POTENTIAL
RELAY

START CAP

1

2

COIL

POTENTIAL
RELAY

2

5

RUN CAP

AUGER DRIVE

MOTOR

1

MOT

FAN

BIN DRIVE

MOT

SOL.

WATER

COIL

DISABLE
SWITCH

HIGH
PRESS.

CONTACTOR

COIL

KEY LOCK
SWITCH
(WHEN REQ`D.)

MASTER
SWITCH

POWER SUPPLY

L1

L2

NTC THERMISTOR

USE COPPER CONDUCTORS ONLY.
THIS UNIT MUST BE GROUNDED.
ALL CONTROLS SHOWN IN NORMAL ICE
MAKING MODE WITH ALL DISPENSING
SYSTEMS IN OPERATION.

TX BIN

RX BIN

TX ICE

TX WATER

RX ICE

RX WATER

P.C. BOARD

AIR COOLED
ONLY

2

4

Schematic Diagram

Page 33

GEMD520-GEMD525-GEMD540

BK

R

WATER
SENSOR
NTC

RX/TX DISABLE
SWITCH

JUNCTION BOX

W

BK

BK

R

Y

Y

BU

BK

O

BU

W

R

BU

BU

O

O

V

V/W

BK

BK

BN

BN

TX
BIN

RX
BIN

START CAP

RUN CAP

FAN

MOT

WATER

SOLENOID

MASTER

SWITCH

CONTACTOR

T2L2

T1

L1

2

1

5

POTENTIAL

RELAY

BIN DRIVE

MOT

SWITCHING

CENTRIFUGAL

AUGUR DRIVE MOTOR

4

2

1

OVERLOAD

INTERNAL

RUN

START

INTERNAL
PROTECTOR

COMPRESSOR

TERMINAL

BOX

R

S

C

MOTOR

START

RUN

CONTROL

HI - PRESSURE

SAFETY

RX
ICE

RX
H2O

TX

ICE

TX
H2O

BK

KEY LOCK
(WHEN REQ`D.)

SWITCH

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

PIN LOCATION DETAIL

A37042-001

SEE NAMEPLATE FOR
SUPPLY VOLTAGE

AND MAX. FUSE SIZE

BN

NO

COM

BU

BU

A

1

3

2

6

5

10

11

12

13

14

15

Wiring Diagram, 115/60/1

Page 34

GEMD520-GEMD525-GEMD540

Wiring Diagram 230/50/1

Page 35