Unitary products group DAHC180 User manual

GENERAL
These Model DHC units are single package air conditioners
designed for outdoor installation on a rooftop or a slab. These
units can be equipped with factory installed electric heaters for
cooling/heating applications.
The units are completely assembled on rigid, permanently
attachedbaserails.Allpiping,refrigerantcharge,andelectrical
wiring is factory installed and tested. The units require electric
power, duct connections and installation of fixed outdoor air
intake damper (units without economizer or motorized damper
option only) at the point of installation.
The supplemental electric heaters have nickel-chrome
elements and utilize single point power connection.
INSPECTION
Assoonasaunitisreceived,itshouldbeinspectedforpossible
damage during transit. If damage is evident, the extent of the
damageshould be notedon the carrier'sfreight bill. Aseparate
request for inspection by the carrier's agent should be made in
writing.
REFERENCE
Additional information on accessory installation and service
parts on this equipment is available in the following reference
forms:
•44-320-10 - Barometric Relief Damper Accessory
Renewal Parts:
•Refer to the Renewal Parts Manual for complete listing of
replacement parts on this equipment.
All forms referenced in this instruction may be ordered from:
Standard Register
2101 West Tecumseh Road
Norman, Oklahoma 73069
Toll Free Fax: [phone]
Toll Free Phone: [phone]
APPROVALS
Design certified by ETL & CGA as follows:
1. Foruseasacentralcoolingonlyunitwithorwithoutsupple-
mental electric heat.
2. For outdoor installation only.
3. For installation on combustible material.
SINGLE PACKAGE AIR CONDITIONERS
WITH OR WITHOUT
SUPPLEMENTAL ELECTRIC HEAT
INSTALLATION
INSTRUCTION Supersedes: 530.22-N5W (1194) 530.22-N5W (500)
MODELS DAHC180 & 240
(9.5 EER)
035-12558
208/230/575 VOLT
MODELS ONLY
Installershouldpayparticularattentiontothewords: NOTE,CAUTIONand WARNING.Notesare intendedtoclarifyormakethe
installation easier. Cautions are given to prevent equipment damage. Warnings are given to alert installer that personal injury
and/or equipment damage may result if installation procedure is not handled properly.
208/230/460 VOLT
MODELS ONLY
CAUTION
THIS PRODUCT MUST BE INSTALLED IN STRICT COMPLIANCE
WITH THE ENCLOSED INSTALLATION INSTRUCTIONS AND
ANY APPLICABLE LOCAL, STATE, AND NATIONAL CODES
INCLUDING, BUT NOT LIMITED TO, BUILDING, ELECTRICAL,
AND MECHANICAL CODES.
WARNING
INCORRECT INSTALLATION MAY CREATE A CONDITION
WHERE THE OPERATION OF THE PRODUCT COULD CAUSE
PERSONAL INJURY OR PROPERTY DAMAGE

2 Unitary Products Group
530.22-N5W
General................................................................................1
Inspection............................................................................1
Reference............................................................................1
Approvals ............................................................................1
Nomenclature......................................................................2
INSTALLATION
Limitations ...........................................................................3
Location...............................................................................3
Rigging and Handling..........................................................3
Clearances ..........................................................................3
Ductwork .............................................................................3
Fixed Outdoor Air Intake Damper........................................4
Condensate Drain ...............................................................4
Compressors.......................................................................4
Filters...................................................................................4
Service Access....................................................................4
Thermostat ..........................................................................4
Power and Control Wiring ...................................................4
Optional Electric Heaters.....................................................5
Optional Economizer/Mot. Damper Rain Hood ...................5
Optional Power Exhaust Rain Hood....................................7
OPERATION
Cooling System .................................................................14
Preliminary Operation Cooling ..........................................14
Cooling Sequence of Operation ........................................14
Safety Controls..................................................................14
Heating Sequence of Operation........................................14
