McQuay MPS003AG Installation Manual
© 2007 McQuay International
Maverick I™
Commercial Packaged Rooftop System
Heating & Cooling
Gas/Electric
Models MPS003AG – 005AG
3 to 5 Tons
Installat
ion and Ma
intenance Manual
IM 860
Group: Applied Systems
Part Number: 92-102421-02-00
Date: March 2007
ARI Standard
210/240 UAC
™
2 IM 860
Table of Contents
Table of Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Checking Product Received . . . . . . . . . . . . . . . . . . . . 3
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Major Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Unit Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pre-Installation Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Location Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Outside Slab Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Attaching Exhaust and Combustion Air Inlet Hoods. . . . . . . . . . . 7
Cover Panel Installation/Conversion Procedure. . . . . . . . . . . . . . 7
Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Rooftop Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Return Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Gas Supply, Condensate Drain and Piping . . . . . . . 10
Gas Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
LP Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
NOx Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Adjusting or Checking Furnace Input . . . . . . . . . . . . . . . . . . . . . 11
Condensate Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Hook Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Furnace Section Controls and Ignition System . . . 14
Normal Furnace Operating Sequence . . . . . . . . . . . . . . . . . . . . 14
Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Burners. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Manual Reset Overtemperature Control . . . . . . . . . . . . . . . . . . 15
Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Limit Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
System Operating Information . . . . . . . . . . . . . . . . . 16
Advise The Customer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Furnace Section Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Cooling Section Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Replacement Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Wiring Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Charging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Blower Motor Speed Taps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
General Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-23
Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Airflow Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-28
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29-32
Charge Charts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33-35
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36-38
Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Introduction
This manual contains the installation and operating instructions for your packaged rooftop unit. There are some precautions that should be taken to derive maximum satisfaction
from it. Improper installation can result in unsatisfactory operation or dangerous conditions.
Read this manual and any instructions packaged with separate
equipment required to make up the system prior to installation.
Give this manual to the owner and explain its provisions. The
owner should retain this manual for future reference.
Checking Product Received
Upon receiving the unit, inspect it for any damage from shipment. Claims for damage, either shipping or concealed, should
be filed immediately with the shipping company. IMPORTANT: Check the unit model number, heating size, electrical
characteristics, and accessories to determine if they are correct.
Specifications
General
The Combination Gas Heating/Electric Cooling Rooftop is
available in 80,000, 100,000, 120,000 and 135,000 BTU/Hr.
heating inputs and cooling capacities of 3, 4, and 5 nominal
tons of cooling. Units are convertible from bottom supply and
return to side supply and return by relocation of supply and
return air access panels. See cover installation detail.
The units are weatherized for mounting outside of the building.
The information on the rating plate is in compliance with the
FTC and DOE rating for single phase units. The following
information is for three phase units which are not covered
under the DOE certification program.
1 The energy consumption of the ignition system used with
this unit is 9 watts.
2 The efficiency rating of this unit is a product thermal effi-
ciency rating determined under continuous operating conditions independent of any installed system.
Major Components
The unit includes a hermetically-sealed refrigerating system
(consisting of a scroll compressor, condenser coil, evaporator
coil with capillary tube assembly), a circulation air blower, a
condenser fan, a heat exchanger assembly, gas burner and control assembly, combustion air motor and fan, and all necessary
internal electrical wiring. The cooling system of these units is
factory-evacuated, charged and performance tested.
Refrigerant amount and type are indicated on rating plate.
Safety Information
The manufacturer’s warranty does not cover any damage or
defect to the air conditioner caused by the attachment or
use of any components, accessories or devices (other than
those authorized by the manufacturer) into, onto or in conjunction with the air conditioner. you should be aware that
the use of unauthorized components, accessories or
devices may adversely affect the operation of the air conditioner and may also endanger life and property. the manufacturer disclaims any responsibility for such loss or injury
resulting from the use of such unauthorized components,
accessories or devices.
IM 860
3
Recognize this symbol as an indication of
Important Safety Information!
Units are not design certified to be installed inside the structure. Doing so can cause inadequate unit performance as
well as property damage and carbon monoxide poisoning
resulting in personal injury or death.
Install this unit only in a location and position as specified in
the location requirements and considerations section of
these instructions. Provide adequate combustion and ventilation air to the unit space as specified in the venting section
of these instructions.
