Daikin DSG SERIES User manual

1
DSG SERIES
LIGHT COMMERCIAL PACKAGED GAS UNIT
3 to 5 Ton
ATTENTION INSTALLING PERSONNEL:
Prior to installation, thoroughly familiarize yourself with
this Installation Manual. Observe all safety warnings.
During installation or repair, caution is to be observed.
It is your responsibility to install the product safely and to
educate the customer on its safe use.
RECOGNIZE THIS SYMBOL AS A SAFETY RECAUTION.
These installation instructions cover the outdoor installation
of single package heating and cooling units. See the Spec-
ication Sheet applicable to your model for information re-
garding accessories.
*NOTE: Please contact your distributor or our website for
the applicable Specication Sheet referred to in this manual.
This Forced Air Central Unit Design Complies With Require-
ments Embodied In The American National Standard / Na-
tional Standard of Canada Shown Below.
ANSI Z21.47•CSA-2.3 Central Furnaces
O NLY PERSONNEL
THAT HAVE BEEN
TRAINED TO INSTALL , ADJUST ,
SERVICE OR
REPAIR ( HEREINAFTER , “ SERVICE ”) THE EQUIPMENT SPECIFIED IN THIS
MANUAL SHOULD SERVICE THE EQUIPMENT . T HE MANUFACTURER WILL NOT
BE
RESPONSIBLE
FOR
ANY
INJURY
OR
PROPERTY
DAMAGE
ARISING FROM
IMPROPER SERVICE OR SERVICE PROCEDURES . I F YOU SERVICE THIS UNIT , YOU
ASSUME RESPONSIBILITY FOR ANY INJURY OR PROPERTY DAMAGE WHICH MAY
RESULT . I
N
ADDITION , IN
JURISDICTIONS THAT REQUIRE
ONE
OR
MORE
LICENSES TO SERVICE THE EQUIPMENT SPECIFIED IN THIS MANUAL , ONLY
LICENSED PERSONNEL SHOULD SERVICE THE EQUIPMENT . I MPROPER
INSTALLATION , ADJUSTMENT , SERVICING OR REPAIR OF THE
EQUIPMENT
SPECIFIED IN THIS MANUAL , OR ATTEMPTING TO INSTALL , ADJUST , SERVICE OR
REPAIR THE EQUIPMENT SPECIFIED IN THIS MANUAL WITHOUT PROPER
TRAINING MAY RESULT IN PRODUCT DAMAGE , PROPERTY DAMAGE , PERSONAL
INJURY OR DEATH .
Index
REPLACEMENT PARTS............................................................2
SAFETY INSTRUCTIONS..........................................................2
GENERAL INFORMATION.........................................................4
UNIT LOCATION ........................................................................5
CLEARANCES ...........................................................................7
ROOF CURB POST-INSTALLATION CHECKS .........................7
ROOF TOP DUCT CONNECTIONS ..........................................7
RIGGING DETAILS ....................................................................8
ELECTRICAL WIRING ...............................................................9
GAS SUPPLY PIPING..............................................................11
PROPANE GAS INSTALLATIONS ...........................................12
CIRCULATING AIR AND FILTERS...........................................13
VENTING..................................................................................13
CONDENSATE DRAIN CONNECTION ...................................13
IOD-1024E
03/2019
Our continuing commitment to quality products may mean a change in specications without notice.
© 2016-2019
5151 San Felipe St., Suite 500, Houston, TX 77056
www.daikincomfort.com
INSTALLATION INSTRUCTIONS
WARNING
PROP 65 WARNING
FOR CALIFORNIA CONSUMERS
Cancer and Reproductive Harm -
www.P65Warnings.ca.gov
0140M00517-A

2
STARTUP, ADJUSTMENTS, AND CHECKS............................14
AIR FLOW ADJUSTMENTS.....................................................15
MOTOR SHEAVE ADJUSTMENTS .........................................16
GAS SYSTEM CHECK.............................................................17
NORMAL SEQUENCE OF OPERATION ................................19
MAINTENANCE .......................................................................22
TROUBLESHOOTING .............................................................23
APPENDIX A BLOWER PERFORMANCE TABLES ................25
DIRECT DRIVE ..................................................................25
DSG036 DOWN SHOT AND HORIZONTAL ..................25
DSG048 DOWN SHOT AND HORIZONTAL ..................26
DSG060 DOWN SHOT ..................................................27
DSG060 HORIZONTAL..................................................28
BELT DRIVE.......................................................................29
HIGH STATIC DOWN SHOT ..........................................30
STANDARD HORIZONTAL ............................................31
HIGH STATIC HORIZONTAL .........................................32
APPENDIX B ELECTRICAL DATA...........................................34
APPENDIX C UNIT DIMENSIONS...........................................35
APPENDIX D WIRING DIAGRMS........................................... 36
START-UP CHECKLIST ...........................................................58
REPLACEMENT PARTS
Ordering Parts
When reporting shortages or damages, or ordering repair
parts, give the complete unit model and serial numbers
as stamped on the unit’s nameplate.
Replacement parts for this appliance are available
through your contractor or local distributor. For the loca-
tion of your nearest distributor, consult the white business
pages, the yellow page section of the local telephone
book or contact:
HOMEOWNER SUPPORT
DAIKIN NORTH AMERICA LLC
19001 KERMIER ROAD, WALLER, TX 77484
855-770-5678
SAFETY INSTRUCTIONS
tOthe installer
Before installing this unit, please read this manual to
familiarize yourself on the specic items which must be
adhered to, including maximum external static pressure
to unit, air temperature rise, minimum or maximum CFM
and motor speed connections.
Keep this literature in a safe place for future reference.
IFTHE INFORMATION IN THESE INSTRUCTIONS IS NOT FOLLOWED
EXACTLY, AFIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY
DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
- DONOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS
AND LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE.
- WHAT TO DO IF YOU SMELL GAS:
* DONOT TRY TO LIGHT ANY APPLIANCE.
* DONOT TOUCH ANY ELECTRICAL SWITCH; DO NOT USE
ANY PHONE IN YOUR BUILDING.
* IMMEDIATELY CALL YOUR GAS SUPPLIER FROM A
NEIGHBORS PHONE. FOLLOW THE GAS SUPPLIERS
INSTRUCTIONS.
* IFYOU CANNOT REACH YOUR GAS SUPPLIER, CALL THE
FIRE DEPARTMENT.
- INSTALLATION AND SERVICE MUST BE PERFORMED BY AQUALIFIED
INSTALLER, SERVICE AGENCY OR THE GAS SUPPLIER
WARNING
D O NOT CONNECT TO OR USE ANY DEVICE THAT IS NOT DESIGN
CERTIFIED BY THE MANUFACTURER
FOR USE
WITH THIS UNIT .
S ERIOUS PROPERTY DAMAGE , PERSONAL INJURY , REDUCED
UNIT
PERFORMANCE AND /OR HAZARDOUS CONDITIONS MAY
RESULT
FROM THE USE OF SUCH NON - APPROVED DEVICES .
WARNING
S HEET
METAL PARTS , SCREWS , CLIPS AND
SIMILAR ITEMS INHERENTLY
HAVE SHARP EDGES , AND IT IS NECESSARY
THAT THE INSTALLER AND
SERVICE PERSONNEL EXERCISE CAUTION .
CAUTION
Failure to follow the safety warnings exactly could result in
serious injury, death or property damage.
Never test for gas leaks with an open ame.
Use a commercially available soap solution made specically
for the detection of leaks to check all connections. A re or
explosion may result causing property damage, personal injury
or loss of life.
WARNING
FIRE OR EXPLOSION HAZARD
AVERTISSEMENT
RISQUE D’INCENDIE OU D’EXPLOSION
Si les consignes de sécurité ne sont pas suivies à la lettre, cela
peut entraîner la mort, de graves blessures ou des dommages
matériels.
Ne jamais vérier la présence de fuites de gaz au moyen d’une
amme nue. Vérier tous les raccords en utilisant une solution
savonneuse commerciale conçue spécialement pour la détection
de fuites. Un incendie ou une explosion risque de se produire,
ce qui peut entraîner la mort, des blessures ou des dommages
matériels.

3
WARNING
S
HOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT OFF, TURN
OFF THE MANUAL GAS SHUTOFF VALVE EXTERNAL TO THE FURNACE BEFORE
TURNING OFF THE ELECTRICAL SUPPLY.
WARNING
TO AVOID PROPERTY DAMAGE, PERSONAL INJURY OR DEATH, DO NOT USE
THIS UNIT IF ANY PART HAS BEEN UNDER WATER. IMMEDIATELY CALL A
QUALIFIED SERVICE TECHNICIAN TO INSPECT THE FURNACE AND TO REPLACE
ANY PART OF THE CONTROL SYSTEM AND ANY GAS CONTROL HAVING BEEN
UNDER WATER.
T HIS UNIT MUST NOT BE USED AS A " CONSTRUCTION HEATER "
DURING THE FINISHING PHASES OF CONSTRUCTION ON A NEW
STRUCTURE . T HIS TYPE OF USE MAY RESULT IN PREMATURE
FAILURE OF THE UNIT DUE TO EXTREMELY LOW RETURN AIR
TEMPERATURE AND EXPOSURE TO CORROSIVE OR VERY
DIRTY
ATMOSPHERES .
HIGH VOLTAGE!
DISCONNECT ALL POWER BEFORE SERVICING OR
INSTALLING THIS UNIT. MULTIPLE POWER SOURCES MAY
BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH.
WARNING
WARNING
T
O PREVENT THE RISK OF PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH,
DO NOT STORE COMBUSTIBLE MATERIALS OR USE GASOLINE OR OTHER
FLAMMABLE LIQUIDS OR VAPORS IN THE VICINITY OF THIS APPLIANCE.
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each appliance
connected to the venting system being placed into operation
could result in carbon monoxide poisoning or death.
The following steps shall be followed with each appliance
connected to the venting system placed in operation, while any
other appliances connected to the venting system are not in
operation:
1. Seal any unused openings in the venting system.
2. Inspect the venting system for proper size and horizontal
pitch, as required by the National Fuel Gas Code, ANSI Z223.1 or
the Natural Gas and Propane Installation Code,
CSA B149.1-15 and these instructions. Determine that there is no
blockage or restriction, leakage, corrosion and other decien-
cies which could cause an unsafe condition.
3. As far as practical, close all building doors and windows and
all doors between the space in which the appliance(s) connect-
ed to the venting system are located and other spaces of the
building.
4. Close replace dampers.
5. Turn on clothes dryers and any appliance not connected to
the venting system. Turn on any exhaust fans, such as range
hoods and bathroom exhausts, so they shall operate at maxi-
mum speed. Do not operate a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance being
inspected in operation. Adjust thermostat so appliance shall
operate continuously.
7. Test for spillage from draft hood appliances at the draft hood
relief opening after 5 minutes of main burner operation. Use the
ame of a match or candle.
8. If improper venting is observed during any of the above tests,
the venting system must be corrected in accordance with the
National Fuel Gas Code ANSI Z223.1/NFPA 54 and/or National
Gas and Propane Installation Code CSA B149.1-15.
9. After it has been determined that each appliance connected
to the venting system properly vents when tested as outlined
above, return doors, windows, exhaust fans, replace dampers
and any other gas burning appliance to their previous
conditions of use.

