Hussmann MicroSC ISMGG2DA-A User manual

ISMGG2DA-A
Medium Temperature Self Contained
Horizontal Merchandiser
with R-290 Refrigerant
Installation &
Operation Manual
P/N 3110586_A
February 2020
Spanish 3110587
MANUAL- I/O ISMGG2DAA
®
Æ
WARNINGS:
If the information in these instructions are not followed
exactly, a fire or explosion may result, causing property
damage, personal injury or death.
Installation and service must be performed by a qualified
installer or service agency.
READ THE ENTIRE MANUAL BEFORE
INSTALLING OR USING THIS EQUIPMENT.
The unit uses R-290 gas as the refrigerant. R-290 is
flammable and heavier than air. It collects first in low
areas but can be circulated by the fans. If propane gas
is present or even suspected, do not allow untrained
personnel to attempt to find the cause. The propane
gas used in the unit has no odor. The lack of smell does
not indicate a lack of escaped gas. If a leak is detected,
immediately evacuate all persons from the store, and
contact the local fire department to advise them that
a propane leak has occurred. Do not let any persons
back into the store until the qualified service technician
has arrived and that technician advises that it is safe to
return to the store. No open flames, cigarettes or other
possible sources of ignition should be used inside or in
the vicinity of the units.
FAILURETOABIDE BYTHISWARNING COULD
RESULT INAN EXPLOSION, DEATH, INJURY AND
PROPERTY DAMAGE.
IMPORTANT
Keep in store for future reference!

P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 1 800-890-2900 • www.hussmann.com
ii
BEFORE YOU BEGIN
Read these instructions completely and carefully.
PERSONAL PROTECTION EQUIPMENT (PPE)
Personal Protection Equipment (PPE) is required whenever installing or servicing this
equipment. Always wear safety glasses, gloves, protective boots or shoes, long pants, and a
long-sleeve shirt as required when installing or servicing this equipment.
1. If the information in these instructions are not followed exactly, a fire or explosion may result, causing property damage, personal injury
or death.
2. Installation and service must be performed by a qualified installer or service agency.
3. This unit is designed only for use with R-290 gas as the designated refrigerant.
THE REFRIGERANT LOOP IS SEALED. ONLY A QUALIFIED TECHNICIAN SHOULD ATTEMPT TO SERVICE!
• Propane is flammable and heavier than air.
• It collects first in the low areas but can be circulated by the fans.
• If R-290 is present or even suspected, do not allow untrained personnel to attempt to find the cause.
• The propane gas used in the unit has no odor.
• The lack of smell does not indicate a lack of escaped gas.
• If a leak is detected, immediately evacuate all persons from the store, and contact the local fire department to advise them that a
pro pane leak has occurred.
• Do not let any persons back into the store until the qualified service technician has arrived and that technician advises that it is
safe to return to the store.
• A hand-held propane leak detector (“sniffer”) shall be used before any repair and/or maintenance.
• No open flames, cigarettes or other possible sources of ignition should be used inside the building where the units are located
until the qualified service technician and/or local fire department determines that all propane has been cleared from the area and
from the refrigeration systems.
• Component parts are designed for propane and non-incendive and non-sparking. Component parts shall only be replaced with
identical repair parts.
FAILURE TO ABIDE BY THIS WARNING COULD RESULT IN AN EXPLOSION, DEATH, INJURY AND PROPERTY DAMAGE.