Heat Anticipator Setpoints.................................................15
Checking Supply Air CFM .................................................15
Secure Owner's Approval..................................................16
MAINTENANCE
Normal Maintenance .........................................................16
TABLES
No. Description Page
1 Unit Application Data.................................. 3
2 Control Wire Sizes ..................................... 5
3 Electric Heat Application Data.................... 5
4 Physical Data............................................. 8
5 Supply Air Blower Perf. 15 Ton .................. 10
6 Supply Air Blower Perf. 20 Ton .................. 11
7 Static Resistances...................................... 12
8 Power Exhaust Performance ..................... 12
9 Blower Motor and Drive Data..................... 12
10 Electrical Data (Basic Units)....................... 13
11 Electrical Data (Units w/Elec. Heat)........... 13
12 Heat Anticipator Setpoints.......................... 15
FIGURES
No. Description Page
1 Typical Rigging........................................... 3
2 Center of Gravity........................................ 3
3 Fixed Outdoor Air Damper......................... 4
4 Recommended Drain Piping...................... 4
5 Typical Field Wiring.................................... 5
6 Adjusting Enthalpy Setpoint....................... 8
7 Dimensions and Clearances...................... 9
8 Belt Adjustment.......................................... 15
9 Pressure Drop versus Supply Air CFM...... 15
TABLE OF CONTENTS
D A H C - T 08 8E
PRODUCT NOMENCLATURE
PRODUCT GENERATION
A = 1st Generation
PRODUCT CATEGORY
D = Single Package Air Conditioner
(Air-Cooled)
PRODUCT IDENTIFIER
HC = Cooling only or
Electric/Electric VOLTAGE CODE
-T = 208/230-3-60
-W = 460-3-60
-X = 575-3-60
NOMINAL COOLING
CAPACITY
180 = 15 Ton
240 = 20 Ton
FACTORY INSTALLED
OPTION CODE
A = Sing. Input Economizer
C = Sing. Input Economizer
w/ Power Exhaust
R = Motorized Outdoor
Air Damper
1 10
NOMINAL HEATING
CAPACITY
ELECTRIC
018 = 18 KW
036 = 36 KW
054 = 54 KW
072 = 72 KW
A
FACTORY INSTALLED
HEAT
A = No Heat
E = Electric

LIMITATIONS
These units must be installed in accordance with the following
national and local safety codes:
In U.S.A.:
1. National Electrical Code ANSI/NFPA No. 70.
2. Local electric utility requirements.
In Canada:
1. Current Canadian Electrical Code CSA C22.1.
2. Local electrical codes.
Refer to Table 1 for Unit Application Data and to Table 2 for
Electric Heat Application Data.
If components are to be added to a unit to meet local codes,
they are to be installed at the dealer's and/or the customer's
expense.
Size of unit for proposed installation should be based on heat
loss/heat gain calculation made according to the methods of
the Air Conditioning Contractors of America (ACCA).
LOCATION
Use the following guidelines to select a suitable location for
these units.
1. Unit is designed for outdoor installation only.
2. Outdoorcoilsmusthaveanunlimitedsupplyofair.Wherea
choice of location is possible, position the unit on either
north or east side of building.
3. For ground level installation, use a level concrete slab with
a minimum thickness of 4 inches. The length and width
should be at least 6 inches greater than the unit base rail
dimensions. Do not tie slab to the building foundation.
4. Roof structures must be able to support the weight of the
unit and its options and/or accessories. Unit must be
installed on a solid level roof curb or appropriate angle iron
frame.
CAUTION: If a unit is to be installed on a roof curb or spe-
cial frame other than a CES roof curb, gasket-
ingmust beapplied to all surfaces that come in
contact with the unit underside.
5. Maintain level tolerance to 1/2 inch maximum across the
entire length or width of the unit.
RIGGING AND HANDLING
Exercise care when moving the unit. Do not remove any
packaging until the unit is near the place of installation. Rig the
unit by attaching chain or cable slings to the round lifting holes
provided in the base rails. Spreaders, whose length exceeds
thelargerdimensionacrosstheunit, MUST beusedacrossthe
top of the unit. Refer to Figure 1.
Unitsmayalsobemovedorliftedwithaforklift,fromthefrontor
rear only, providing that an accessory skid is used.
LENGTHOFFORKSMUSTBEAMINIMUMOF90-INCHES.
RefertoTable4forunitweightsandtoFigure2forapproximate
center of gravity.
CLEARANCES
All units require certain clearances for proper operation and
service. Refer to Figure 9 for the clearances required for
combustibleconstruction,servicing,andproperunitoperation.
WARNING: Donotpermitoverhangingstructuresorshrubsto
obstruct outdoor air discharge outlet.