4
WARNING
T
O PREVENT PROPERTY DAMAGE, PERSONAL INJURY OR DEATH, DUE TO FIRE,
EXPLOSIONS, SMOKE, SOOT, CONDENSATION, ELECTRIC SHOCK OR CARBON
MONOXIDE, THIS UNIT MUST BE PROPERLY INSTALLED, REPAIRED, OPERATED,
AND MAINTAINED.
GENERAL INFORMATION
For complete information and installation instructions for
models with DDC controls, see manual DK-DDC-TGD-XXX.
This unit is approved for outdoor installation ONLY.
Rated performance is achieved after 72 hours of operation.
Rated performance is delivered at the specied airow. See
product specication sheet for light commercial models.
Specication sheets can be found at www.daikincomfort.com
for Daikin brand products. Within the website, please select
the commercial products menu and then select the submenu
for the type of product to be installed, such as air conditioners
or heat pumps, to access a list of product pages that each
contain links to that model’s specication sheet.
To assure that your unit operates safely and efciently, it
must be installed, operated, and maintained in accordance
with these installation and operating instructions, all local
building codes and ordinances, or in their absence, with the
latest edition of the National Fuel Gas Code NFPA54/ANSI
Z223.1 and National Standard of Canada CAN/CSA B149
Installation Codes.
AVERTISSEMENT
RISQUE D’INTOXICATION AU MONOXYDE DE
CARBONE
Si les étapes décrites ci-dessous ne sont pas suivies pour
chacun des appareils raccordés au système de ventilation au
moment de sa mise en marche, cela peut entraîner une intoxica-
tion au monoxyde de carbone ou la mort. Les étapes suivantes
doivent être suivies pour chacun des appareils raccordés au
système de ventilation au moment de sa mise en marche, alors
que tous les autres appareils raccordés au système de ventila-
tion ne sont pas en marche :
1) Sceller toutes les ouvertures inutilisées du système de
ventilation.
2) Inspecter le système de ventilation an de vérier si la taille
et l’inclinaison par rapport à l’horizontale sont conformes aux
exigences du National Fuel Gas Code, ANSI Z223.1/NFPA 54 ou
du Code d’installation du gaz naturel et du propane, CSA B149.1
et à ces instructions. Vérier qu’il n’y a pas d’obstruction ou
de restriction, de fuite, de corrosion et d’autres problèmes qui
pourraient entraîner une situation dangereuse.
3) Si possible, fermer toutes les portes et fenêtres du bâtiment
ainsi que toutes les portes séparant l’endroit où se trouvent
les appareils raccordés au système de ventilation et les autres
zones du bâtiment.
4) Fermer le registre des foyers.
5) Mettre les sécheuses en marche ainsi que tous les autres
appareils qui ne sont pas raccordés au système de ventilation.
Mettre en marche tous les ventilateurs de tirage, comme celui
des hottes de cuisine et des salles de bains, et les régler à la
puissance maximale. Ne pas mettre en marche les ventilateurs
d’été.
6) Suivre les instructions d’allumage. Mettre en marche l’appa-
reil soumis à l’inspection. Régler le thermostat de manière à ce
que l’appareil fonctionne en continu.
7) Vérier la présence de fuite au niveau de l’ouverture du
coupe-tirage des appareils qui en sont dotés après 5 minutes
de fonctionnement du brûleur principal. Utiliser la amme d’une
allumette ou d’une bougie.
8) Si un problème de ventilation est observé pendant l’un des
essais décrits ci-dessus, des correctifs doivent être apportés
au système de ventilation conformément au National Fuel Gas
Code, ANSI Z223.1/NFPA 54 et (ou) au Code d’installation du gaz
naturel et du propane, CSA B149.1.
9) Une fois qu’il a été déterminé que chaque appareil raccordé
au système de ventilation fonctionne correctement au moyen
des essais décrits ci-dessus, les portes, les fenêtres, les ven-
tilateurs, les registres de foyer et tous les autres appareils de
combustion alimentés au gaz doivent être remis dans leur état
initial.

5
ePa regulatiOns
imPOrtant: the united states envirOnmental PrOtectiOn
agency (ePa) has issued variOus regulatiOns regarding the
intrOductiOn and disPOsal Of refrigerants in this unit. failure
tO fOllOw these regulatiOns may harm the envirOnment and can
lead tO the imPOsitiOn Of substantial fines. because regulatiOns
may vary due tO Passage Of new laws, we suggest acertified
technician PerfOrm any wOrk dOne On this unit. shOuld yOu have
any questiOns Please cOntact the lOcal Office Of the ePa.
natiOnal cOdes
This product is designed and manufactured to permit instal-
lation in accordance with National Codes. It is the installer’s
responsibility to install the product in accordance with National
Codes and/or prevailing local codes and regulations.
The heating and cooling capacities of the unit should be greater
than or equal to the design heating and cooling loads of the
area to be conditioned. The loads should be calculated by an
approved method or in accordance with ASHRAE Guide or
Manual J - Load Calculations published by the Air Conditioning
Contractors of America.
Obtain from:
American National Standards Institute
25 West 43rd Street, 4th Floor
New York, NY 10036
System design and installation should also, where applicable,
follow information presented in accepted industry guides such
as the ASHRAE Handbooks. The manufacturer assumes no
responsibility for equipment installed in violation of any code
or regulation. The mechanical installation of the packaged roof
top units consists of making nal connections between the unit
and building services; supply and return duct connections; and
drain connections (if required). The internal systems of the unit
are completely factory-installed and tested prior to shipment.
Units are generally installed on a steel roof mounting curb as-
sembly which has been shipped to the job site for installation
on the roof structure prior to the arrival of the unit. The model
number shown on the unit’s identication plate identies the
various components of the unit such as refrigeration tonnage,
heating input and voltage.
Carefully inspect the unit for damage including damage to the
cabinetry. Any bolts or screws which may have loosened in
transit must be re-tightened. In the event of damage, the re-
ceiver should:
1. Make notation on delivery receipt of any visible damage to
shipment or container.
2. Notify carrier promptly and request an inspection.
3. In case of concealed damage, carrier should be notied as
soon as possible-preferably within 5 days.
4. File the claim with the following supporting documents:
a. Original Bill of Lading, certied copy, or indemnity
bond.
b. Original paid freight bill or indemnity in lieu thereof.
c. Original invoice or certied copy thereof, showing trade
and other discounts or reductions.
d. Copy of the inspection report issued by carrier repre-
sentative at the time damage is reported to the carrier.
The carrier is responsible for making prompt inspection
of damage and for a thorough investigation of each
claim. The distributor or manufacturer will not accept
claims from dealers for transportation damage.
NOTE: When inspecting the unit for transportation damage,
remove all packaging materials. Recycle or dispose of the
packaging material according to local codes.
Pre-installatiOn checks
Carefully read all instructions for the installation prior to install-
ing unit. Ensure each step or procedure is understood and any
special considerations are taken into account before starting
installation. Assemble all tools, hardware and supplies need-
ed to complete the installation. Some items may need to be
purchased locally.
UNIT LOCATION
WARNING
TO PREVENT POSSIBLE EQUIPMENT DAMAGE, PROPERTY DAMAGE, PERSONAL
INJURY OR DEATH, THE FOLLOWING BULLET POINTS MUST BE OBSERVED
WHEN INSTALLING THE UNIT.
IMPORTANT NOTE: Remove wood shipping rails prior to instal-
lation of the unit.
all installatiOns:
imPOrtant nOte: Unit should be energized 24 hours prior to
compressor start up to ensure crankcase heater has sufcient-
ly warmed the compressors. Compressor damage may occur if
this step is not followed.
NOTE: Appliance is shipped from factory for vertical duct appli-
cation.
Proper installation of the unit ensures trouble-free operation.
Improper installation can result in problems ranging from
noisy operation to property or equipment damages, danger-
ous conditions that could result in injury or personal proper-
ty damage and that are not covered by the warranty. Give
this booklet to the user and explain it’s provisions. The user
should retain these instructions for future reference.
• For proper ame pattern within the heat exchanger and
proper condensate drainage, the unit must be mounted lev-
el.
• The ue outlet must be at least 12 inches from any opening
through which ue gases could enter a building, and at least
three feet above any forced air inlet located within ten feet.
The economizer/manual fresh air intake/motorized fresh air
intake and combustion air inlet mounted on the unit are not
affected by this restriction.
• To avoid possible corrosion of the heat exchanger, do not
locate the unit in an area where the outdoor air (i.e. com-
bustion air for the unit) will be frequently contaminated by
compounds containing chlorine or uorine. Common sourc-
es of such compounds include swimming pool chemicals
and chlorine bleaches, paint stripper, adhesives, paints,
varnishes, sealers, waxes (which are not yet dried) and
solvents used during construction and remodeling. Various
commercial and industrial processes may also be sources
of chlorine/uorine compounds.