P/N 3110586_A iii
ANSI Z535.5 DEFINITIONS ............. vi
INSTALLATION
UL Listing .............................1-1
Federal / State Regulations ................1-1
Hussmann Product Control .............. 1-1
Shipping Damage ...................... 1-1
Location .............................. 1-1
Self Contained Location ................. 1-2
Model Description ..................... 1-3
Unloading ............................ 1-3
Exterior Loading ....................... 1-3
Shipping Skid ......................... 1-3
Merchandiser Leveling .................. 1-6
Serial Plate Location .................... 1-6
Sealing Merchandiser to Floor ............ 1-6
Condensing Unit Access ................. 1-7
Self-Contained Refrigeration Equipment
Start Up Check List .................... 1-9
ELECTRICAL / REFRIGERATION
Merchandiser Electrical Data ............. 2-1
Field Wiring ........................... 2-1
Electrical Connections . . . . . . . . . . . . . . . . . . . 2-1
Electrical Outlet ........................ 2-1
Refrigeration .......................... 2-1
Before Beginning a Service or Repair ....... 2-2
Replacing Refrigeration System Components 2-3
Steps to Recover Refrigerant ............. 2-3
Charging ............................. 2-3
Waste Outlet and Water Seal ............. 2-4
START UP / OPERATION
Controller Operation .................... 3-1
Key Function .......................... 3-2
Further Information .................... 3-2
Connections ........................... 3-3
LED ................................. 3-4
KDE PLUS Buttons .................... 3-5
Setpoint .............................. 3-6
Sensor to Control Configuration............3-7
Controls Adjustments ................... 3-8
Start Up .............................. 3-9
Load Limits ........................... 3-9
Stocking .............................. 3-9
Thermometer .......................... 3-9
MAINTENANCE
Care and Cleaning ...................... 4-1
Cleaning Discharge Honeycomb .......... 4-2
Cleaning Thermometer .................. 4-2
Cleaning Coils ......................... 4-2
Cleaning Evaporation Pan ............... 4-3
Removing Scratches from Bumper ......... 4-3
Equipment Maintenance Checklist ......... 4-4
SERVICE
Replacing Evaporator Fan Motors and Blades 5-1
Replacing Evaporation Fan Motors ....... 5-2
WARRANTY
TABLE OF CONTENTS
IMPORTANT
KEEP IN STORE FOR FUTURE REFERENCE
Quality that sets industry standards!
12999 St. Charles Rock Road • Bridgeton, MO 63044-2483
U.S. & Canada 1-800-922-1919 • Mexico 1-800-890-2900
www.hussmann.com
© 2020 Hussmann Corporation

P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 1 800-890-2900 • www.hussmann.com
iv
REVISION HISTORY
ORIGINAL ISSUE — FEBRUARY 2020
* * * * * * * * * * * * * * * * * * * * * * * * * *
ANSI Z535.5 DEFINITIONS
• DANGER – Indicate[s] a hazardous
situation which, if not avoided, will
result in death or serious injury.
• WARNING –Indicate[s] a hazardous
situation which, if not avoided, could
result in death or serious injury.
• CAUTION –Indicate[s] a hazardous
situation which, if not avoided, could
result in minor or moderate injury.
• NOTICE – Not related to personal injury –
Indicates[s] situations, which if not avoided,
could result in damage to equipment.
Merchandiser must operate for 24 hours
before loading product!
Regularly check merchandiser temperatures.
Do not break the cold chain. Keep products
in freezer before loading into merchandiser.
These merchandisers are designed
for only pre-frozen products.
AT TENTION
Merchandiser must operate for 24 hours
before loading product!
Regularly check merchandiser temperatures.
Do not break the cold chain. Keep products in
cooler before loading into merchandiser.
These merchandisers are designed
for only pre-chilled products.
— LOCK OUT / TAG OUT —
To avoid serious injury or death from electrical
shock, always disconnect the electrical power
at the main disconnect when servicing or
replacing any electrical component. This
includes, but is not limited to, such items as
doors, lights, fans, heaters, and thermostats.
Case ventilation openings must be clear of any
obstructions. Do not damage the refrigerant
circuit.
Do not use mechanical devices or other means
to accelerate the defrosting process.
Do not use electrical appliances inside the food
storage compartments of the case.
All installation and operating instructions
concerning the handling, moving, and use of
these merchandisers must be carefully followed
to avoid either damaging the refrigerant tubing,
or increasing the risk of a leak.