DUCTWORK
Ductwork should be designed and sized according to the
methods in Manual Q of the Air Conditioning Contractors of
America (ACCA).
A closed return duct system shall be used. This shall not
preclude use of economizers or outdoor fresh air intake. The
supply and return air duct connections at the unit should be
made with flexible joints to minimize transmission of noise.
The supply and return air duct systems should be designed for
the CFM and static requirements of the job. They should NOT
be sized to match the dimensions of the duct connections on
the unit.
CAUTION: When fastening ductwork to side duct flanges on
the unit, insert screws through duct flanges only.
DO NOT insert screws through casing.
Outdoor ductwork must be insulated and
waterproofed.
Refer to Figure 9 for information concerning side and bottom
supply and return air duct openings.
Unitary Products Group 3
530.22-N5W
INSTALLATION
Model Size 15 TON 20 TON
Voltage Variation,
Min. / Max.1208/230-3-60 187 / 253
460-3-60 414 / 506
575-3-60 518 / 630
Supply Air CFM, Min. / Max. 45002/ 7200 6000 / 9400
Wet Bulb Temperature (°F)
of Air on Indoor Coil
Min. / Max. 57 / 72
Dry Bulb Temperature (°F)
of Air on Outdoor Coil
Min. / Max. 25 / 120
1Utilization range “A” in accordance with ARI Standard 110.
25,000 CFM on 15 ton models with either a 54 or 72 KW heater at 208/230 volts.
TABLE 1 - UNIT APPLICATION DATA
FIG. 1 - TYPICAL RIGGING
FIG. 2 - CENTER OF GRAVITY

FIXED OUTDOOR AIR INTAKE DAMPER
This damper is shipped inside the return air compartment. It is
completely assembled and ready for installation. A damper
baffle inside the hood is adjustable to provide variable
amounts of outdoor air intake on units that are not provided
with an economizer or a motorized damper option. Refer to
Figure 3.
Gasketing and mounting screws are provided in a parts bag
attached to the hood assembly. Apply gasketing to the three
flangesurfaces on the hood priorto installing the hood. Extend
gasketing 1/4 inch beyond the top and bottom of the two side
flanges to insure adequate sealing.
Adjusting the damper to the desired air flow may be done
before mounting the hood into position or (after installation) by
removing the front hood panel or the screen on the bottom of
the hood. Damper baffle in position 1 will allow approximately
10%recirculatedairflow, position2approximately15%and,to
allow approximately 25%, remove the damper baffle.
On units with bottom return air applications, install the damper
assembly over the opening in the side return air access panel.
Remove and discard the opening cover and the covering over
the hood mounting holes (used for shipping) before installing.
Secure with the screws provided.
On units with side return air applications, install the damper
assembly on the return air ductwork as close to the unit as
possible. Cut an opening 16 inches high by 18 inches wide in
the ductwork to accommodate the damper. Using the holes in
the hood flanges as a template, drill 9/64 inch dia. (#26 drill)
holes into the ductwork and secure with the screws provided.
CAUTION: If outdoor air intake will not be required on units
with bottom return air applications, the damper
assembly should still be mounted on the side
returnairaccesspanel,pertheinstructionsabove,
to insure moisture is not drawn into the unit during
operation. The covering over the mounting holes
onlyneedberemoved.Do not remove the opening
cover.
CONDENSATE DRAIN
Plumbing must conform to local codes. Use a sealing
compound on male pipe threads. Install a condensate drain
line from the one-inch NPT female connection on the unit to an
open drain.
An alternate drain connection (one-inch NPT female coupling)
is provided inboard on the same centerline as the exterior
location.
NOTE: The condensate drain line MUST be trapped to pro-
vide proper drainage. See Figure 4.
COMPRESSORS
Unitsareshippedwithcompressormountingsfactory-adjusted
and ready for operation.
CAUTION: Do Not loosen compressor mounting bolts.
FILTERS
Two-inchfiltersaresuppliedwitheachunit.Filtersmustalways
be installed ahead of the indoor coil and must be kept clean or
replaced with same size and type. Dirty filters will reduce the
capacity of the unit and will result in frosted coils or safety
shutdown.Minimum filter areaandrequiredsizesareshownin
Table 4.
