Hussmann DDS Quick guide

January 2006
HUSSMANN - GLOVERSVILLE
INSTALLATION & SERVICE
INSTRUCTIONS
FOR
DDS – DDSS SELF-CONTAINED AND REMOTE
Multi-deck, Spot display
Refrigerator Merchandisers
P/N OII – DDS, DDSS Merchandisers
January 2006
First Call for help (US and Canada):
1-800-922-1919
Soporte Tècnico y Asistencia (Mèxico):
01-800-522-1900
For a Service Network Locator and other
Information visit us at
www.hussmann.com
select Worldwide Locations

TABLE OF CONTENTS
SECTION 1 General Information Page 3
SECTION2 Installation Page4
SECTION3 Refrigeration Page5
Self Contained Models
SECTION4 Refrigeration Page6
Remote Models
SECTION 5 Electrical Page 12
SECTION 6 Replacement Parts List Page 14
SECTION 7 User Instructions Page 20
SECTION 8 Service Tips and Wiring Diagrams Page 22

Page 3
SECTION 1
GENERAL INFORMATION
MODEL DESCRIPTION
The DDS model series are multi-deck, spot merchandisers designed for medium temperature
applications such as: deli/dairy/beverage/floral. They are available as either remote type
models, which require separate condensing unit connections, or self-contained models. Each
self-contained model will have it’s own condensing unit, factory installed beneath the display
area of the case ready for operation when electrical service is connected.
The following table lists the standard models with a brief description of each, including the
electrical requirements of the self-contained model. Unless otherwise specified, the electrical
requirements for the remote model will be 120 volt, 60 hertz (Hz).
MODEL ELECTRICAL DESCRIPTION
MODEL
DESCRIPTION
ELECTRICAL SERVICE
DDS/DDF-4B Self-Contained 4’ Merchandiser 115 / 60 Hz / 1 ∅
DDS/DDF-4D/G Self-Contained 4’ Merchandiser 230v - 208v / 60 Hz / 1 ∅
DDS/DDF-6D/G Self-Contained 6’ Merchandiser 230v - 208v / 60 Hz / 1 ∅
DDS/DDF-8D/G Self-Contained 8’ Merchandiser 230v - 208v / 60 Hz / 1 ∅
DDS/DDF-4R Remote Type 4’ Merchandiser 115 / 60 Hz / 1 ∅
DDS/DDF-6R Remote Type 4’ Merchandiser 115 / 60 Hz / 1 ∅
DDS/DDF-8R Remote Type 4’ Merchandiser 115 / 60 Hz / 1 ∅
DDSS-4D/G Self-Contained 4’ Merchandiser 230v- 208v / 60 Hz / 1 ∅
Symbol
∅
denotes
PHASE
APPLICATION
These models are designed for use only in air-conditioned stores where temperature is 75
°
F or
less and relative humidity does not exceed 55%.
HUSSMANN - GLOVERSVILLE

03 Page4
SECTION 2
INSTALLATION
SHIPPING DAMAGE
All equipment should be examined for shipping damage before and during unloading. If there is
any damage, the carrier should be notified immediately and an inspection requested. The
delivery receipt must be noted that equipment was received damaged. If damage is of a
concealed nature, we suggest the carrier be contacted immediately, or no later than (3) days
following delivery. The consignee for all damages must file a claim with the carrier.
SHIPPING BRACES
Move the fixture as close as possible to its permanent location then remove all packaging and
shipping braces. Remove all separately packed accessories such as kits, shelves, etc.
EXTERIOR LOADING
These cases are not structurally designed to support excessive external loading such as the
weight of a person, therefore, do not walk on the top of these refrigerators or damage to the
refrigerator and serious personal injury could occur.
LOCATION
These refrigerators, like other open refrigerators, are sensitive to air disturbances. Air currents
passing around them will seriously impair their operation. Do not allow air-conditioning,
electric fans, open doors or windows, etc. to create air currents around these cases.
DO NOT INSTALL THE VENTED PANELS OF THE SELF-CONTAINED MODELS
AGAINST A WALL OR OTHER STORE FIXTURE.
Located in the lower front and rear of the self-contained models are vented panels. These panels
allow air circulation to the condensing unit. Blocking or restricting air circulation through these
panels can cause poor performance and damage the refrigeration system.
INSTALL THE REFRIGERATOR NO CLOSER THAN (4) FOUR INCHES FROM A WALL OR OTHER
STORE FIXTURES.
HUSSMANN - GLOVERSVILLE