P/N 3110586_A 1-1
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. ISMGG2DAA Merchandisers
UL LISTING
These merchandisers are manufactured to meet
ANSI/ UL 471 standard requirements for safety.
Proper installation is required to maintain the
listing.
FEDERAL / STATE REGULATION
These merchandisers at the time they are man-
ufactured, meet all federal and state/ provincial
regulations. Proper installation is required to
ensure these standards are maintained. Near
the serial plate, each merchandiser carries a
label identifying the environment for which the
merchandiser was designed for use.
ANSI/NSF-7 Type I – Display Refrigerator /
Freezer
Intended for 75°F (24°C) / 55%RH Ambient Application
ANSI/NSF-7 Type II – Display Refrigerator / Freezer
Intended for 80°F / 55%RH Ambient Application
ANSI/NSF-7 – Display Refrigerator
Intended for Bulk Produce
HUSSMANN PRODUCT CONTROL
The serial number and shipping date of all
equipment is recorded in Hussmann’s files
for warranty and replacement part purposes.
All correspondence pertaining to warranty or
parts ordering must include the serial number
of each piece of equipment involved. This is to
ensure the customer is provided with the cor-
rect parts.
SHIPPING DAMAGE
All equipment should be thoroughly examined
for shipping damage before and during
unloading. This equipment has been carefully
inspected at our factory. Any claim for loss
or damage must be made to the carrier. The
carrier will provide any necessary inspection
reports and/or claim forms.
Apparent Loss or Damage
If there is an obvious loss or damage, it must
be noted on the freight bill or express receipt
and signed by the carrier’s agent; otherwise,
carrier may refuse claim.
Concealed Loss or Damage
When loss or damage is not apparent until
after equipment is uncrated, retain all packing
materials and submit a written response to the
carrier for inspection within 15 days.
LOCATION
These merchandisers are designed for
displaying products in air conditioned stores
where temperature is maintained at or below
the ANSI / NSF-7 specified level and relative
humidity is maintained at or below 55%.
Placing refrigerated merchandisers in direct
sunlight, near hot tables or near other heat
sources could impair their efficiency. Like
other merchandisers, these merchandisers are
sensitive to air disturbances. Air currents
passing around merchandisers will seriously
impair their operation.
DO NOT allow air conditioning, electric fans,
open doors or windows, etc. to create air cur-
rents around the merchandiser.
INSTALLATION
Recommended operating ambient
temperature is between
65°F (18°C) to 75°F (23.9°C).
Maximum relative humidity is 55%.

1-2 INSTALLATION
P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
SELF CONTAINED LOCATION
Product should always be maintained at proper
temperature. This means that from the time
the product is received, through storage, prepa-
ration and display, the temperature of the
product must be controlled to maximize the
life of the product.
Self Contained models have vented base panels
to allow air circulation through the condensing
unit.
See illustrations for clearances distances from
walls, merchandisers, and any other large
objects near the merchandiser’s vented base
panels. Blocking or restricting air flow will
adversely affect performance and may damage
the refrigeration system.
These models need clearance a minimum of 1
inch on each side and at the back of the unit.
UPPER ISLAND
LOWER ISLAND
AIR INTAKE AIR EXHAUST
1.3
This warning does not mean that Hussmann products
will cause cancer or reproductive harm, or is in
violation of any product-safety standards or
requirements. As clarified by the California State
government, Proposition 65 can be considered more of
a‘right to know’ law than a pure product safetylaw.
When used as designed, Hussmann believes that our
products are notharmful. We provide the Proposition
65 warning to stay in compliance with California State
law. It is your responsibility to provide accurate
Proposition 65 warning labels to your customers when
necessary. For more information on Proposition 65,
please visit the California State government website.
August 31, 2018
Top View
Side View
Air intake
through
bottom grille
Air intake
through
side grille
FRONT VIEW
Keep discharge and intake areas free
from air currents.
Air exhaust near
bottom grille
4-inch Clearance
Air
intake
Air
exhaust
Lower Island
Upper Island