6
• Minimum horizontal clearance of 48” from the furnace ue
discharge to any electric meters, gas meters, regulators
and relief equipment is required.
unit PrecautiOns
• Do not stand or walk on the unit.
• Do not drill holes anywhere in panels or in the base frame of
the unit except where indicated. Unit access panels provide
structural support.
• Do not remove any access panels until unit has been in-
stalled on roof curb or eld supplied structure.
• Do not roll unit across nished roof without prior approval of
owner or architect.
• Do not skid or slide on any surface as this may damage
unit base. The unit must be stored on a at, level surface.
Protect the condenser coil because it is easily damaged.
rOOf curb installatiOns Only:
Curb installations must comply with local codes and should be
done in accordance with the established guidelines of the Na-
tional Roong Contractors Association.
Proper unit installation requires that the roof curb be rmly and
permanently attached to the roof structure. Check for adequate
fastening method prior to setting the unit on the curb.
Full perimeter roof curbs are available from the factory and are
shipped unassembled. Field assembly, squaring, leveling and
mounting on the roof structure are the responsibility of the in-
stalling contractor. All required hardware necessary for the as-
sembly of the sheet metal curb is included in the curb accessory.
WARNING
T
O PREVENT POSSIBLE EQUIPMENT DAMAGE, PROPERTY DAMAGE, PERSONAL
INJURY OR DEATH, THE FOLLOWING BULLET POINTS MUST BE OBSERVED
WHEN INSTALLING THE UNIT.
• Sufcient structural support must be determined prior to
locating and mounting the curb and package unit.
• Ductwork must be constructed using industry guidelines.
The duct work must be placed into the roof curb before
mounting the package unit. Our full perimeter curbs include
duct connection frames to be assembled with the curb.
Cantilevered type curbs are not available from the factory.
• Curb insulation, cant strips, ashing and general roong
material are furnished by the contractor.
The curbs must be supported on parallel sides by roof mem-
bers. The roof members must not penetrate supply and re-
turn duct opening areas as damage to the unit might occur.
NOTE: The unit and curb accessories are designed to allow
vertical duct installation before unit placement. Duct instal-
lation after unit placement is not recommended.
• To avoid possible illness or death of the building occupants,
do NOT locate outside air intake device (economizer, man-
ual fresh air intake, motorized fresh air intake) too close to
an exhaust outlet, gas vent termination, or plumbing vent
outlet. For specic distances required, consult local codes.
• Allow minimum clearances from the enclosure for re pro-
tection, proper operation, and service access (see unit
clearances). These clearances must be permanently main-
tained.
• The combustion air inlet and ue outlet on the unit must
never be obstructed. If used, do not allow the economizer/
manual fresh air damper/ motorized fresh air damper to be-
come blocked by snow or debris. In some climates or loca-
tions, it may be necessary to elevate the unit to avoid these
problems.
• Damper must be in open position when appliance main
burner(s) is operating.
Le registre doit être ouvert lorsque tout brûleur principal de
l’appareil est en état de fonctionnement.
• When the unit is heating, the temperature of the return air
entering the unit must be a minimum of 55° F.
grOund level installatiOns Only:
• When the unit is installed on the ground adjacent to the
building, a level concrete (or equal) base is recommended.
Prepare a base that is 3” larger than the package unit foot-
print and a minimum of 3” thick.
• The base should also be located where no runoff of water
from higher ground can collect in the unit.
rOOf tOP installatiOns Only:
• To avoid possible property damage or personal injury, the
roof must have sufcient structural strength to carry the
weight of the unit(s) and snow or water loads as required by
local codes. Consult a structural engineer to determine the
weight capabilities of the roof.
• The unit may be installed directly on wood oors or on Class
A, Class B, or Class C roof covering material.
• To avoid possible personal injury, a safe, at surface for ser-
vice personnel should be provided.
• As indicated on the unit data plate, a minimum clearance of
36” to any combustible material is required on the furnace
access side of the unit. All combustible materials must be
kept out of this area.
• This 36” clearance must also be maintained to insure prop-
er combustion air and ue gas ow. The combustion air
intake and furnace ue discharge must not be blocked for
any reason, including blockage by snow.
• Adequate clearances from the furnace ue discharge to
any adjacent public walkways, adjacent buildings, building
openings or openable windows must be maintained in ac-
cordance with the latest edition of the National Fuel Gas
Code (ANSI Z223.1)

7
A LL CURBS LOOK SIMILAR . T O AVOID INCORRECT CURB
POSITIONING , CHECK JOB PLANS CAREFULLY AND VERIFY MARKINGS
ON CURB ASSEMBLY . I NSTRUCTIONS MAY VARY IN CURB STYLES AND
SUPERSEDES INFORMATION SHOWN .
CAUTION
See the manual shipped with the roof curb for assembly and
installation instructions.
CLEARANCES
24”
Min.* 24”
Min.*
36” Min.
*
Unit Clearances
*In situations that have multiple units, a 48” minimum clear-
ance is required between the condenser coils.
Clearance in accordance with local installation codes, the
requirements of the gas supplier and the manufacturer’s in-
stallation instructions.
Dégaugement conforme aux codes d’installation locaux,
aux exigences du fournisseur de gaz et aux instructions d’in-
stallation du fabricant.
Adequate clearance around the unit should be kept for safe-
ty, service, maintenance, and proper unit operation. A total
clearance of 75” on the main control panel side of the unit
is recommended to facilitate possible fan shaft, coil, electric
heat and gas furnace removal. A clearance of 48” is recom-
mended on all other sides of the unit to facilitate possible
compressor removal, to allow service access and to insure
proper ventilation and condenser airow. The unit must not
be installed beneath any obstruction. The unit should be in-
stalled remote from all building exhausts to inhibit ingestion
of exhaust air into the unit fresh air intake.
NOTE: If the 48” minimum is used on the control panel side
of the unit, a ue extension (MF# 220-GX-01) needs be to
installed to prevent ue gas recirculation.
INSULATED
PANELS
Roof Curb Installation
ROOF CURB POST-INSTALLATION CHECKS
After installation, check the top of the curb, duct connection
frame and duct anges to make sure gasket has been ap-
plied properly. Gasket should be rmly applied to the top
of the curb perimeter, duct anges and any exposed duct
connection frame. If gasket is loose, re-apply using strong
weather resistant adhesive.
PrOtrusiOn
Inspect curb to ensure that none of the utility services (elec-
tric) routed through the curb protrude above the curb.
IFPROTRUSIONS EXIST, DO NO ATTEMPT TO SET UNIT ON CURB.
CAUTION
ROOF TOP DUCT CONNECTIONS
Install all duct connections on the unit before placing the unit
on rooftop.
hOrizOntal discharge
To convert to horizontal discharge, remove the covers over
the horizontal duct connections (save washered screws).
Refer to IOD-7006 included in the literature pack for install-
ing horizontal duct covers to the downow duct connections.
Flexible duct connectors between the unit and ducts are rec-
ommended. Insulate and weatherproof all external ductwork
and joints as required and in accordance with local codes.

8
SUPPLY
12”
17” 7 3/8”
11” 4 7/8””
25”
6 3/16”
REMOVE
COVERS
Horizontal Discharge Duct Connections
RIGGING DETAILS
WARNING
TO PREVENT PROPERTY DAMAGE, THE UNIT SHOULD REMAIN IN AN UPRIGHT
POSITION DURING ALL RIGGING AND MOVING OPERATIONS. TO FACILITATE
LIFTING AND MOVING WHEN A CRANE IS USED, PLACE THE UNIT IN AN
ADEQUATE CABLE SLING.
IFUNITS ARE LIFTED TWO AT ATIME, THE FORK HOLES ON THE
CONDENSER END OF THE UNIT MUST NOT BE USED. MINIMUM FORK
LENGTH IS 42” TO PREVENT DAMAGE TO THE UNIT; HOWEVER, 48”
IS RECOMMENDED.
CAUTION
Provisions for forks have been included in the unit base
frame. No other fork locations are approved.
WARNING
T
O PREVENT POSSIBLE EQUIPMENT DAMAGE, PROPERTY DAMAGE, PERSONAL
INJURY OR DEATH, THE FOLLOWING BULLET POINTS MUST BE OBSERVED
WHEN INSTALLING THE UNIT.
• Unit must be lifted by the four lifting holes located at the
base frame corners.
• Lifting cables should be attached to the unit with shackles.
• The distance between the crane hook and the top of the unit
must not be less than 60”.
• Two spreader bars must span over the unit to prevent dam-
age to the cabinet by the lift cables. Spreader bars must
be of sufcient length so that cables do not come in contact
with the unit during transport. Remove wood struts mount-
ed beneath unit base frame before setting unit on roof curb.
These struts are intended to protect unit base frame from
fork lift damage. Removal is accomplished by extracting
the sheet metal retainers and pulling the struts through the
base of the unit. Refer to rigging label on the unit.
I mportant: If using bottom discharge with roof cu rb, ductwork
should be attached to the curb prior to installing the unit.
Ductwork dimensions are shown in Roof Curb Installation
Instructions.
Refer to the Roof Curb Installation Instructions for proper
curb installation. Curbing must be installed in compliance
with the National Roong Contractors Association Manual.
Lower unit carefully onto roof mounting curb. While rigging
unit, center of gravity will cause condenser end to be lower
than supply air end.
To assist in determining rigging requirements, unit weights
are shown as follows:
A
B
C
D
CG
SUPPLY
RETURN
EVAPORATOR COIL
CONDENSER
COIL
COMPRESSOR
Y
X
Corner & Center of Gravity Locations
A B C D
DSG036045* 37 30 590 565 107 176 107 176
DSG036070* 37 30 595 570 108 178 107 177
DSG036090* 37 30 600 575 109 179 108 179
DSG048070* 37 30 630 605 114 188 114 189
DSG048090* 37 30 635 610 115 190 115 190
DSG048115* 37 30 640 615 116 192 116 191
DSG060090* 34 28 640 615 116 192 116 191
DSG060115* 34 28 644 619 117 193 117 192
DSG060140* 34 28 645 620 117 193 117 193
Corner Weights (lbs)
Operating
Weight
Shipping
Weight
Y
(in)
X
(in)
A*
Model
* Note: Weights are calculated without accessories installed.