Provide adequate combustion and ventilation air to the unit
space as specified in the combustion and ventilation air section of these instructions.
Use only with type of gas approved for this unit. Refer to the
unit rating plate.
Combustion products must be discharged outdoors.
Connect this unit to an approved vent system only, as specified in Vent Pipe Installation section of these instructions.
Never test for gas leaks with an open flame. It can cause an
explosion or fire resulting in property damage, personal
injury or death. Use a commercially available soap solution
made specifically for the detection of leaks to check all connections, as specified in the Gas Supply and Piping section
of these instructions.
Always install unit to operate within the unit's intended temperature-rise range with a duct system which has an external static pressure within the allowable range, as specified
in ducting section of these instructions. See also unit rating
plate.
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DANGER
!
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WARNING
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WARNING
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WARNING
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DANGER
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4
Figure 1: Bottom View
Figure 2: Cabinet Dimensions and Access Locations
Unit Dimensions
FOR CLEARANCES
SEE FIGURE 7.
IMPORTANT: THIS
UNIT MUST BE
MOUNTED LEVEL
IN BOTH DIRECTIONS TO ALLOW
WATER TO DRAIN
FROM THE CONDENSER SECTION
AND CONDENSATE PAN.
I316
I281
IM 860
2
9.56
44.125
48.125
4.5
2.25
SUPPLY AIR
RETURN AIR
2
3.25
4.5
20
20
13.125
13.125
14.44
2
31.19
3.81
78.25
24.03
48.06
5.34
BLOWER
ACCESS
COIL/FILTER
ACCESS
SUPPLY COVER
RETURN COVER
4.625
5
Figure 3: Cabinet Dimensions and Access Locations
Figure 4: Supply and Return Dimensions – Back View
I282
I288
IM 860
48.5
24.25
7.22
75.53
11.125
12.25
12.25
35
6.84
4.94
13.72
76.25
5.5
19.125
19.125
35
18
9.19
6 IM 860
Installation
General
Install this unit in accordance with The American National
Standard Z223.1-latest edition manual entitled “National Fuel
Gas Code,” and the requirements or codes of the local utility
or other authority having jurisdiction.
Additional helpful publications available from the “National
Fire Protection Association” are: NFPA-90A - Installation of
Air Conditioning and Ventilating Systems 1985 or latest edition. NFPA-90B - Warm Air Heating and Air Conditioning
Systems 1984.
These publications are available from:
National Fire Protection Association, Inc.
Batterymarch Park
Quincy, MA 02269
1 PRE-INSTALLATION CHECK-POINTS — Before
attempting any installation, carefully consider the following points:
Structural strength of supporting members
(Rooftop Installation)
Clearances and provision for servicing
Power supply and wiring
Gas supply and piping
Air duct connections and sizing
Drain facilities and connections
Location for minimum noise and
vibration - away from bedroom
windows
2 LOCATION CONSIDERATIONS
The metal parts of this unit may be subject to rust or deterioration in adverse environmental conditions. This oxidation could shorten the equipment’s useful life. Salt spray,
fog or mist in seacoast areas, sulphur or chlorine from
lawn watering systems, and various chemical contaminants from industries such as paper mills and petroleum
refineries are especially corrosive.
If the unit is to be installed in an area where contaminants are likely to be a problem, give special attention
to the equipment location and exposure.
1 Avoid having lawn sprinkler heads spray directly on
the unit cabinet.
2 In coastal areas locate the unit on the side of the build-
ing away from the waterfront.
3 Shielding by a fence or shrubs may give some protec-
tion.
1 Frequent washing of the cabinet, fan blade and coil with
fresh water will remove most of the salt or other contaminants that build up on the unit.
2 Regular cleaning and waxing of the cabinet with a good
automobile polish will provide some protection.
3 A good liquid cleaner may be used several times a year to
remove matter that will not wash off with water.
Several different types of protective coatings are offered in
some areas. These coatings may provide some benefit, but the
effectiveness of such coating materials cannot be verified by
the equipment manufacturer.
The best protection is frequent cleaning, maintenance and
minimal exposure to contaminants.
Outside Slab Installation
(Typical outdoor slab installation is shown in Figure 5.)
1 Select a location where external water drainage cannot
collect around unit.