P/N 3110586_A 1-3
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. ISMGG2DAA Merchandisers
MODEL DESCRIPTION
ISMGG2DAA merchandisers offer versatility
for the display of food items such as: fresh
fruit, vegetables, cheeses and other delicatessen
items. Carefully read and follow the instruc-
tions prior to operating the merchandiser.
UNLOADING
Unloading from Trailer:
Lever Bar (also known as a Mule, Johnson
Bar, J-bar, Lever Dolly, or Pry Lever)
Move the merchandiser as close as possible to
its permanent location and remove all packaging.
Check for damage before discarding packaging.
Remove all separately packed accessories such
as kits and shelves.
Improper handling may cause damage to the
merchandiser when unloading. To avoid damage:
1. Do not drag the merchandiser out of the
trailer. Use a Johnson bar (mule).
2. Use a forklift or dolly to remove the
merchandiser from the trailer.
EXTERIOR LOADING
Do NOT walk on top of merchandisers or
damage to the merchandisers and serious
personal injury could occur. Do not stand
inside of merchandiser
SHIPPING SKID / CRATE
Each merchandiser is shipped on a skid to
protect the merchandiser’s base, and to make
positioning the case easier.
Do not remove the shipping skid until the
merchandiser is near its final location. The
skid provides protection for both the merchan-
diser and the floor.
DO NOT TILT MERCHANDISER ON ITS
SIDE OR END WHEN REMOVING SKID.
Once the skid is removed, the merchandiser
must be lifted —NOT PUSHED— to reposition.
Check floor where merchandisers are to be set
to see if it is a level area. Determine the highest
part of the floor.
To remove the shipping crate do the following:
Do NOT remove shipping crate until the
merchandiser is positioned for installation.
Do NOT stand or walk on top of
merchandiser. Do not store items or
ammable materials atop the unit.

1-4 INSTALLATION
P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
2. Use a cordless screwdriver to remove the
screws attached at the sides, front and rear of
the crate.
3. Remove the protector plastic bag, which
is covering the case. Carefully remove the
strapping wrapped around the case. Remove
white protectors around the case (10 pieces).
4. Remove the frontal screws from the skid-
crate brackets. (4 brackets total).
5. Identify the taller case. Remove the case
from the skid with a fork lift. Set the forks
below the taller case base, between rail base
and wood skid. Maximum fork opening is
29 ½ inches in order to avoid damaging the
casters.
Taller
Case
Forklift
Direction
Frontal
Screws
Brackets

P/N 3110586_A 1-5
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. ISMGG2DAA Merchandisers
The power cord is located below the frontal
baffle, taller case, attached with cable ties.
6. Lift case with forklift, and remove the
screws from the shipping braces (both sides
of the case) in order to set the case to its final
location.
Power
Cord
Maximum Forklift Opening is 29 ½ inches
Shipping
Braces

1-6 INSTALLATION
P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
MERCHANDISER LEVELING
Besure to position merchandisers
properly. Level the merchandiser by all four
corners. Merchandiser(s) must be installed
level to ensure proper operation of the
refrigeration system, and to ensure proper
drainage of defrost water.
SERIAL PLATE LOCATION
The serial plate is located on the inside of the
merchandiser’s display area near the return air.
NOTE:
Impacts from shopping carts can cause wood to wear,
cracks, chipping or peeling. To avoid these impacts, it
is required to install a floor bumper (or alike) around
the case or other type of protection to prevent damage
to the wood.
SEALING MERCHANDISER TO FLOOR
If required by local sanitary codes, or if the
customer desires, merchandisers may be sealed
to the floor using a vinyl cove base trim.
The size needed will depend on how much
variation there is in the floor, from one end of
the merchandiser to the other. Sealing of the
lower front and rear panels on self contained
models may hamper their removal for servicing
or maintenance of the condensing unit.
NOTE:
Do not allow trim to cover any intake or discharge
grilles located in the lower front panel.
Serial Plate