9
T O PREVENT SEVERE DAMAGE TO THE BOTTOM OF THE UNIT , DO NOT
FORK LIFT UNIT AFTER WOOD STRUTS HAVE BEEN REMOVED .
CAUTION
Bring condenser end of unit into alignment with the curb.
With condenser end of the unit resting on curb member and
using curb as a fulcrum, lower opposite end of the unit until
entire unit is seated on the curb. When a rectangular can-
tilever curb is used, care should be taken to center the unit.
Check for proper alignment and orientation of supply and
return openings with duct.
rigging remOval
T O PREVENT DAMAGE TO THE UNIT , DO NOT ALLOW CRANE HOOKS
AND SPREADER BARS TO REST ON THE ROOF OF THE UNIT .
CAUTION
Remove spreader bars, lifting cables and other rigging
equipment.
ELECTRICAL WIRING
HIGH VOLTAGE!
DISCONNECT ALL POWER BEFORE SERVICING OR
INSTALLING THIS UNIT. MULTIPLE POWER SOURCES MAY
BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH.
WARNING
HIGH VOLTAGE!
T O AVOID PERSONAL
INJURY OR
DEATH DUE TO
ELECTRICAL SHOCK , DO NOT TAMPER WITH FACTORY
WIRING . T HE INTERNAL POWER AND CONTROL WIRING
OF THESE UNITS ARE FACTORY
- INSTALLED AND HAVE
BEEN
THOROUGHLY TESTED PRIOR
TO SHIPMENT .
C
ONTACT YOUR LOCAL REPRESENTATIVE IF
ASSISTANCE IS REQUIRED .
WARNING
T O PREVENT DAMAGE TO THE WIRING , PROTECT WIRING FROM
SHARP EDGES . F OLLOW NATIONAL ELECTRICAL CODE AND ALL
LOCAL CODES AND ORDINANCES . D O NOT ROUTE WIRES THROUGH
REMOVABLE ACCESS PANELS .
CAUTION
C ONDUIT AND FITTINGS MUST BE WEATHER - TIGHT TO PREVENT
WATER ENTRY INTO THE BUILDING .
CAUTION
For unit protection, use a fuse or hacr circuit breaker that is
in excess of the circuit ampacity, but less than or equal to the
maximum overcurrent protection device. DO NOT EXCEED
THE MAXIMUM OVERCURRENT DEVICE SIZE SHOWN
ON UNIT DATA PLATE.
All line voltage connections must be made through weath-
erproof ttings. All exterior power supply and ground wiring
must be in approved weatherproof conduit.
The main power supply wiring to the unit and low voltage wir-
ing to accessory controls must be done in accordance with
these instructions, the latest edition of the National Electrical
Code (ANSI/NFPA 70), and all local codes and ordinances.
The unit is factory wired for the voltage shown on the unit’s
data plate. Refer to model nomenclature in Appendix B for
voltage requirement for your unit.
NOTE: If supply voltage is 208V, lead on primary of trans-
former(s) must be moved from the 230V to the 208V tap. Re-
fer to wiring diagram on unit for details.
Main power wiring should be sized for the minimum circuit am-
pacity shown on the unit’s database. Size wires in accordance
with the ampacity tables in Article 310 of the National Electri-
cal Code. If long wires are required, it may be necessary to in-
crease the wire size to prevent excessive voltage drop. Wires
should be sized for a maximum of 3% voltage drop.
CAUTION
TO AVOID PROPERTY DAMAGE OR PERSONAL INJURY DUE TO FIRE, USE
ONLY COPPER CONDUCTORS.
CAUTION
T
O PREVENT IMPROPER AND DANGEROUS OPERATION DUE TO WIRING ERRORS,
LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING CONTROLS.
V
ERIFY PROPER OPERATION AFTER SERVICING.
NOTE: A weather-tight disconnect switch, properly sized
for the unit total load, must be eld or factory installed. An
external eld supplied disconnect may be mounted on the
exterior panel.
Ensure the data plate is not covered by the eld-supplied
disconnect switch.
• Some disconnect switches are not fused. Protect the
power leads at the point of distribution in accordance with
the unit data plate.
• The unit must be electrically grounded in accordance with
local codes or, in the absence of local codes, with the lat-
est edition of the National Electrical Code (ANSI-NFPA 70).
A ground lug is provided for this purpose. Size grounding
conductor in accordance with Table 250-95 of the National
Electrical Code. Do not use the ground lug for connecting a
neutral conductor.
• Connect power wiring to the compressor contactor closest
to the entrance located within the main control box or to
electrical power block, if equipped.

10
HIGH VOLTAGE ENTRANCE
LOW VOLTAGE ENTRANCE
1:4
30 1/4”*
12 3/8”
(REMOVE PLUG)
41/2”
47 1/2” 7 1/2”
POWER THRU
THE CURB
3.5 DIA.
Electrical Entrance and Thru Curb
Unit is equipped with a Low Voltage Terminal Block and
has Single Point wiring to the contactor or power block, if
equipped.
lOw vOltage cOntrOl wiring
1. A 24V thermostat must be installed for unit
operation. It may be purchased with the unit or eld
-supplied. Thermostats may be programmable or
electromechanical as required.
2. Locate thermostat or remote sensor in the conditioned
space where it will sense average temperature. Do not
locate the device where it may be directly exposed to
supply air, sunlight or other sources of heat. Follow
installation instructions packaged with the thermostat.
3. Use #18 AWG wire for 24V control wiring runs not
exceeding 75 feet. Use #16 AWG wire for 24V control
wiring runs not exceeding 125 feet. Use #14 AWG wire
for 24V control wiring runs not exceeding 200 feet. Low
voltage wiring may be National Electrical Code (NEC)
Class 2 where permitted by local codes.
4. Route thermostat wires from sub-base terminals to the
unit. Control wiring should enter through the condenser
panel opening or through curb indicated in “Electrical
Entrance” gure. Connect thermostat and any accessory
wiring to low voltage terminal block TB1 in the main
control box.
LOW VOLTAGE
BLOCK
MAIN POWER
LOW VOLTAGE
ENTRANCE POWER THRU
THE CURB
Power and Low Voltage Block Connections
(NOTE: The locations of components may be different in some
models depending on the options installed.)
F AILURE OF UNIT DUE TO OPERATION ON
IMPROPER LINE VOLTAGE
OR WITH EXCESSIVE PHASE UNBALANCE CONSTITUTES PRODUCT
ABUSE IS NOT COVERED BY THE WARRANTY AND MAY CAUSE
SEVERE DAMAGE TO THE UNIT ELECTRICAL COMPONENTS .
WARNING
Areas Without Convenience Outlet
It is recommended that an independent 115V power source
be brought to the vicinity of the roof top unit for portable
lights and tools used by the service mechanic.
NOTE: Refer to local codes for requirements. These outlets
can also be factory installed.
units installed On rOOf tOPs
Main power and low voltage wiring may enter the unit
through the condenser end of unit or through the roof curb.
Install conduit connectors at the desired entrance locations.
External connectors must be weatherproof. All holes in the
unit base must be sealed (including those around conduit
nuts) to prevent water leakage into building. All required
conduit and ttings are to be eld supplied.
Supply voltage to roof top unit must not vary by more than
10% of the value indicated on the unit data plate. Phase
voltage unbalance must not exceed 2%. Contact your local
power company for correction of improper voltage or phase
unbalance.

11
NOTE: Field-supplied conduit may need to be installed de-
pending on unit/curb conguration. Use #18 AWG solid con-
ductor wire whenever connecting thermostat wires to termi-
nals on sub-base. DO NOT use larger than #18 AWG wire. A
transition to #18 AWG wire may be required before entering
thermostat sub-base.
NOTE: Refer to unit wiring diagrams for thermostat hook-
ups.
GAS SUPPLY PIPING
T O PREVENT PERSONAL INJURY OR DEATH DUE TO IMPROPER
INSTALLATION , ADJUSTMENT , ALTERATION , SERVICE OR
MAINTENANCE , REFER TO THIS MANUAL . F OR ADDITIONAL
ASSISTANCE OR INFORMATION , CONSULT A QUALIFIED INSTALLER ,
SERVICE AGENCY OR THE GAS SUPPLIER .
WARNING
IMPORTANT NOTE: This unit is factory set to operate on
natural gas at the altitudes shown on the rating plate.
T O AVOID PROPERTY DAMAGE , PERSONAL INJURY OR DEATH WHEN
EITHER USING PROPANE GAS ALONE OR AT HIGHER ALTITUDES ,
OBTAIN AND INSTALL THE PROPER CONVERSION KIT ( S ). F AILURE TO
DO SO CAN RESULT IN UNSATISFACTORY OPERATION AND / OR
EQUIPMENT DAMAGE . H IGH ALTITUDE KITS ARE FOR U.S.
I
NSTALLATIONS ONLY AND ARE NOT APPROVED FOR USE IN C ANADA .
WARNING
The rating plate is stamped with the model number, type of
gas and gas input rating. Make sure the unit is equipped to
operate on the type of gas available. Conversion to propane
(LP) gas is permitted with the use of the factory authorized
conversion kit (see the unit Technical Manual for the appropri-
ate kit). For High Altitude derates, refer to the latest edition of
the National Fuel Gas Code NFPA 54/ANSI Z223.1.
Installaon of this furnace at altudes above 7000 
(2134 m) shall be made in accordance with the Listed High Altude
Conversion Kit available with this furnace.
L’installation de ce générateur de chaleur à des altitudes
supérieures à 7000 pi (2134 m) doit être eectuée conformément
aux instrucons accompagnant la trousse de conversion pour haute
altude fournie avec cet appareil.
NATURAL Min. 5.0" W.C., Max. 10.0" W.C.
PROPANE Min. 11.0" W.C., Max. 14.0" W.C.
INLET GAS PRESSURE
Inlet Gas Pressure Must Not Exceed the Maximum Value Shown in Table Above.
The minimum supply pressure should not vary from that
shown in the table above because this could prevent the
unit from having dependable ignition. In addition, gas input
to the burners must not exceed the rated input shown on the
rating plate. Overring of the unit could result in premature
heat exchanger failure.
PiPing
IMPORTANT NOTE: To avoid possible unsatisfactory op-
eration or equipment damage due to under ring of equip-
ment, do not undersize the natural/propane gas piping from
the meter/tank to the unit. When sizing a trunk line, include
all appliances on that line that could be operated simultane-
ously.
The rating plate is stamped with the model number, type of
gas and gas input rating. Make sure the unit is equipped to
operate on the type of gas available. The gas line installa-
tion must comply with local codes, or in the absence of local
codes, with the latest edition of the National Fuel Gas Code
NFPA 54/ANSI Z223.1.
Natural Gas Connection
1/2 3/4 11 1/4 1 1 /2
10 132 278 520 1050 1600
20 92 190 350 730 1100
30 73 152 285 590 980
40 63 130 245 500 760
50 56 115 215 440 670
60 50 105 195 400 610
70 46 96 180 370 560
80 43 90 170 350 530
90 40 84 160 320 490
100 38 79 150 305 460
Pressure= .50 PSIG or less and Pressure Drop of 0.3" W.C.
(Based on 0.60 Specific Gravity Gas)
Natural Gas Capacity of Pipe
in Cubic Feet of Gas Per Hour (CFH)
Nominal Black Pipe Size (inches)
Length of
Pipe in Feet
Heating Value of Gas (BTU/Cubic Foot
CFH =
BTUH Furnace Input
Refer to the Proper Piping Practice drawing for the general
layout at the unit. The following rules apply:
1. Use black iron pipe and ttings for the supply piping. The
use of a ex connector and/or copper piping is permitted
as long as it is in agreement with local codes.
2. Use pipe joint compound on male threads only. Pipe joint
compound must be resistant to the action of the fuel used.
3. Use ground joint unions.
4. Install a drip leg to trap dirt and moisture before it can
enter the gas valve. The drip leg must be a minimum of
three inches long.
5. Use two pipe wrenches when making connection to the
gas valve to keep it from turning.
6. Install a manual shut-off valve in a convenient location
(within six feet of unit) between the meter and the unit.
7. Tighten all joints securely.
8. The unit must be connected to the building piping by one
of the following methods:
• Rigid metallic pipe and ttings
• Semirigid metallic tubing and metallic ttings (Aluminum al-
loy tubing must not be used in exterior locations)
• Listed gas appliance connectors used in accordance with
the terms of their listing that are completely in the same
room as the equipment