2 Provide a level slab sufficiently high enough above grade
to prevent surface water from entering the unit
3 The location of the unit should be such as to provide
proper access for inspection and servicing as shown in
Figure 7.
4 Locate unit where operating sounds will not disturb
owner or neighbors.
This unit may be used to heat the building or structure during construction if the following installation requirements are
met. Installation must comply with all installation instructions
including:
• Proper vent installation;
• Furnace operating under thermostatic control;
• Return air duct sealed to the furnace;
• Air filters in place;
• Set furnace input rate and temperature rise per rating
plate marking;
• Means of providing outdoor air required for combustion;
• Return air temperature maintained between 55°F (13°C)
and 80°F (27°C); and
• Installation of exhaust and combustion air inlet hoods
completed;
• Clean furnace, duct work and components upon substantial completion of the construction process, and verify furnace operating conditions including ignition, input rate,
temperature rise and venting, according to the instructions.
These units are designed certified for outdoor installation
only. Installation inside any part of a structure can result in
inadequate unit performance as well as property damage.
Installation inside can also cause recirculation of flue products into the conditioned space resulting in personal injury
or death.
When a unit is installed so that supply ducts carry air circulated by the unit to areas outside the space containing the
unit, the return air shall also be handled by duct(s) sealed to
the unit casing and terminating outside the space containing
the unit.
Power supply to unit must be disconnected before making
field connections. To avoid electrical shock, personal injury
or death, be sure to rigorously adhere to field wiring procedures regarding proper lockout and tagout of components.
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WARNING
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DANGER
!
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WARNING
!
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DANGER
!
5 Locate unit so roof runoff water does not pour directly on
the unit. Provide gutter or other shielding at roof level.
Do not locate unit in an area where excessive snow drifting may occur or accumulate.
6 Where snowfall is anticipated, the height of the unit
above the ground level must be considered. Mount unit
high enough to be above anticipated maximum area
snowfall and to allow combustion air to enter the combustion air inlet.
7 Select an area which will keep the areas of the vent, air
intake, and A/C condenser fins free and clear of obstructions such as weeds, shrubs, vines, snow, etc. Inform the
user accordingly.
8 Remove compressor shipping supports (if so equipped)
after installation.
Attaching Exhaust and Combustion Air
Inlet Hoods
IMPORTANT: Do not operate this unit without the exhaust/combus-
tion air inlet hood properly installed. This hood is shipped in a carton
in the blower compartment inside the unit and must be attached
when the unit is installed. See Figure 3.
To attach exhaust/combustion air inlet hood:
1 Remove screws securing blower access panel and remove
access panel. For location of blower access panel, see Figure
2.
2 Remove exhaust/combustion air inlet hood from the carton,
located inside the blower compartment.
3 Attach blower access panel.
4 Attach the combustion air inlet/exhaust hood with screws.
Reference Figure 3 for proper location. Screws are in carton
with the hood.
5 Vent the unit using the flue exhaust hood, as supplied from
the factory, without alteration or addition.
Cover Panel Installation/Conversion
Procedure
Downflow To Horizontal
1 Remove the screws and covers from the outside of the
supply and return sections.
2 Install the covers in the bottom supply and return open-
ings with the painted side up. See Figure 6. Use the existing gasket to seal the covers.
3 Secure the supply cover to the base of the unit with 1
screw, engaging prepunched tab in unit base.
4 Secure the return cover to the base of the unit with screws
engaging prepunched holes in the unit base.
This unit is provided with 2 - 25” X 16” X 1” disposable filters. When replacing filters, ensure they are inserted fully to
the back to prevent bypass.
Clearances
The following minimum clearances must be observed for proper unit performance and serviceability. Reference Figure 7.
NOTE: Supply duct may be installed with 0 inch clearance to
combustible materials, provided 1 inch minimum Fiberglass insulation is applied either inside or on the outside of the duct.
Rooftop Installation
1 Before locating the unit on the roof, make sure that the
roof structure is adequate to support the weight involved.
(See Electrical & Physical Tables in this manual.) THIS
IS VERY IMPORTANT AND THE INSTALLER’S
RESPONSIBILITY.
2 For rigging and roofcurb details, see Figures 9, 10 and 11.
3 The location of the unit on the roof should be such as to
provide proper access for inspection and servicing.