P/N 3110586_A 1-7
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. ISMGG2DAA Merchandisers
CONDENSING UNIT ACCESS
WOOD PANEL FRONT
CORNER HIGH SIDE RH
CORNER LOW SIDE LH
WOOD PANEL END LH
CORNER HIGH SIDE LH
To access the condensing unit and electrical box, it is necessary remove the wood panel front and wood
panel end (LH).
To do this:
1. Using a screwdriver or cordless drill, remove all the screws from Corner High Side LH.
2. Remove screws from corner low side (LH), only the ones attached to wood panel end (LH).
3. Carefully pull the Wood Panel End LH to the right.
GDF 3.0 SHEET SIZE D
NOTES:
1. APPLICABLE STANDARDS / SPECIFICATIONS
ASME Y14.5M-1994, DIMENSIONS AND TOLERANCES
2. KEY PRODUCT CHARACTERISTICS PER EPR-0006 & IDENTIFIED WITH SYMBOL
3. MATERIAL-
4. REF -
K
SHEET 3 OF 6
P/N REV
THIRD
ANGLE
PROJECTION
UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN INCHES.
R
PULL WOOD PANEL
END TO THE RIGHT
Pull Wood Front Panel
to the Right
CORNER LOWER SIDE LH
WOOD PANEL END LH
CORNER HIGH SIDE RH
WOOD PANEL FRONT
CORNER HIGH SIDE LH

1-8 INSTALLATION
P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
Remove screws from corner high side (RH), only the ones attached to wood panel front.
4. Carefully pull the wood panel front to the le.
5. Remove screws on the condensing unit bae. Remove the bae to access the condensing unit.
Pull Wood Front Panel
to the Left
Condensing Unit
Condensing Unit Baffle
Elecrical Control Box
Pull Wood Front Panel
to the Left
Condensing Unit
Condensing Unit Baffle
Electrical Control Box

P/N 3110586_A 1-9
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. ISMGG2DAA Merchandisers
Hussmann Self-Contained Refrigeration Equipment Start Up Check List
***Please note that failure to follow this start-up document may void your factory warranty***
Form HSCW01 Rev. 30MAY12 P/N 0525209_B
Step Startup Activity Check
1 Locate, read and maintain install/operation manual in a safe place for
future reference.
2 Examine unit. Confirm there is NO damage or concealed damage.
3 Level the unit, side to side and front to rear.
4 Remove all shipping brackets/compressor straps/bolts etc.
5 Unit must be run on a dedicated electrical circuit without the use of
an extension cord.
6 Ensure that the proper electrical requirements for the equipment are
supplied.
7 Verify field electrical connections are tight.
8 Verify all electrical wiring is secured and clear of any sharp edges or
hot lines.
9 Verify the condensate drain line is properly trapped and pitched.
10 Verify all required clearances on the sides and back of unit.
11 Verify there are no air disturbances external to the unit. Heat and air
registers, fans, and doors etc.
Advise owner/operator that merchandiser must operate at temperature for 24 hrs prior to loading
with product.
LEGAL DISCLAIMER:
Hussmann shall not be liable for any repair or replacements made without the written consent of Hussmann, or when the product is installed or operated in a manner
contrary to the printed instructions covering installation and service which accompanied such product.

