Hussmann DDS, DDSS Installation And Service Instructions Manual
January 2006
INSTALLATION & SERVICE
INSTRUCTIONS
FOR
DDS – DDSS SELF-CONTAINED AND REMOTE
Multi-deck, Spot display
Refrigerator Merchandisers
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
HUSSMANN - GLOVERSVILLE
P/N OII – DDS, DDSS Merchand isers
January 2006
TABLE OF CONTENTS
SECTION 1 General Information Page 3
SECTION 2 Installation Page 4
SECTION 3 Refrigeration Page 5
Self Contained Models
SECTION 4 Refrigeration Page 6
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
SECTION 1
GENERAL INFORMATION
MODEL DESCRIPTION
The DDS model seri es are multi-deck, spot merchandisers designed for medium tem pe ratu re
area of the case ready for operation wh en electrical service is connec ted.
requi rements for the rem ote model will be 120 v olt, 60 hertz (Hz).
MODEL ELECTRICAL DESCRIPTION
MODEL
DESCRIPTION
ELECTRICAL SERVICE
Symbol
∅
den otes
APPLICATION
less and relative hu midity does not exceed 55%.
HUSSMANN - GLOVERSVILLE
applica ti ons such as : deli/dairy/bevera ge /floral. They are avail ab l e as eithe r remote ty pe
models, which requi re sepa rate condensing unit connections, or self -con tain ed m odels. Each
self -c ontai n ed model will have i t’s own c on de nsing unit, fac tory installed ben ea th the di s pl ay
The f ollowing table lists the standa rd models wi th a brief description of each, incl uding the
elec trical requi rem en ts of the self-con tained m odel. Unless otherwis e specifi ed , the elec trical
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
∅
∅
∅
∅
∅
∅
∅
∅
These models are designe d for use only in air-conditioned stores where temperature is 75°F or
03 Page 4
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.
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07/02/03
Page 5
SECTION
3
REFRIGERATION
-
SELF CONTAINED MODELS
Each self-contained model is eq uipped with its own condensing unit located ben eath the display
serv ice valves open, compl e tel y ready for operation when elec trical power h as been connected.
REFRIGERANT
CHARGE
DDS/DDF-8D /G
R – 404A
8
2
DDS – 4D/G c/w
Hp
Condens in g
Unit
R - 22
50DDSS – 4D/G
R-22
5
8
CONTROLS a nd ADJUSTMENTS
TEMPERATURE
FREQUENCY
FAILSAFE
28° to 34
°
F
Every
6 Hours
90 psig (R-22)
105 psi g (R-404A)
45
Minutes
honeycomb.
s
k
HUSSMANN - GLOVERSVILLE
area. The unit will be charged per nameplate refri ge rant and shipped from the fa ctory with all
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
REFRIGERATION
CONTROLS
DISCHARGE AIR
A ref rigeration thermostat con trol s refrige ration tempera ture . The control i s f actory
installed in th e c ontrol p anel. Adjust this thermostat to m aintai n th e discharge air
temperature sh own . Meas ure dis ch arg e air temperatures at the center of the discharge
Defrosts are time-initiated and pressure terminated. The defrost timer is factory set a
shown. Check that the above settings are imp lemented and correct, and that the cloc
indicated the correc t tim e of day.
Defrost m ust be terminated by def rost termi nation settin g.
DEFROST
DEFROST CONTROLS
PRESSURE
TERMINATION
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.
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
Discharge
Air
Temp
(Cut-out)
28°F
c
c
Convert
Temperatures
to Pressures for
type of
Refrigerant
Used
LOW PRESSURE CONTROL SETTINGS DEFROST TIMER
If used to control
temperature
d
(Cut-out) (Cut-in)
If thermostat controls
temperature
e
(Cut-out) (Cut-in)
12°F 30°F -7°F 26°F
Measure discharge air temperatures at the center of the honeycomb. If thermostat is
DEFROST CONTROLSf
Defrost
Frequency
Every
6 Hours
used to control temperature, set thermostat to open contacts at the discharge air
d
temperature given in the table.
Adjust 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.
e
These 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.
f
If 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).
Failsafe
Length
Termination
Pressure
45 Min 90 psig
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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.
MODEL
ALL
c
d
e
f
Each system shown on the “store legend” must have staggered defrosts to maintain stable
compressor loading and a sufficient supply of defrost gas.
Discharge air temperature is to be measured by attaching a service thermometer to the
discharge honeycomb at the centre of the case.
Adjust the refrigeration thermostat or EPR valve to maintain the discharge air
temperature shown above.
If 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.
KOOLGAS 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.
REFRIGERATION
CONTROLS
DISCHARGE
AIR TEMP c
(Cut-out)
28° F
DEFROST CONTROLS d
DEFROST
Frequency
Every 6 Hours
DEFROST TIMER
Length of Defrost
Off-Time/Electric
45 Min e
14 Min
KOOLGAS
f
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07/02/03 Page 10
REMOTE CONTROL KIT (Optional)
The control settings listed in the preceding tables are those that will provide proper case
performance. If these spot display refrigerators are to be multiplexed with different types of
refrigerator models, we suggest that each spot display refrigerator be equipped with a
“REMOTE CONTROL KIT”.
The remote control kit will insure better control of refrigeration temperature and provide
additional defrost controls that maybe needed since most other refrigerators do not have similar
defrost frequencies and terminations (fail safeguards) with these spot display refrigerators.
The remote-control kit will be factory installed below the display area of the spot display
refrigerator. A liquid line solenoid valve will also be installed.
The liquid line solenoid valve will open when energized. During refrigeration, the valve is
controlled by the refrigeration thermostat (close-on-rise of temperature) providing better and
more specific control of refrigeration temperature. The defrost timer controls the valve for
defrost; closing the valve for initiation; opening the valve at termination.
The remote control kit timer must be synchronized with the timer of the unit.
HUSSMANN - GLOVERSVILLE
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