12
• In the prior two methods above the connector or tubing
must be protected from physical and thermal damage. Alu-
minum alloy tubing and connectors must be coated to pro-
tect against external corrosion when in contact with mason-
ry, plaster or insulation or are subject to repeated wettings
by liquids (water - not rain water, detergents or sewage).
BURNER
DOOR
DRIP
LEG
MANUAL
SHUT-OFF
GROUND JOINT
UNION
TBD
Proper Piping Practice
NOTE: The unit gas supply entrance is factory sealed with
plugs. Keep plugs in place until gas supply is ready to be
installed. Once ready, replace the plugs with the supplied
grommets and install gas supply line.
gas PiPing checks
CAUTION
T
O PREVENT PROPERTY DAMAGE OR PERSONAL INJURY DUE TO FIRE, THE
FOLLOWING INSTRUCTIONS MUST BE PERFORMED REGARDING GAS
CONNECTIONS AND PRESSURE TESTING:
•
T
HE UNIT AND ITS GAS CONNECTIONS MUST BE LEAK TESTED BEFORE
PLACING IN OPERATION.
B
ECAUSE OF THE DANGER OF EXPLOSION OR
FIRE, NEVER USE A MATCH OR OPEN FLAME TO TEST FOR LEAKS.
N
EVER
EXCEED SPECIFIED PRESSURES FOR TESTING.
H
IGHER PRESSURE MAY
DAMAGE GAS VALVE AND CAUSE OVERFIRING WHICH MAY RESULT IN
PREMATURE HEAT EXCHANGE FAILURE.
•
T
HIS UNIT AND ITS SHUT-OFF VALVE MUST BE DISCONNECTED FROM
THE GAS SUPPLY DURING ANY PRESSURE TESTING OF THAT SYSTEM AT
TEST PRESSURES IN EXCESS OF 1/2
PSIG
(3.48 K
P
A).
•
T
HIS UNIT MUST BE ISOLATED FROM THE GAS SUPPLY SYSTEM BY
CLOSING ITS MANUAL SHUT-OFF VALVE DURING ANY PRESSURE
TESTING OF THE GAS SUPPLY PIPING SYSTEM AT TEST PRESSURES
EQUAL TO OR LESS THAN 1/2
PSIG
(3.48 K
P
A).
WARNING
T
O AVOID PROPERTY DAMAGE OR PERSONAL INJURY, BE SURE THERE IS
NO OPEN FLAME IN THE VICINITY DURING AIR BLEEDING.
There will be air in the gas supply line after testing for leaks
on a new installation. Therefore, the air must be bled from
the line by loosening the ground joint union until pure gas is
expelled. Tighten union and wait for ve minutes until all gas
has been dissipated in the air. Be certain there is no open
ame in the vicinity during air bleeding procedure. The unit
is placed in operation by closing the main electrical discon-
nect switch for the unit.
PROPANE GAS INSTALLATIONS
WARNING
T O AVOID PROPERTY DAMAGE, PERSONAL INJURY OR DEATH DUE TO FIRE
OR EXPLOSION CAUSED BY A PROPANE GAS LEAK, INSTALL A GAS
DETECTING WARNING DEVICE.
S
INCE RUST CAN REDUCE THE LEVEL
OF ODORANT IN PROPANE GAS, A GAS DETECTING WARNING DEVICE
IS THE ONLY RELIABLE WAY TO DETECT A PROPANE GAS LEAK.
C
ONTACT A LOCAL PROPANE GAS SUPPLIER ABOUT INSTALLING A
GAS DETECTING WARNING DEVICE.
IMPORTANT NOTE: Propane gas conversion kits must be
installed to convert units to propane gas. NOx screens must
be removed before converting to LP. Remove burner as-
sembly and pull NOx screens from each burner tube. When
all the screens are out, reassemble the burner assembly
without the screens.
All propane gas equipment must conform to the safety stan-
dards of the National Board of Fire Underwriters (See NBFU
Manual 58).
For satisfactory operation, propane gas supply pressure
must be within 9.7 - 10.3 inches W.C. at the manifold with all
gas appliances in operation. Maintaining proper gas pres-
sure depends on three main factors:
1. Vaporization rate, which depends on (a) temperature of
the liquid, and (b) wetted surface area of the container or
containers.
2. Proper pressure regulation.
3. Pressure drop in lines between regulators, and between
second stage regulator and the appliance. Pipe size re-
quired will depend on length of pipe run and total load of
all appliances.
tanks and PiPing
Complete information regarding tank sizing for vaporization,
recommended regulator settings and pipe sizing is available
from most regulator manufacturers and propane gas sup-
pliers.
Since propane gas will quickly dissolve white lead or most
standard commercial compounds, special pipe dope must
be used. Shellac base compounds resistant to the actions
of liqueed petroleum gases such as Gasolac®, Stalactic®,
Clyde’s® or John Crane® are satisfactory.
See the following gure for typical propane gas piping.
200 PSIG
Maximum
5 to 15 PSIG
(20 PSIG Max.) Continuous
11" W.C.
Second Stage
Regulator
First Stage
Regulator
Typical Propane Gas Piping
rOOf tOP lOcatiOn and installatiOn
The gas supply piping location and installation for roof top units
must be in accordance with local codes or, in the absence of
locals codes, with ordinances of the latest edition of the National

13
Fuel Gas Code (ANSI Z223.1).
A manual gas shut off valve must be eld installed external to
the roof top unit. In addition, a drip leg must be installed near
the inlet connection. A ground joint union connection is required
between the external shut off valve and the unit connection to
the gas valve to permit removal of the burner assembly for ser-
vicing.
1. Route gas piping to unit so that it does not interfere with
the removal of access panels. Support and align piping to
prevent strains or misalignment of the manifold assembly.
2. All units are furnished with standard female NPT pipe
connections. Connection pipe size is 1/2” NPT on 045
to 140 mBH units. The size of the gas supply piping to
the unit must be based on length of run, number of units
on the system, gas characteristics, BTU requirement
and available supply pressure. All piping must be done
in accordance with local codes or, in the absence of lo-
cal codes, with the latest edition of the National Fuel Gas
Code (ANSI Z223.1).
NOTE: The gas connection size at the unit does NOT
establish the size of the supply line.
3. These units are designed for either natural or propane
(LP) gas and are specically constructed at the facto-
ry for only one of these fuels. The fuels are NOT inter-
changeable. However, the furnace can be converted in
the eld from natural gas to LP gas with the appropriate
factory kit (see unit Technical Manual for the appropriate
kit). Only a qualied contractor, experienced with natural
and propane gas systems, should attempt conversion. Kit
instructions must be followed closely to assure safe and
reliable unit operation.
4. With all units on a common line operating under full re,
natural gas main supply pressure should be adjusted to
approximately 7.0” w.c., measured at the unit gas valve.
If the gas pressure at the unit is greater than 10.5” w.c.,
the contractor must furnish and install an external type
positive shut off service pressure regulator. The unit will
not function satisfactorily if supply gas pressure is less
than 5.5” w.c. or greater than 10.5” w.c..
NOTE: A minimum horizontal distance of 48” between
the regulator and the furnace ue discharge is required.
5. With all units on a common line operating under full LP
gas main supply pressure should be at least 11.0” w.c.
and must be no greater than 13.0” w.c., measured at the
unit gas valve. Unit will not function satisfactorily if supply
gas pressure is less than 11.0” w.c. or greater than 13.0”
w.c..
6. All pipe connections should be sealed with a pipe thread
compound, which is resistant to the fuel used with the fur-
nace. A soapy water solution should be used to check all
joints for leaks. A tap is located on the entering side of the
gas valve for test gauge connection to measure supply
(main) gas pressure. Another tap is provided on the mani-
fold side of the gas valve for checking manifold pressure.
THIS UNIT AND ITS INDIVIDUAL SHUTOFF VALVE MUST BE
DISCONNECTED FROM THE GAS SUPPLY SYSTEM DURING ANY
PRESSURE TESTING OF THAT SYSTEM AT TEST PRESSURES IN
EXCESS OF 1/2 PSIG (13.8” W.C.).
WARNING
T HIS UNIT MUST BE ISOLATED FROM THE GAS SUPPLY PIPING
SYSTEM BY CLOSING ITS INDIVIDUAL MANUAL SHUTOFF VALVE
DURING ANY PRESSURE TESTING EQUAL TO OR LESS THAN 1/2
PSIG.
CAUTION
7. There must be no obstruction to prevent the ow of com-
bustion and ventilating air. A vent stack is not required
and must never be used. The power venter will supply
an adequate amount of combustion air as long as the air
passageways are kept free of any obstructions and the
recommended external unit clearances are maintained.
CIRCULATING AIR AND FILTERS
ductwOrk
The supply duct from the unit through a wall may be installed
without clearance. However, minimum unit clearances must
be maintained (see “Clearances” section). The supply duct
should be provided with an access panel large enough to
inspect the air chamber downstream of the heat exchanger.
A cover should be tightly attached to prevent air leaks.
Ductwork dimensions are shown in the roof curb installation
manual.
If desired, supply and return duct connections to the unit
may be made with exible connections to reduce possible
unit operating sound transmission.
VENTING
NOTE: Venting is self-contained.
On some models, the inductor motor is a dual voltage motor.
It is factory wired for 230 volts. If eld supply power is 208V,
the installer must swap the connections to the black and red
leads (located in the control box or burner compartment) to
ensure correct inductor motor operation.
CONDENSATE DRAIN CONNECTION
cOndensate drain cOnnectiOn
A 3/4” female NPT drain connection is supplied on the end
of the condensate pan, with an alternate connection on the
bottom of the pan. An external trap must be installed for
proper condensate drainage.