1-10 INSTALLATION
P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
NOTES:

P/N 3110586_A 2-1
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. ISMGG2DAA Merchandisers
MERCHANDISER ELECTRICAL DATA
Refer to Appendix A of this manual or the
merchandiser’s serial plate for electrical
information.
FIELD WIRING
Field wiring must be sized for component
amperes stamped on the serial plate. Actual
ampere draw may be less than specified.
ELECTRICAL CONNECTIONS
All wiring must be in compliance with NEC
and local codes. All electrical connections (for
remote models) are to be made in the electrical
Handy Box located behind the removable base
panel at the left end of the merchandiser when
facing the discharge air louver.
ELECTRICAL OUTLET
Before the merchandiser is connected to any
wall circuit, use a voltmeter to check that the
outlet is at 100% of the rated voltage. The wall
circuit must be dedicated for the merchandiser.
Failure to do so voids the warranty. Do not
use an extension cord. Never plug in more
than one merchandiser per electrical circuit.
• Always use a dedicated circuit with the
amperage stated on the unit.
• Plug into an outlet designed for the plug.
• Do not overload the circuit
• Do not use long or thin extension cords.
Never use adapters.
• If in doubt, call an electrician.
Self-contained models have factory-installed
power cords attached at the electrical box.
REFRIGERATION
Each self contained model is equipped with
its own condensing unit and control panel
located beneath the display area. The
merchandiser refrigeration piping is leak
tested. The unit is charged with refrigerant
and shipped from the factory with all service
valves open. All models have a hermetic com-
pressor. The systems employ capillary tubes
for refrigerant flow control.
ELECTRICAL / REFRIGERATION
ALWAYS CHECK THE SERIAL PLATE FOR
COMPONENT AMPERES
Risk of Electric Shock. If cord or plug
becomes damaged, replace only with
a cord and plug of the same type.
Merchandiser must be grounded.
Do not remove the power supply cord ground.
NEMA 5-15P
Electrical Plug

2-2 ELECTRICAL / REFRIGERATION
P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
Before Beginning Any Service or Repair:
Use a hand-held propane leak detector (“sniffer”)
to ensure no propane is present in the immediate
area, the inside of the display case and the inside
of the refrigeration system. R-290 is an odorless
refrigerant. Keep the area clear of all customers
and non-essential or unauthorized personnel.
Verify that all repair parts are identical models
to the ones they are replacing. Do not substitute
parts such as motors, switches, relays, heaters,
compressors, power supplies or solenoids.
Failure to do so can result in an explosion,
death, injury and property damage. Parts
used on hydrocarbon cases must meet specic
UL certication for non-incendive or non-
sparking components. Use only Hussmann
approved parts approved through the Hussmann
Performance Parts Website. https://parts.
hussmann.com/
Brazing must not begin before all propane has
been cleared from the immediate area — the
inside of the displays case and the inside of the
refrigeration system.
Only Hussmann or factory
trained technicians should
service or repair this R-290
(propane) equipment.
Failure to follow
instructions can result in
an explosion, death, injury
and property damage.
If a leak is detected, follow store safety
procedures. It is the store’s responsibility to have
a written safety procedure in place. The safety
procedure must comply with all applicable codes
such as local re department’s codes.
At minimum, the following actions are required:
• Immediately evacuate all persons from the
store, and contact the local re department to
advise them that a propane leak has occurred.
• Call Hussmann and/or a qualied service
agent and inform them that a propane sensor has
detected the presence of propane.
• Do not let any persons back into the store
until the qualied service technician has arrived
and that technician advises that it is safe to
return to the store.
• The propane gas used in the unit has no odor.
The lack of smell does not indicate a lack of
escaped gas.
• A hand-held propane leak detector
(“sniffer”) should be used before any repair and/
or maintenance is attempted. All repair parts
must be identical models to the ones they are
replacing.
• No open flames, cigarettes or other possible
sources of ignition should be used inside the
building where the units are located until the
qualied service technician and/or local re
department determines that all propane has been
cleared from the area and from the refrigeration
systems.