SERVICE ACCESS
Access to all serviceable components is provided by the
following removable panels:
•Compressor compartment
•Electric Heat compartment
•Side Supply & Return Air compartments (Two panels)
•Blower compartment (Three panels)
•Main control box
•Filter compartment
•Outdoor Air compartment (Two panels)
Refer to Figure 9 for location of these access panels.
CAUTION: Make sure that all screws and panel latches are
replaced and properly positioned on the unit to
maintain an air-tight seal.
THERMOSTAT
The room thermostat should be located on an inside wall
approximately 56 inches above the floor where it will not be
subject to drafts, sun exposure or heat from electrical fixtures
or appliances. Follow manufacturer's instructions enclosed
withthermostatfor general installationprocedure.Colorcoded
insulated wires (#18 AWG) should be used to connect
thermostat to unit.
POWER AND CONTROL WIRING
Field wiring to the unit must conform to provisions of the
National Electrical Code, ANSI / NFPA No. 70 (in U.S.A.),
currentCanadianElectricCode(CEC)CSAC22.1 (inCanada)
and/orlocalordinances.Theunitmustbeelectricallygrounded
in accordance with NEC and CEC (as specified above) and/or
local codes. Voltage tolerances which must be maintained at
the compressor terminals during starting and running
conditions are indicated on the unit Rating Plate and Table 1.
The internal wiring harness furnished with this unit is an
integral part of a ETL and CGA design certified unit. Field
alteration to comply with electrical codes should not be
required.
4 Unitary Products Group
530.22-N5W
FIG. 3 - FIXED OUTDOOR AIR DAMPER
FIG. 4 - RECOMMENDED DRAIN PIPING

Fuses are supplied, where required, by the factory. Some KW
sizes require fuses and others do not. Refer to Table 3 for
minmum CFM limitations and to Table 11 for electrical data.
OPTIONAL ECONOMIZER/MOTORIZED DAMPER
RAIN HOOD
The instruction for the optional economizer/motorized damper
rain hood can be found in form 44-320-2. Use these
instructions when field assembling an economizer rain hood
onto a unit. The outdoor and return air dampers, the damper
actuator, the damper linkage,the outdoor and returnair divider
baffles, and all the control sensors are factory mounted as part
of the “Factory installed” economizer option.
ENTHALPY SET POINT ADJUSTMENT
Remove the economizer access panel from the unit to check
the following adjustments. Loosen but do not remove the two
panel latches.
CAUTION: Extreme care must be exercised in turning both
the setpoint and minimum position adjusting
screws to prevent twisting them off.
6. The enthalpy setpoint may now be set by selecting the
desired setpoint shown in Figure 8. Adjust by carefully
turning the setpoint adjusting screw to the “A”, “B”, “C” or
“D” setting corresponding to the lettered curve.
7. To check that the damper blades move smoothly without
binding, carefully turn the minimum position adjusting
screw fully clockwise and then energize and de-energize
terminals “R” to “G”. With terminals “R” to “G” energized,
turntheminimumpositionscrewcounterclockwiseuntilthe
desired minimum position has been attained.
8. Replace the economizer access panel. Reposition the two
latches horizontally and retighten the screws.
POWER EXHAUST/BAROMETRIC RELIEF
DAMPER AND RAIN HOOD OPTION
The instructions for the power exhaust/barometric relief
damper and rain hood can be found in form 44-320-10. The
exhaustfan,allsupporting brackets,angles,andthewiringare
factory installed as part of the power exhaust option.
All of the components, including the dampers, hardware, and
mountinginstructionsareshippedinasinglepackageexternal
from theunit.Thehoodmustbefieldassembledandinstalled.