07/02/03
Page 5
SECTION
3
REFRIGERATION
-
SELF CONTAINED MODELS
Each self-contained model is equipped with its own condensing unit located beneath the display
area. The unit will be charged per nameplate refrigerant and shipped fromthe factory with all
service valves open, completely ready for operation when electrical power has been connected.
REFRIGERANT
CHARGE
MODEL REFRIGERANT POUNDS OUNCES
DDS/DDF-4B R - 22 5 8
DDS/DDF-4D/G R - 22 5 8
DDS/DDF-6D/G R - 22 7 11
DDS/DDF-8D/G
R – 404A
8
2
DDS – 4D/G c/w
Hp
Condensing
Unit
R - 22
5
0
DDSS – 4D/G
R-22
5
8
CONTROLS and ADJUSTMENTS
REFRIGERATION
CONTROLS
DISCHARGE AIR
TEMPERATURE
DEFROST
FREQUENCY
DEFROST CONTROLS
PRESSURE
TERMINATION
FAILSAFE
28
°
to 34
°
F
Every
6 Hours
90 psig (R-22)
105 psig (R-404A)
45
Minutes
A refrigeration thermostat controls refrigeration temperature. The control is factory
installed in the control panel. Adjust this thermostat to maintain the discharge air
temperature shown. Measure discharge air temperatures at the center of the discharge
honeycomb.
Defrosts are time-initiated and pressure terminated. The defrost timer is factory set a
s
shown. Check that the above settings are implemented and correct, and that the cloc
k
indicated the correct time of day.
Defrost must be terminated by defrost termination setting.
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07/02/03 Page 6
SECTION 4
REFRIGERATION - REMOTE MODELS
REFRIGERANT PIPING
Refrigerant line connection sizes: All models LIQUID LINE 3/8” OD
SUCTION LINE 5/8” OD for 4’ & 6’ Models; 1 1/8” for all other models
These connections are made at the right hand end of the cases (facing front) beneath the
refrigerated display area. Refrigerant lines should be sized as shown on the refrigeration legend
(furnished by the owner). If a legend has not been furnished, refer to Section 12 of the
Hussmann Application Engineering Manual for guidance.
OUTLET LOCATION
The refrigerant line outlet is located at the right hand end of the refrigerator beneath the display
pans. After connections have been made, seal this outlet thoroughly both on the inside and the
outside. An aerosol dispensed urethane type of insulation is recommended.
LINE SIZING
Refrigerant lines should be sized as shown on the refrigeration legend prepared for the store and
as (furnished by the owner). If a legend has not been furnished, refer to Section 12 of the
Hussmann Application Engineering Manual for guidance.
OIL TRAPS
P-traps (oil traps) must be installed at the base of all suction line vertical risers.
PRESSURE DROP
Pressure drop reduces capacity of the refrigeration system. To minimize pressure drop, use
proper size tubing, keep the refrigerant line runs as short as possible and use a minimum number
of elbows. Where elbows are needed, use long radius elbows only.
PIPING INSULATION
For refrigerators with other than KOOLGAS defrost, the suction and liquid lines should be
clamped and/or taped together and insulated for a minimum of 30 feet from the refrigerator.
Refrigerators with KOOLGAS defrost should not have their liquid and suction lines in contact
with each other but are to be separately insulated for a minimum of 30 feet from the refrigerator.
Additional insulation for the balance of the refrigerant lines is recommended and required
wherever condensation and dripping would be objectionable.
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07/02/03 Page 7
EXPANSION VALVE ADJUSTMENT
Expansion valves must be adjusted to fully feed the evaporator. Before attempting to adjust
valves, make sure the evaporator is either clear of / or only lightly covered with frost, and that
the fixture is within 10°F of it’s expected operating temperature.
Adjust the valve as follows:
A. Attach a probe to the suction line near the expansion valve bulb.
B. Obtain a pressure reading from the factory installed Schraeder valve. Convert
the pressure reading to a saturated temperature for the appropriate refrigerant
Temperature B minus Temperature A = Superheat
Some “hunting” of the expansion valve is normal. The valve should be adjusted so that during
the hunting the greatest difference between the two temperatures is 3°F to 5°F.
With this adjustment, during a portion of the hunting the temperature difference between the
probes will be less than 3°F (at times as low as 0°F).