P/N 3110586_A 2-3
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. ISMGG2DAA Merchandisers
REPLACING REFRIGERATION SYSTEM
COMPONENTS
STEPS TO RECOVER REFRIGERANT
1. Make sure you are in a well ventilated area be-
fore making any service or repair to the refriger-
ation system.
2. Disconnect all power sources from the system.
Some systems may have more than one plug or
power supply.
3. Tap system with line tap valves, attaching gauges to
the high and low sides of the system.
4. Connect hose to an evacuated recovery tank.
Open refrigeration gauges and recovery tank.
5. With the suction valve in vacuum, the refrigerant will
be recovered into the recovery tank.
6. Once recovered, close the tank valve and remove
the guage from the tank and connect nitrogen tank
to the system to purge it with nitrogen.
7. Pull vacuum to a minimum of 200 microns or
lower.
CHARGING
A calibrated scale with +/-2 gram accuracy
must be used to charge the system. The charge
amount is shown on the serial plate. Only R-290
grade refrigerant can be used. Standard propane
does not meet the purity/moisture content of
R-290, and therefore cannot be used to charge
cases.
No gas charge adjustments are allowed. When
connecting hoses between the refrigeration
system, manifold gauges, and refrigerant
cylinder, ensure that the connections are secure
and there are no potential sources of ignition
nearby. Ensure that contamination of different
refrigerants does not occur when using charging
equipment.
Only Hussmann service technicians or
technicians qualied to handle R-290
(propane) refrigerant should service or
repair this R-290 (propane) equipment
Failure to follow instructions can result
in an explosion, death, injury and
property damage.
refrigeration
line tapping
valve
— LOCK OUT / TAG OUT —
To avoid serious injury or death from electri-
cal shock, always disconnect the electrical
power at the main disconnect when servicing
or replacing any electrical component. This
includes, but is not limited to, such items as
doors, lights, fans, heaters, and thermostats.

2-4 ELECTRICAL / REFRIGERATION
P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
Use dedicated hoses to service R-290 (propane)
refrigeration systems. Hoses or lines should be
as short as possible to minimize the amount of
refrigerant contained in them.
Ensure that the refrigeration system is properly
grounded prior to charging the system with
refrigerant, to avoid the potential for static
build-up.
Extreme care must be taken not to overll the
refrigeration system. After charging, carefully
disconnect the hoses, attempting to minimize
the quantity of refrigerant released. Further
leak check the service ports, hoses, refrigerant
tanks. The service ports shall be checked for
leaks using a hydrocarbon leak detector with a
sensitivity of 3 grams/year (0.106 Oz/year) leak
rate.
Thoroughly leak check the service ports. If no
leak is present, use a pinch-off tool to close the
ends of the service tubes before brazing them
shut. Remove all service ports. If a Schrader
valve is used on the compressor service tube,
it must be removed and the previous steps
followed in order to braze the service tube shut.
WATER OUTLET AND WATER SEAL
The condensate water outlet is located in the
center of the merchandiser. The outlet has a
factory installed, external water seal.
For self contained models, this water seal
drains into the condensate evaporator pan
located beneath the merchandiser. Ensure the
drain hose is properly trapped, and the drain area
is not clogged.
NOTE: All lower base panels must be in place
when the refrigerator is operating. If not, air-
flow from the condenser will be directed over
the evaporator pan and defrost water in the
pan may overflow.
Refrigeration lines are under pressure.
Refrigerant must be recovered before
attempting any connection or repair.
Component parts shall be replaced with like
components, and servicing shall be done by
factory authorized service personnel only, so
as to minimize the risk of possible ignition
due to incorrect parts or improper service.