6 Unitary Products Group
530.22-N5W

Unitary Products Group 7
530.22-N5W
FIG. 6 - ENTHALPY SETPOINT ADJUSTMENT

8 Unitary Products Group
530.22-N5W
TABLE 4 - PHYSICAL DATA
MODELS UNIT SIZE
15 TON 20 TON
SUPPLY AIR
BLOWER CENTRIFUGAL BLOWER (Dia. x Wd. in.) 15 x 15 18 x 15
FAN MOTOR HP 5 7.5
EVAPORATOR
COIL
ROWS DEEP 4 4
FINS PER INCH 13.5 13.5
FACE AREA (Sq. Ft.) 15.5 20.5
CONDENSER
FANS
(Two Per Unit)
PROPELLER DIA. (in.) (Each) 30 30
FAN MOTOR HP (Each) 1 1
NOM. CFM (Each) 6500 7200
CONDENSER
COILS
(Two per unit)
ROWS DEEP (Each) 2 2
FINS PER INCH (Each) 13 20
FACE AREA (Sq. Ft.) (Each) 36.0 43.3
COMPRESSOR
(Qty. Per Unit) 10 TON TANDEM 1* 2
5 TON HERMETIC 1 -
AIR
FILTERS
QUANTITY PER UNIT (16" X 20" X 2") - 4
QUANTITY PER UNIT (16" X 25" X 2") - 4
QUANTITY PER UNIT (18" X 24" X 2") 5 -
TOTAL FACE AREA (sq. ft.) 15.0 20.0
CHARGE REFRIGERANT 22
(lbs./oz.) SYSTEM NO. 1 20/8 18/8
SYSTEM NO. 2 10/8 18/8
*This compressor will be energized first.
OPERATING WEIGHTS (LBS.) 15 TON 20 TON
Basic Unit Cooling Only 1900 2100
Options
Economizer 160
Economizer with
Power Exhaust 245
Motorized Damper 150
Electric Heat
(Nominal KW)
18 KW 25
36 KW 30
54 KW 35
72 KW 40
Accessories Roof Curb 175 185 Barometric Damper 45 45
Wood Skid 200 220

Unitary Products Group 9
530.22-N5W
FIG. 7 - DIMENSIONS & CLEARANCES - 15 & 20 TON
DUCT COVERS - Units are shipped with the bottom
duct openings covered. An accessory flange kit is avail-
able for connecting side ducts.
For bottom duct applications:
1. Remove the side panels from the supply and return
air compartments to gain access to the bottom
supply and return air duct covers.
2. Remove and discard the bottom duct covers. (Duct
openings are closed with sheet metal covers except
when the unit includes a power exhaust option. The
coveringconsistsofaheavyblackpapercomposition.)
3. Replace the side supply and return air compartment
panels.
For side duct applications;
1.Replacethesidepanelsonthesupplyandreturnair
compartments with the accessory flange kit panels.
2. Connect ductwork to the duct flanges on the rear of
the unit.
RETURN AIR
OUTDOOR AIR
(Economizer)
SUPPLY AIR
CONDENSER AIR
DETAIL “X” (ACCESSORY SIDE SUPPLY AND RETURN AIR OPENINGS)
Front 36"
Back 24" (Less Economizer)
49" (With Economizer)
Left Side (Filter Access) 24" (Less Economizer)
54" (With Economizer)
Right Side (Cond. Coil) 36"
Below Unit120"
Above Unit272" With 36" Maximum
Horizontal Overhang
(For Condenser Air
Discharge Outlet)
NOTE: Unit and ductwork are approved for zero clearance to combustible
materials when equipped with electric heat.
1Units (applicable in U.S.A. only) may be installed on combustible floors made
from wood or class A, B or C roof covering material.
2Units must be installed oudoors. Overhanging structures or shrubs should
not obstruct condenser air discharge outlet.
Alldimensionsare ininches.They aresub-
ject to change without notice. Certified di-
mensions will be provided upon request.
