Hussmann microSC MDN4775B1A User manual

MDN (120V)
Medium Temperature Self Contained
Open Vertical Merchandiser
with R-290 Refrigerant
Installation &
Operation Manual
P/N 9FQ6P11007900_B
June 2023
Spanish P/N 9FQ6P11008200
®
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 BYTHIS WARNING COULD
RESULT IN AN EXPLOSION, DEATH, INJURYAND
PROPERTY DAMAGE.
IMPORTANT
Keep in store for future reference!
MANUAL I/O- MDN R-290 120V

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 TOABIDE BY THIS WARNING COULD RESULT IN AN EXPLOSION, DEATH, INJURY AND PROPERTY DAMAGE.
P/N 9FQ6P11007900_B iii

P/N 9FQ6P11007900_B v
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. Open Vertical Merchandisers
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.

TABLE OF CONTENTS iv
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
© 2023 Hussmann Corporation
ANSI Z535.5 DEFINITIONS .............. v
INSTALLATION
UL Listing .............................1-1
Federal / State Regulation ................1-1
Hussmann Product Control ...............1-1
Shipping Damage .......................1-1
Apparent Loss Or Damage ...................1-1
Concealed Loss Or Damage ...................1-1
Location ...............................1-1
Part Names ............................1-3
Additional Parts ........................1-4
Model Description ......................1-5
Unloading .............................1-5
Unloading from Trailer ...........................1-5
Serial Plate Location .....................1-5
Exterior Loading ........................1-5
Shipping Skid ..........................1-5
Thermometer ...........................1-5
Equipment Start Up Check List ............1-6
ELECTRICAL / REFRIGERATION
Merchandiser Electrical Data ..............2-1
Field Wiring ............................2-1
Electrical Connections . . . . . . . . . . . . . . . . . . . . 2-1
Electrical Outlet .........................2-1
Power Switch ...........................2-1
Refrigeration (Self Contained Models) ......2-2
Water Outlet and Water Seal ..............2-2
Controls and Adjustments .................2-3
Controller Operation .....................2-4
Controller Connections ...................2-5
Controller Buttons ......................2-6
Setpoint................................2-7
Defrost Sensor Location ..................2-8
Discharge Air Sensor Location .............2-8
Shelves ................................2-9
Stocking ...............................2-9
Drain Water ............................2-9
Re-Start................................2-9
Service Safety ..........................2-10
Replacing Refrigeration System
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
Steps to Recover Refrigerant .............2-11
Charging .............................2-11
MAINTENANCE
Care and Cleaning .......................3-1
Exterior Surfaces ..........................3-1
Interior Surfaces ..........................3-1
Do NOT Use ...........................3-1
Do Use ................................3-1
Removing Scratches from Bumper ..........3-1
Warnings...............................3-2
Cleaning Steel Surfaces ...................3-4
Cleaning Condenser Coils .................3-4
Cleaning Honeycomb.....................3-5
Cleaning Power Plug .....................3-6
Cleaning Drain Evaporation System ........3-6
Changing Moisture Wicking Plates .........3-6
Night Curtain ..........................3-8
SERVICE
“In Case of the Following” ................4-1
LED Power Supply Location ..............4-1
Troubleshooting ........................4-2
Direct Drain ...........................4-3
Replacement Parts List ...................4-7
WARRANTY

P/N 9FQ6P11007900_B vii
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. Open Vertical Merchandisers
REVISION HISTORY
REVISION B
Updated California Warning and ANSI/NSF References
ORIGINAL ISSUE — NOVEMBER 2021
Excessive ambient conditions may cause
condensation and therefore sweating of doors.
Facility operators should monitor doors and floor
conditions to ensure safety of persons.
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.
Case ventilation openings must be clear of any
obstructions. Do not damage the refrigerant
circuit.
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 fans, heaters, thermostats
and lights.
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.
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.
!
The safety of our customers and employees is
paramount. The precautions and procedures
described in this manual are intended as general
methods for safe use of this equipment. Please
be sure to comply with the precautions described
in this manual to protect you and others from
possible harm, and follow OSHA standards for
safety.
The definitions at right are used to clarify the
magnitude and urgency of harm and damage,
considering problems arising from misuse.
Relative to their potential danger, the definitions
are divided into four parts according to ANSI
Z535 Series.
!
!
FOR CALIFORNIA INSTALLATIONS ONLY:
WARNING:
Cancer and Reproductive Harm
www.P65Warning.ca.gov
August 31, 2018 3069575
is warning does not mean that Hussmann prod-
ucts will cause cancer or reproductive harm, or
is in violation of any product-safety standards or
requirements. As claried by the California State
government, Proposition 65 can be considered
more of a ‘right to know’ law than a pure product
safety law. When used as designed, Hussmann
believes that our products are not harmful. 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.

P/N 9FQ6P11007900_B 1-1
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. Open Vertical 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
manufactured, 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. This model is Type II as
described below.
NSF/ANSI 7 Type II – Display Refrigerator / Freezer
Intended for 80°F / 55%RH Ambient Application
NSF/ANSI 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 correct 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
NSF/ANSI 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 currents around the merchandiser.
INSTALLATION
Recommended operating ambient
temperature is between 60°F (16°C)
to 80°F (27°C). Maximum relative
humidity is 55%.
Do NOT stand or walk on top of
merchandiser. Do not store items or
ammable materials atop the unit.

1-2 INSTALLATION
P/N 9FQ6P11007900_B U.S. & Canada 1-800-922-1919 • Mexico 01 800-890-2900 • www.hussmann.com
LOCATION (Continued)
Product should always be maintained at proper temperature. This means that from the time the
product is received, through storage, preparation and display, the temperature of the product must
be controlled to maximize the life of the product.
be sure to position self contained merchandisers properly.
SELF CONTAINED models have vented base panels to allow air circulation through the
condensing unit.
Allow for a minimum of 2 inches of clearance from walls, merchandisers, and any other large objects
near the merchandiser’s vented base panels. A minimum space of 2 inches should be left above
the case. Blocking or restricting air flow will adversely affect performance and may damage the
refrigeration system.
If the merchandiser is used or stored in a hot spring or coastal area, it may be damaged (due to
sulfur or salt). If the intention is to install the merchandiser in any of the above areas or locations,
contact the supplier or dealer where you purchased the merchandiser. Do not lay the case sideways
to move the case. This may cause damage. Case should be installed on a flat, level floor.
After installation, fix the case in place with the leveling legs (case option) to make sure that it does
not move. Or if the case has casters, lock the casters.
Do not store items or ammable materials
atop the unit.
DANGER
!
DANGER
!
CAUTION
!
WARNING
!
NOTE
NOTE
STOP STOP
IMPORTANT
ATTENTION
INSTALLER
NOTICE
Leveling Legs or Casters
Ground wire
Air inlet
Do not block this inlet
or the merchandiser
will not cool properly
Air Exhaust
(Optional)
Hanging
Wall
Floor
2-inch gap
required
(51 mm)
2-inch gap
required
(51 mm)
Wall