14
STANDARD
SIDE DRAIN
DRAIN PLUG
(FACTORY-INSTALLED)
Drain Pan (Side View)
NOTE: Trap should be deep enough to offset maximum
unit static difference. A minimum 4” trap is recommended.
Drain Plug Roof Curb
See NOTE
Base Rail
Open Vent 2” Min
Drain Connection
Install condensate drain trap as shown. Use 3/4” drain line
and ttings or larger. Do not operate without trap.
hOrizOntal drain
Drainage of condensate directly onto the roof may be ac-
ceptable (refer to local code). It is recommended that a small
drip pad of either stone, mortar, wood or metal be provided
to prevent any possible damage to the roof. When using the
horizontal drain connection, check the drain plug in bottom
connection to ensure it is tight.
vertical drain
To use the bottom drain connection, remove the drain plug
from the bottom connection and install it in the horizontal
connection.
cleaning
Due to the fact that drain pans in any air conditioning unit will
have some moisture in them, algae and fungus will grow due
to airborne bacteria and spores. Periodic cleaning is neces-
sary to prevent this build-up from plugging the drain.
STARTUP, ADJUSTMENTS, AND CHECKS
HIGH VOLTAGE!
OND THE
FRAME OF
THIS UNIT TO
THE BUILDING
ELECTRICAL GROUND BY USE
OF THE
GROUNDING TERMINAL PROVIDED OR OTHER
ACCEPTABLE MEANS . D
ISCONNECT ALL POWER BEFORE
SERVICING OR INSTALLING
THIS UNIT .
T
O AVOID PERSONAL INJURY OR
DEATH DUE TO
ELECTRICAL SHOCK , B
WARNING
Pre-startuP instructiOns - general
T O PREVENT PROPERTY DAMAGE OR PERSONAL INJURY , D O NOT
START THE UNIT UNTIL ALL NECESSARY PRE - CHECKS AND TESTS
HAVE BEEN PERFORMED .
CAUTION
Prior to the beginning of Startup, Adjustments, and Checks
procedures, the following steps should be completed in the
building.
MOVING MACHINERY HAZARD!
TOPREVENT POSSIBLE PERSONAL INJURY OR DEATH, DISCONNECT
POWER TO THE UNIT AND PADLOCK IN THE “OFF” POSITION BEFORE
SERVICNG FANS.
WARNING
This unit is equipped with an electronic ignition device to
automatically light the main burners. It also has a power vent
blower to exhaust combustion products.
On new installations, or if a major component has been re-
placed, the operation of the unit must be checked.
Check unit operation as outlined in the following instructions.
If any sparking, odors, or unusual sounds are encountered,
shut off electrical power and recheck for wiring errors, or ob-
structions in or near the blower motors. Duct covers must
be removed before operating unit.
The Startup, Adjustments, and Checks procedure provides
a step-by-step sequence which, if followed, will assure the
proper startup of the equipment in the minimum amount of
time. Air balancing of duct system is not considered part of
this procedure. However, it is an important phase of any air
conditioning system startup and should be performed upon
completion of the Startup, Adjustments, and Checks proce-
dure. The Startup, Adjustments, and Checks procedure at
outside ambients below 55°F should be limited to a readi-
ness check of the refrigeration system with the required nal
check and calibration left to be completed when the outside
ambient rises above 55°F.
temPOrary heating OrcOOling
If the unit is to be used for temporary heating or cooling, a
“Startup, Adjustments, and Checks” must rst be performed in
accordance with this manual. Damage or repairs due to failure
to comply with these requirements are not covered under the
warranty. After the machines are used for temporary heating or
cooling, inspect the coils, fans, and motors for unacceptable
levels of construction dust and dirt and install new lters.
cOntractOr resPOnsibility
The installing contractor must be certain that:
• All supply and return air ductwork is in place, properly
sealed, and corresponds with installation instructions.
• All thermostats are mounted and wired in accordance
with installation instructions.

15
• All electric power, all gas, hot water or steam line con-
nections, and the condensate drain installation have
been made to each unit on the job. These main sup-
ply lines must be functional and capable of operating all
units simultaneously.
• Requirements are met for venting and combustion air.
• Air lters are in place.
• Input rate and temperature rise are adjusted per rating
plate.
rOOf curb installatiOn check
Inspect the roof curb for correct installation. The unit and curb
assembly should be level. Inspect the ashing of the roof
mounting curb to the roof, especially at the corners, for good
workmanship. Also check for leaks around gaskets. Note any
deciencies in a separate report and forward to the contractor.
ObstructiOns, fan clearance and wiring
Remove any extraneous construction and shipping materi-
als that may be found during this procedure. Rotate all fans
manually to check for proper clearances and that they ro-
tate freely. Check for bolts and screws that may have jarred
loose during shipment to the job site. Retighten if necessary.
Re-tighten all electrical connections.
field duct cOnnectiOns
Verify that all duct connections are tight and that there is no air
bypass between supply and return.
filter sectiOn check
Remove lter section access panels and check that lters are
properly installed. Note airow arrows on lter frames.
Pre-startuP PrecautiOns
It is important to your safety that the unit has been properly
grounded during installation. Check ground lug connection in
main control box for tightness prior to closing circuit breaker
or disconnect switch. Verify that supply voltage on line side of
disconnect agrees with voltage on unit identication plate and
is within the utilization voltage range as indicated in Appendix
B Electrical Data.
System Voltage - That nominal voltage value assigned to a cir-
cuit or system for the purpose of designating its voltage class.
Nameplate Voltage - That voltage assigned to a piece of
equipment for the purpose of designating its voltage class and
for the purpose of dening the minimum and maximum voltage
at which the equipment will operate.
Utilization Voltage - The voltage of the line terminals of the equip-
ment at which the equipment must give fully satisfactory perfor-
mance. Once it is established that supply voltage will be maintained
within the utilization range under all system conditions, check and
calculate if an unbalanced condition exists between phases.
Calculate percent voltage unbalance as follows.
Three Phase Models Only
3) PERCENT VOLTAGE
UNBALANCE
2) MAXIMUM VOLTAGE DEVIATIONS
FROM AVERAGE VOLTAGE
1) AVERAGE VOLTAGE
HOW TO USE THE FORMULA:
EXAMPLE: With voltage of 220, 216, and 213
1) Average Voltage = 220+216+213=649 / 3 = 216
2) Maximum Voltage Deviations from Average Voltage = 220 - 216 = 4
3) Percent Voltage Unbalance = 100 x = = 1.8%
Percent voltage unbalance MUST NOT exceed 2%
.
4
216
400
216
= 100 X
AIR FLOW ADJUSTMENTS
When the nal adjustments are complete, the current draw
of the motor should be checked and compared to the full
load current rating of the motor. The amperage must not ex-
ceed the service factor stamped on the motor nameplate.
The total airow must not be less than that required for op-
eration of the electric heaters or the furnace.
If an economizer is installed, check the unit operating bal-
ance with the economizer at full outside air and at minimum
outside air.
NOTE: Never run CFM below 300 CFM per ton, evaporator
freezing or poor unit performance is possible.
Psc mOtOr
Adjust the CFM for the unit by changing the speed tap of the
indoor blower motor at the heat or cool tap on the control
board connection with the one of the speed taps on “M1”
or “M2” (Black-High Speed, Blue-Medium Speed, Red-Low
Speed).
eem mOtOr
Adjust the CFM for the unit by changing the position of the
low voltage leads on the motor terminal block. Green is for
Fan Only. Yellow is for Cooling and Heat Pump Heating. Re-
fer to Appendix A for blower performance at each speed tap.
NOTE: If more than one lead is energized simultaneously,
the motor will run at the higher speed.
set evaPOratOr fan rPm
Actual RPM’s must be set and veried with a tachometer
or strobe light. Refer to Appendices for basic unit fan RPM.
Refer also to “Airow” section of this manual. With discon-
nect switch open, disconnect thermostat wires from termi-
nals Y and W. This will prevent heating and mechanical cool-
ing from coming on. Place a jumper wire across terminals
R and G at TB1 terminal block. Close disconnect switch;
evaporator fan motor will operate so RPM can be checked.
For gas heat units, the airow must be adjusted so that the
air temperature rise falls within the ranges given stated on
Data Plate (see Appendix A - Blower Performance).