HOLE OPENING SIZE
(DIA.) USED FOR
A1-1/8" KO Control
Wiring Front
3/4" NPS (Fem.) Bottom
B3-5/8" KO Power
Wiring Front
3" NPS (Fem.) Bottom
UTILITIES ENTRY DATA
CLEARANCES

10 Unitary Products Group
530.22-N5W
TABLE 5 - SUPPLY AIR BLOWER PERFORMANCE (15 TON)
180 MBH - BOTTOM DUCT CONNECTIONS
BLOWER
SPEED,
(RPM)
MOTOR
PULLEY
(TURNS
OPEN)*
CFM
4500 5250 6000 6750 7200
ESP BHP KW ESP BHP KW ESP BHP KW ESP BHP KW ESP BHP KW
208 VOLT AND STANDARD DRIVE
850 6.0** 0.9 2.4 2.2 0.7 3.0 2.7 0.5 3.2 2.9 ------
870 5.5 1.0 2.5 2.3 0.8 3.1 2.8 0.6 3.5 3.1 0.2 4.1 3.7 - - -
915 4.5 1.1 2.6 2.4 0.9 3.4 3.0 0.7 3.7 3.3 0.3 4.4 3.9 0.2 4.5 4.0
965 3.5 1.2 2.9 2.6 1.0 3.6 3.2 0.8 4.0 3.6 0.5 4.7 4.2 0.4 4.9 4.4
980 3.0 1.3 3.0 2.7 1.1 3.7 3.3 0.9 4.1 3.7 0.6 4.8 4.3 0.5 5.1 4.6
1010 2.0 1.4 3.1 2.8 1.2 3.8 3.4 1.0 4.2 3.8 0.7 5.0 4.5 0.6 5.4 4.8
1040 1.0 1.5 3.2 2.9 1.3 3.9 3.5 1.1 4.5 4.0 0.9 5.2 4.7 0.7 5.7 5.1
208 VOLT AND HIGH SPEED DRIVE ACCESSORY
965 6.0 1.2 2.9 2.6 1.0 3.6 3.2 0.8 4.0 3.6 0.5 4.7 4.2 0.4 5.0 4.4
980 5.5 1.3 3.0 2.7 1.1 3.7 3.3 0.9 4.1 3.7 0.6 4.8 4.3 0.5 5.1 4.6
1025 4.5 1.5 3.2 2.9 1.3 3.9 3.5 1.1 4.5 4.0 0.8 5.1 4.6 0.7 5.6 5.0
1065 3.5 1.6 3.4 3.0 1.4 4.0 3.6 1.2 4.7 4.2 1.0 5.5 4.9 - - -
1095 3.0 1.7 3.5 3.1 1.5 4.2 3.8 1.3 4.9 4.4 1.2 5.7 5.1 - - -
1130 2.01.93.73.31.74.54.01.55.14.6------
1170 1.02.13.93.52.04.74.21.85.54.9------
230/460/575 VOLT AND STANDARD DRIVE
870 6.0** 1.0 2.4 2.2 0.8 3.1 2.8 0.6 3.5 3.1 0.2 4.1 3.7 - - -
915 5.0 1.1 2.6 2.4 0.9 3.3 3.0 0.7 3.7 3.3 0.3 4.4 3.9 0.2 4.5 4.0
965 4.0 1.2 2.9 2.6 1.0 3.6 3.2 0.8 4.0 3.6 0.5 4.7 4.2 0.4 5.0 4.4
980 3.5 1.3 3.0 2.7 1.1 3.7 3.3 0.9 4.1 3.7 0.6 4.8 4.3 0.5 5.1 4.6
1040 2.0 1.5 3.2 2.9 1.3 3.9 3.5 1.1 4.5 4.0 0.9 5.3 4.7 0.7 5.7 5.1
1065 1.0 1.6 3.3 3.0 1.4 4.0 3.6 1.2 4.7 4.2 1.0 5.5 4.9 - - -
230/460/575 VOLT AND HIGH SPEED DRIVE ACCESSORY
980 6.0 1.3 2.9 2.6 1.1 3.7 3.3 0.9 4.1 3.7 0.6 4.8 4.3 0.5 5.1 4.6
1040 4.5 1.5 3.2 2.9 1.3 3.9 3.5 1.1 4.5 4.0 0.9 5.3 4.7 0.7 5.7 5.1
1065 4.0 1.6 3.4 3.0 1.4 4.0 3.6 1.2 4.7 4.2 1.0 5.5 4.9 - - -
1095 3.5 1.7 3.5 3.1 1.5 4.2 3.8 1.3 4.9 4.4 1.2 5.7 5.1 - - -
1130 2.51.93.73.31.74.54.01.55.14.6------
1170 1.52.13.93.52.04.74.21.85.54.9------
1190 1.02.24.03.62.14.84.32.05.75.1------
NOTES: 1. Blower performance includes fixed outdoor air, two-inch T/A filters, a dry evaporator coil and no electric heat.
2. Refer to Page 12 for additional static resistances.
ESP = External Static Pressure available for the supply and return air duct system. All internal unit resistances have been de-
ducted from the total static pressure of the blower.
*DoNOTclose the pulley below 1 turn open.
** Factory setting.