Make adjustments of no more than (1/2) turn of the valve stem at a time and wait for at
least fifteen minutes before rechecking the probe temperature and making further
adjustments.
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07/02/03 Page 8
REFRIGERATION & DEFROST CONTROLS FOR
CONVENTIONAL OPERATION (Single Compressor System)
Refrigeration temperature may be controlled by either the condensing unit’s low-pressure
control or by refrigeration thermostat (optional / one per condensing unit). Thermostatic control
is preferred since it will provide a more constant year-round control of temperature. The
thermostat may be field or factory installed, must have a differential of 3°F to 6°F and have its
sensing bulb located to monitor the air leaving the evaporator. One thermostat per condensing
unit is required and should be wired into the compressor motor contactor control circuit.
A pump down system is recommended for outdoor condensing units.
DEFROST:
DDS models have defrost cycles that are time initiated and time terminated.
REFRIGERATION CONTROLS DEFROST CONTROLSf
LOW PRESSURE CONTROL SETTINGS DEFROST TIMER
If used to control
dtemperature
If thermostat controls
etemperature
Discharge
Air
Temp
(Cut-out) (Cut-out) (Cut-in) (Cut-out) (Cut-in)
Defrost
Frequency
Failsafe
Length
Termination
Pressure
28°Fc
Convert
Temperatures
to Pressures for
type of
Refrigerant
Used
12°F 30°F -7°F 26°F
Every
6 Hours
45 Min 90 psig
cMeasure discharge air temperatures at the center of the honeycomb. If thermostat is
used to control temperature, set thermostat to open contacts at the discharge air
temperature given in the table.
dAdjust the cutout on the low-pressure control to stop the compressor at the discharge
temperature given in the table. Final adjustment should be made after refrigerator is
stocked with product. If cycle frequency is more than 4 times per hour, cycling should
produce an average discharge air temperature as shown above.
eThese settings are acceptable for outdoor unit applications when the coldest expected
ambient does not go below 0°F. If colder ambient temperatures are expected, set
control accordingly per “Hussmann Condensing Unit Installation Instructions.
fIf these spot display refrigerators are to be multiplexed with a different type refrigerator,
compare these defrost settings with those specified for the other refrigerator. If the
settings are not compatible, refer to page 15 (Controls & adjustments – Mixed
Multiplexing).
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07/02/03 Page 9
REFRIGERATION & DEFROST CONTROLS FOR
CONVENTIONAL OPERATION - Mixed Multiplexing (Parallel Racks)
Refrigeration temperature may be controlled by a refrigeration thermostat sensing discharge air
temperature. The thermostat controls a liquid line solenoid (optional) or a suction line solenoid
(optional). The use of an evaporator pressure regulator (EPR) is recommended to allow fixture
to refrigerate at steady levels.
DEFROST:
DDS models have defrost cycles that are time initiated and time terminated.
REFRIGERATION
CONTROLS
DEFROST CONTROLS d
DEFROST TIMER
Length of Defrost
MODEL
DISCHARGE
AIR TEMP c
(Cut-out)
DEFROST
Frequency Off-Time/Electric KOOLGAS
ALL 28°F Every 6 Hours 45 Min e14 Min
f
cDischarge air temperature is to be measured by attaching a service thermometer to the
discharge honeycomb at the centre of the case.
dAdjust the refrigeration thermostat or EPR valve to maintain the discharge air
temperature shown above.
eIf these spot display refrigerators are to be multiplexed with a different type refrigerator,
compare these defrost settings with those specified for the other refrigerator. If these
settings are not compatible, refer to the following page.
fKOOLGAS defrost is time initiated and time terminated. The defrost lengths listed
above are based upon laboratory testing but operation under actual store conditions may
require that they be lengthened to accomplish a thorough defrost. Some of the store
conditions that can contribute to a longer defrost are: low head pressure, long runs of
refrigerant lines, store ambient, fixture temperature operating lower than that
recommended, seasonal ambient changes etc.
Each system shown on the “store legend” must have staggered defrosts to maintain stable
compressor loading and a sufficient supply of defrost gas.
HUSSMANN - GLOVERSVILLE