16
evaPOratOr fan rOtatiOn check (three Phase mOdels Only)
Check that fan rotates clockwise when viewed from the drive
side of unit and in accordance with rotation arrow shown
on blower housing. If it does not, reverse any two incoming
power cables at Single Point Power Block. In this case, re-
peat bearing check.
Do not attempt to change load side wiring. Internal wiring
assures all motors and compressors will rotate in correct di-
rection once evaporator fan motor rotation check has been
made.
electrical inPut check
Make preliminary check of evaporator fan ampere draw and
verify that motor nameplate amps are not exceeded. A nal
check of amp draw should be made upon completion of air
balancing of the duct system (see Appendix B).
BELT DRIVE MODELS ONLY
The drive on the supply fan is typically set in the middle
of the RPM range. The drive motor sheave pitch diameter
is eld adjustable for the required airow. Refer to “Motor
Sheave Adjustments” section.
Upon completion of the air ow balancing, we recommend
replacing the variable pitched motor sheave with a proper-
ly-sized xed sheave. A matching xed sheave will provide
longer belt and bearing life and vibration free operation. Ini-
tially, it is best to have a variable pitched motor sheave for
the purpose of airow balancing, but once the balance has
been achieved, xed sheaves maintain alignment and min-
imize vibration more effectively. For direct drive units, move
fan speed wire.
bearing check
Prior to energizing any fans, check and make sure that all set-
screws are tight so that bearings are properly secured to shafts.
tensiOn and alignment adjustment
Correct belt tension is very important to the life of your belt.
Too loose a belt will shorten its life; too tight, premature mo-
tor and bearing failure will occur. Check you belt drive for ad-
equate “run-in” belt tension by measuring the force required
to deect the belt at the midpoint of the span length. Belt
tension force can be measured using a belt tension gauge,
available through most belt drive manufacturers.
SPANLENGTHt
*DEFLECTION
FORCE
h
C
d H
D
*Apply force to the center of the span.
Belt Tension Adjustment
t = Span length, inches
C = Center distance, inches
D = Larger sheave diameter, inches
d = Smaller sheave diameter, inches
h = Deection height, inches
BELT DRIVE USED NEW
AX Standard 3.0 to 4.0 4.2 ± 0.5 5.5 ± 0.5 0.313
DEFLECTION
FORCE (lbs)
TYPE
DEFLECTION
(in)
SMALL
SHEAVE
DIAMETER
(in)
Recommended Pounds of Force Per Belt
New V-belts will drop rapidly during the rst few hours of
use. Check tension frequently during the rst 24 hours of op-
eration. Tension should fall between the minimum and maxi-
mum force. To determine the deection distance from a nor-
mal position, measure the distance from sheave to sheave
using a straightedge or a cord. This is your reference line.
On multiple belt drives, an adjacent undeected belt can be
used as a reference.
MOTOR SHEAVE ADJUSTMENTS
vl, vm, & 2vP variable Pitch key tyPe mOtOr sheaves
The driving and driven motor sheaves should be in align-
ment with each other and the shafts parallel.
vl& vmsheaves adjustment
1. Loosen set screw “B” using a 5/32” Allen key.
2. Making half or full turns from closed position, adjust
sheave pitch diameter for desired speed. DO NOT OPEN
MORE THAN FIVE FULL TURNS.
3. Tighten set screw “B” securely over at.
4. Carefully put on belts and adjust belt tension. DO NOT
FORCE BELTS OVER GROOVES.
5. Ensure all keys are in place and the set screws tight be-
fore starting drive. Recheck set screws and belt tension
after 24 hours service.
NOTE: Future adjustments should be made by loosening
the belt tension and increasing or decreasing the pitch diam-
eter of the sheave by half or full turns as required. Readjust
belt tension before starting drive.

17
NOTE: Except during brief periods when gas pressures are
being measured by qualied service personnel, the furnace
access panel must always be secured in place when the fur-
nace is in operation. An inspection port in the access panel
is provided to monitor the ame.
The rst step in checking out the gas-red furnace is to test
the gas supply piping to the unit for tightness and purge the
system of air using methods outlined in the latest edition of
the National Fuel Gas Code ANSI Z223.1. Verify that the
disconnect switch is in the “OFF” position. A soapy water
solution should be used to check for gas leaks. Since the
unit is subject to considerable jarring during shipment, it is
extremely important that all gas connections and joints be
tested for tightness. Gas piping downstream from the unit
inlet should be checked for leaks during the subsequent se-
quence check.
The supply gas pressure should be adjusted to 7.0” w.c. on
natural gas and 11.0” on LP gas with the gas burners oper-
ating. If there is more than one unit on a common gas line,
the pressures should be checked with all units under full re.
A supply pressure tap is provided on the upstream side of
the gas valve. A manifold pressure tap is provided on the
gas valve. The normal manifold pressure for full input is 3.5”
w.c. on natural gas and 9.5” w.c. for propane gas. Low re
natural gas 2.0” w.c., 6.0” low re propane gas. Minimum
gas supply pressure is 5.5” w.c. for natural gas and 11.0” for
propane gas. In order to obtain rating, gas supply pressure
must be 11.0” w.c. for propane gas.
The pressure regulator on LP gas models is adjusted for 9.5”
w.c. manifold pressure and is intended to prevent over-r-
ing only. Do not attempt adjustment of the built-in pressure
regulator unless the supply pressure is at least 7.0” w.c. on
natural gas or 13.0” w.c. on propane gas. Check the location
of the ignition electrode and the ame sensor for correct
gap setting.
FLAME
SENSOR
Flame Sensor and Ignition Electrode Location
C
B
VL & VM
NOTE: Do NOT operate sheave with ange projecting be-
yond the hub end.
GAS SYSTEM CHECK
Pre-Operation Checks
1. Close the manual gas valve external to the unit.
2. Turn off the electrical power supply to the unit.
3. Set the room thermostat to its lowest possible setting.
4. Remove the heat exchanger door on the side of the unit
by removing screws.
5. This unit is equipped with an ignition device which auto-
matically lights the main burner. DO NOT try to light burn-
er by any other method.
6. Move the gas control valve switch to the OFF position. Do
not force.
7. Wait ve minutes to clear out any gas.
8. Smell for gas, including near the ground. This is important
because some types of gas are heavier than air. If you
have waited ve minutes and you do smell gas, imme-
diately follow the warnings on page 3 of this manual. If
having waited for ve minutes and no gas smell is noted,
move the gas control valve switch to the ON position.
9. Replace the heat exchanger door on the side of the unit.
10. Open the manual gas valve external to the unit.
11. Turn on the electrical power supply to the unit.
12. Set the thermostat to desired setting.
gas suPPly Pressures & regulatOr adjustments
S HOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT
OFF , TURN OFF THE MANUAL GAS SHUTOFF VALVE EXTERNAL TO THE
UNIT BEFORE TURNING OFF THE ELECTRICAL SUPPLY .
WARNING
T O
AVOID PROPERTY DAMAGE , PERSONAL INJURY OR DEATH , DO
NOT FIRE GAS UNIT WITH FLUE BOX COVER REMOVED .
WARNING

18
NATURALGAS
(Dia)
PROPANE (LP)
(Dia)
45,000 223,000 #43 #55
70,000 323,000 #43 #55
92,000 423,000 #43 #55
115,000 523,000 #43 #55
140,000 623,000 #43 #55
GAS ORIFICES
MAXIMUM
INPUT
(BTUH)
NUMBER
OF
BURNERS
MAXIMUM
BTUH/BURNER
Heat Exchanger and Burner Orice Specications
NOTE: Gas appliances located more than 2000 feet above
sea level must be derated 4% per 1000 feet of total ele-
vation and that variance in gas heating value and specic
gravity require change in manifold pressure to obtain rating,
it is mandatory that the input be adjusted at the installation
site. All installations should be made as outlined in the lat-
est edition of the National Fuel Gas Code ANSI Z223.1,sec-
tion “Procedures To Be Followed To Place An Appliance in
Operation”. Refer also to the “User’s Information Manual”
supplied with the unit for additional information on the gas
furnace.
Gas Supply And Manifold Check
Gas supply pressure and manifold pressure with the burners
operating must be as specied on the rating plate.
Gas Inlet Pressure Check
Gas inlet pressure must be checked and adjusted in accor-
dance to the type of fuel being consumed.
With Power And Gas Off:
1. Connect a water manometer or adequate gauge to the
inlet pressure tap of the gas valve.
Inlet gas pressure can also be measured by removing the
cap from the dripleg and installing a predrilled cap with a
hose tting.
With Power And Gas On:
2. Put unit into heating cycle and turn on all other gas con-
suming appliances.
NATURAL Min. 5.0" W.C., Max. 10.0" W.C.
PROPANE Min. 11.0" W.C., Max. 14.0" W.C.
INLET GAS PRESSURE
NOTE: Inlet Gas Pressure Must Not Exceed the Maximum
Value Shown.
If operating pressures differ from above, make necessary
pressure regulator adjustments, check piping size, etc., and/
or consult with local utility.
Manifold Pressure Check
The gas valve has a tapped opening to facilitate measure-
ment of the manifold pressure. A “U” Tube manometer hav-
ing a scale range from 0 to 12 inches of water should be
used for this measurement. The manifold pressure must be
measured with the burners operating.
1. With disconnect switch open, remove eld connected
thermostat wire from terminal R, W1 and W2 on TB1.
Place jumper wire between R, W1 and W2 to engage
high stage heat. (note on 045 kbtu/hr units W2 is not
used, only jumper R to W1).
2. See Figure in input rating section for gas valve adjust-
ment.
To adjust the pressure regulator, remove the adjustment
screw or cover on the gas valve. Turn out (counterclock-
wise) to decrease pressure, turn in (clockwise) to increase
pressure. Only small variations in gas ow should be made
by means of the pressure regulator adjustment. In no case
should the nal manifold pressure vary more than plus or
minus 0.3 inches water column from the specied nominal
pressure. Any major changes in ow should be made by
changing the size of the burner orices. The measured in-
put rate to the furnace must not exceed the rating specied
on the unit rating plate.
For natural gas, the high stage manifold pressure must be
between 3.2 and 3.8 inches water column (3.5 nominal).
Low stage manifold pressure must be between 1.7 to 2.3
inches water column (2.0 nominal).
3. To set low re rate on 090, 115 and 140 kbtu/hr: Open
disconnect switch, and remove jumper from R to W2. To
set low re manifold pressure, repeat steps above. Refer
to Figure in input rating section for location of high and
low stage adjustment.
For propane gas, the manifold pressure must be between
9.7 and 10.3 inches water column (10.0 nominal). Low stage
manifold must be between 5.7 and 6.3 inches water column
(6.0 nominal).
Gas Input (Natural Gas Only) Check
It is the responsibility of the contractor to adjust the gas input
to the unit.
To measure the gas input use a gas meter and proceed as
follows:
1. Turn off gas supply to all other appliances except the unit.
2. With the unit operating, time the smallest dial on the me-
ter for one complete revolution. If this is a 2 cubic foot dial,
divide the seconds by 2; if it is a 1 cubic foot dial, use the
seconds as is. This gives the seconds per cubic foot of
gas being delivered to the unit.
3. INPUT=GAS HTG VALUE x 3600 / SEC. PER CUBIC
FOOT
Example: Natural gas with a heating value of 1000 BTU per
cubic foot and 34 seconds per cubic foot as determined by
Step 2, then:
Input = 1000 x 3600 / 34 = 106,000 BTU per Hour. NOTE:
BTU content of the gas should be obtained from the gas
supplier. This measured input must not be greater than
shown on the unit rating plate.
Adjust input rate by varying the adjustment of the gas pres-
sure regulator on the gas valve. All adjustments must be
made with furnace operating at high re and at normal oper-