P/N 3110586_A 3-1
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. ISMGG2DAA Merchandisers
CONTROLLER OPERATION
The electronic controller is located in the
cassette compartment. The controller comes
factory set, and is ready for use. The front grille
must be removed in order to access this control.
When removing the grille for this operation or
for condenser cleaning, care must be taken not
to damage the display interface cable. It may be
unplugged during this task.
1. Before inserting the power cord into a
dedicated receptacle, complete the start-up
sheet on page 1-7. Turn the power switch
to the “off” position. The power switch is
located just below the controller. Next, plug
in the power cord and turn the power switch
“on”. There is a 1-minute power-up delay.
a) The controller will illuminate
b) Interior lighting will illuminate
c) Evaporator fans will start
2. The compressor cut-off is the setpoint
and cut-in is the differential. The setpoint
(cut-out) for the IMGG20DA is 23°F. The
differential (cut-in) is 20°F. A complete
list of setpoints can found on a separate
document that shipped with the case. The
document number is: P/N 3056058.
a.The setpoint is the adjustable
pre-programmed temperature.
b. The differential is the non-adjustable
pre-programmed temperature.
c. The control is designed to read and display
a cabinet temperature not a product
temperature.
Controller Display / Main Switch Access
Use a screwdriver or cordless drill to remove the
screws on the end grille. The controller display
and main switch are on the right side.
ControllerController
DisplayDisplay
End GrilleEnd Grille
MainMain
SwitchSwitch
3. e case is pre-programmed to achieve average
shelf temperature of 38°F (recommended)
for cut fruit and deli sandwiches. (Controller
setpoint is 23°F). If it is needed to change the set
point temperature, follow these steps:
a. To display the set point value, press “SET”
to enter the “Machine status” Menu, then press
“SET” again when the label is displayed.
b. e setpoint value appears on the display.
c. Change the setpoint value to the desired
temperature.
d. Press “SET” again to select the change.
4. e average shelf temperature of 30°F is
recommended for meat (controller setpoint is
16.5°F).
START UP / OPERATION

3-2 STARTUP / OPERATION
P/N 3110586_A U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
Key Functions:
• Evaporator fans and condenser fans
• Frame Heater
• LINK2 local area network
• RS485 communication protocol: Modbus
• Compatible with Device Manager (DM)
• Compatible with Unicard and Multi-function key
2 - SPECIFICATIONS
TECHNICAL DATA
Classification: electronic automatic control (not safety) device for incorporation
Mounting: panel mounting
Type of action: 1.B
Pollution class: 2
Material class: IIIa
Overvoltage category: II
Nominal pulse voltage: 2500V
Temperature: Use: –5 … +55°C - Storage: -30 … +85°C
Power supply: SMPS 100-240Va ±10% 50/60 Hz
Power consumption: 5.5W max
Fire resistance category: D
Software class: A
RTC battery life: In absence of external power, the clock battery will last 3 years.
FURTHER INFORMATION
INPUT CHARACTERISTICS
Measurement range:
Accuracy:
Resolution:
Buzzer:
NTC: -50.0°C ... +110°C; (on 3-digit display with +/- sign)
±1.0° for temperatures below -30°C
±0.5° for temperatures between -30°C and +25°C
±1.0° for temperatures above +25°C
1 or 0.1°C
NO
2 - SPECIFICATIONS
TECHNICAL DATA
Classification: electronic automatic control (not safety) device for incorporation
Mounting: panel mounting
Type of action: 1.B
Pollution class: 2
Material class: IIIa
Overvoltage category: II
Nominal pulse voltage: 2500V
Temperature: Use: –5 … +55°C - Storage: -30 … +85°C
Power supply: SMPS 100-240Va ±10% 50/60 Hz
Power consumption: 5.5W max
Fire resistance category: D
Software class: A
RTC battery life: In absence of external power, the clock battery will last 3 years.
FURTHER INFORMATION
INPUT CHARACTERISTICS
Measurement range:
Accuracy:
Resolution:
Buzzer:
NTC: -50.0°C ... +110°C; (on 3-digit display with +/- sign)
±1.0° for temperatures below -30°C
±0.5° for temperatures between -30°C and +25°C
±1.0° for temperatures above +25°C
1 or 0.1°C
NO