19
ating temperature. A manometer should be connected to the
gas valve to verify pressure is within the specied range (see
following gures for manometer connections). Clockwise
rotation of the pressure regulator screw increases pressure
and gas ow rate. Turn screw counterclockwise to decrease
pressure and gas ow rate. After adjustment the furnace
temperature rise must be within the range specied on the
unit data plate. NOTE: Thermal efciency of the furnace is a
product efciency rating determined under continuous oper-
ating conditions independent of any installed system.
Pressure Regulator
Adjustment
(Under Cap Screw)
Gas Valve
On/Off
Selector
Switch
INLET OUTLET
Inlet Pressure
Ta p
Outlet Pressure
Ta p
White-Rodgers 36G22 - Single Stage
Inlet
Pressure Boss
Low Fire
Regulator Adjust
Manometer
Manometer
Hose
High Fire Regulator
Adjust Regulator
Vent
Outlet
Pressure Boss
Open to
Atmosphere
White-Rodgers 36G54 (2-Stage) Connected to Manometer
Pressure Adjustments
To connect manometer to gas valve:
1. Back outlet pressure test screw (inlet/outlet pressure
boss) out one turn (counterclockwise, not more than one
turn).
2. Attach a hose and manometer to the outlet pressure boss
of the valve.
To remove manometer from gas valve:
1. Remove manometer hose from outlet pressure boss.
2. Turn outlet pressure test screw in to seal pressure port
(clockwise, 7 in-lb. minimum).
3. Turn on electrical power and gas supply to the system.
4. Turn on system power and energize valve.
5. Using a leak detection solution or soap suds, check for
leaks at pressure boss screw. Bubbles forming indicate a
leak. SHUT OFF GAS AND FIX ALL LEAKS IMMEDIATE-
LY.
T O PREVENT UNRELIABLE OPERATION OR EQUIPMENT DAMAGE , THE
GAS MANIFOLD PRESSURE MUST BE AS SPECIFIED ON THE UNIT
RATING PLATE . O NLY MINOR ADJUSTMENTS SHOULD BE MADE BY
ADJUSTING THE GAS VALVE PRESSURE REGULATOR .
CAUTION
6. Relight all other appliances turned off in step 1. Be sure all
pilot burners are operating.
Main Burner Flame Check
Flames should be stable, soft and blue (dust may cause or-
ange tips but they must not be yellow) and extending directly
outward from the burner without curling, oating or lifting off.
NOx Screen Check
Verify that the alignment of the NOx screens is at 6 o’ clock.
In jurisdictions that do not require low NOx emissions, NOx
screens may be removed.
Temperature Rise Check
Check the temperature rise through the unit by placing ther-
mometers in supply and return air registers as close to the
unit as possible. Thermometers must not be able to sample
temperature directly from the unit heat exchangers, or false
readings could be obtained.
1. All registers must be open; all duct dampers must be in their
nal (fully or partially open) position and the unit operated
for 15 minutes before taking readings.
2. The temperature rise must be within the range specied on
the rating plate.
NOTE: Air temperature rise is the temperature difference
between supply and return air.
With a properly designed system, the proper amount of tem-
perature rise will normally be obtained when the unit is op-
erated at rated input with the recommended blower speed.
If the correct amount of temperature rise is not obtained, it
may be necessary to change the blower speed. A higher
blower speed will lower the temperature rise. A slower blow-
er speed will increase the temperature rise.
NOTE: Blower speed MUST be set to give the correct air
temperature rise through the unit as marked on the rating
plate.
NORMAL SEQUENCE OF OPERATION
heating
This unit has one (RS) Manual Reset Limit Control Switch.
Check the limit to make sure it has not tripped. The limit may
arrive at the job site tripped as a result of shipping shock.

20
If the venter motor comes on, but the unit does not attempt
ignition, check if the ALS (Auxiliary High Limit Control Switch)
requires resetting.
1. With electricity and gas turned on, the system switch in
the “HEAT” or “AUTO” position and the fan switch in the
“AUTO” position, the thermostat will close the circuit be-
tween unit terminals R and W (R-W) when the tempera-
ture falls below the thermostat setting.
2. D1 on IIC energizes relay IDMR.
3. Relay IDMR energizes the venter motor IDM.
4. Operation of the venter motor closes the pressure switch
PS located in the burner compartment. Unless exces-
sive temperatures or shipping shock have opened high
limit control ALS, power is fed to the integrated ignition
control, which then initiates a 15-second pre-purge time
delay. During this period, the venter motor will clear the
combustion chamber of any residual gas.
5. After the pre-purge period, the ignition control energizes
the Wl-C gas valve and simultaneously initiates a “three
(3)-try” spark ignition sequence.
6. When the burners are ignited, a minimum one (1) mi-
cro-amp DC current will ow through the ame between
the sensor electrode and the grounded burner.
7. When the controller proves that the ame has been es-
tablished, it will keep the gas valve energized and
discontinue the ignition spark. High stage manifold pres-
sure will be approximately 3.5” w.c. for natural gas and
10.0” w.c. for propane (LP). Low re natural gas is 2.0”
w.c.; low re propane 6.0” w.c.
8. If the control is unable to ignite the burners after its initial
attempt, it will initiate another purge and spark sequence.
A third purge and spark sequence will be initiated if the
second attempt is unsuccessful. If the third attempt is
unsuccessful, the controller will close the gas valve and
lock itself out. It may be reset by momentarily interrupting
power. This may be accomplished by briey lowering the
room thermostat set-point below room temperature, or by
shutting off the main power to the unit. (See TP-105 for
more details.)
9. Integrated ignition control will close its normally open
contacts after a delay of approximately 30 seconds. This
action energizes contactor BC and starts the supply fan
motor. Operation of the supply fan circulates air across
the heat exchanger and delivers heated air to the condi-
tioned space.
10. When the space temperature rises, the thermostat will
open R-W. Opening R-W will cause the gas valve to
close, and the furnace to shut down.
11. The furnace has three high temperature limit controls,
which can shut down the burner. They do not shut down
the venter motor.
Unit Shutdown
1. Set the thermostat to lowest setting.
2. Turn off the electrical power supply to the unit.
3. Remove the heat exchanger door on the side of the unit
by removing screws.
4. Move the gas control valve switch to the OFF position. Do
not force.
5. Close manual gas shut off valve external to the unit.
6. Replace the heat exchanger door on the unit.
7. If cooling and/or air circulation will be desired, turn ON
the electrical power.
autOmatic reset high limit cOntrOl (ls)
Located in the burner compartment on the heat exchang-
er, its sensing element projects through the blower section
bulkhead and senses the temperature at the rear of the fur-
nace. It will cycle the furnace off if the temperature exceeds
100°F plus maximum rise.
auxiliary high limit cOntrOl (als)
Located in the blower compartment on the blower housing, it
senses air temperature within the blower compartment and
protects the lters from excessive temperature. It will shut
down the furnace if it senses excessive temperatures.
Elevated temperatures at the control are normally caused by
blower failure. The reason for the opening should be deter-
mined and repaired prior to resetting.
manual reset flame rOllOut cOntrOl (rs)
Located in the burner compartment at the top of the burn-
er assembly, it senses high temperature that could occur if
the heat exchanger tubes were plugged and the ame was
rolling out instead of entering the tubes. It has a manual
push-button reset that cannot be actuated until the limit con-
trol has cooled.
The reason for elevated temperatures at the control should
be determined and repaired prior to resetting this manual
reset control.
WARNING
T
O AVOID PROPERTY DAMAGE, PERSONAL INJURY OR DEATH DUE TO FIRE
OR EXPLOSION, A QUALIFIED SERVICER MUST INVESTIGATE THE REASON FOR
THE ROLLOUT PROTECTION DEVICE TO OPEN BEFORE MANUALLY RESETTING
THE ROLLOUT PROTECTION DEVICE.
refrigeratiOn system checks
This unit is equipped with a piston type metering device or
non-adjustable TXV.
Ensure the hold-down bolts on the compressor are secure
and have not vibrated loose during shipment. Check that the
vibration grommets have been installed and visually check
all piping for damage and leaks and repair if necessary. The
entire system has been factory charged and tested, making
it unnecessary to eld charge. Factory refrigerant charge is
shown on the unit’s nameplate.
To conrm charge levels or, if a leak occurs and charge
needs to be added to the system, it is recommended to
evacuate the system and recharge refrigerant to the unit’s
nameplate specications. This unit has been rated in the
cooling mode at the AHRI rated conditions of: indoor (80°F
db/67°F wb) and outdoor (95°F db). While operating at this