IM 860
7
Figure 6: Cover gasket detail for units shipped for downflow application being converted to horizontal
I631
Recommended
Clearance
Location
48ⴖ A - Front
18ⴖ B - Condenser Coil
12ⴖ* C - Duct Side
36ⴖ D - Evaporator End
60ⴖ E - Above
*Without Economizer. 57 With Economizer
Figure 5: Outside Slab Installation. Closet Distribution System. Slab
Floor Construction.
I298
8 IM 860
4 Remove compressor shipping supports (if so equipped)
after installation.
IMPORTANT: If unit will not be put into service immediately,
block off supply and return air openings to prevent excessive
condensation.
Ductwork
The installing contractor should fabricate ductwork in accordance with local codes. Use industry manuals as a guide when
sizing and designing the duct system. Contact Air
Conditioning Contractors of America, 1513 16th St. N.W.,
Washington, D.C. 20036.
Place the unit as close to the conditioned space as possible
allowing clearances as indicated. Run ducts as directly as possible to supply and return outlets. Use of non-flammable
weatherproof flexible connectors on both supply and return
connections at unit to reduce noise transmission is recommended.
On ductwork exposed to outside temperature and humidity,
use a minimum of 2ⴖ of insulation and a vapor barrier.
Distribution system in attic, furred space or crawl space
should be insulated with at least 2ⴖ of insulation.
1
⁄2ⴖ to 1ⴖ thick
insulation is usually sufficient for ductwork inside the air conditioned space.
Provide balancing dampers for each branch duct in the supply
system. Properly support ductwork from the structure.
IMPORTANT: In the event that the return air ducts must be run
through an “unconfined” space containing other fuel burning
equipment, it is imperative that the user be informed against
future changes in construction which might change this to a “confined space.” Also, caution the user/homeowner against any
future installation of additional equipment (such as power ventilators, clothes dryers, etc., within the existing unconfined and/or
confined space which might create a negative pressure within
the vicinity of other solid, liquid, or gas fueled units.
Return Air
Figure 7: Clearances
I297
Do not, under any circumstances, connect return ductwork
to any other heat producing device such as fireplace insert,
stove, etc. Unauthorized use of such devices may result in
fire, carbon monoxide poisoning, explosion, personal injury,
property damage or death.
▲▲
DANGER
!
Never allow products of combustion or the flue products to
enter the return air ductwork, or the circulating air supply. All
return ductwork must be adequately sealed and secured to
the furnace with sheet metal screws, and joints taped. All
other duct joints must be secured with approved connections and sealed airtight.
Failure to prevent products of combustion from being circulated into the living space can create potentially hazardous
conditions, including carbon monoxide poisoning that could
result in personal injury or death.
Figure 8: Flat rooftop installation, attic or drop ceiling distributing system. Mounted on roofcurb. Curb must be
level.
I299
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DANGER
!
IM 860
9
N
A
*
E
T
D
Figure 11: Roofcurb
Figure 10: Roofcurb
RETURN DUCT*
SUPPLY DUCT*
NAILING STRIP
INSULATION PANELS
(2) SUPPLIED
GASKET
(FULL PERIMETER
AND ON DIVIDERS,
MUST BE ABOVE DUCT
AND INSULATION
PANEL FLANGES.)
HOLD
DOWN
BRACKET
TYP. (4) PLCS.
UNIT
I296
ST-A0801-19-01
CORNER WEIGHTS BY PERCENTAGE
AB C D
22% 27% 23%28%
SPREADER BAR
A
B
D
C
LIFTING BEAM
CABLE OR CHAIN
.625ⴖ SHACKLE
(EACH CORNER)
38.25
25.75
C.G.
ST-A0801-19-01
ROOFTOP UNIT
COUNTER FLASHING*
INSULATION*
CANT STRIP*
ROOF FELT*
INSULATION*
ROOF DECK*
*BY CONTRACTOR
ROOF
STRUCTURAL
MEMBER*
ROOFCURB
DUCT*
NAILER STRIP
GASKET
RETURN
SUPPLY
Figure 9: Rigging Detail
GASKET
NAILER STRIP
DUCT*
ROOFCURB
TURAL
ER*
ROOFTOP U
COUNTER FL
INSULATION
CANT STRIP*
ROOF F
INSULA
ROOF
10
Gas Supply, Condensate Drain
and Piping
Gas Connection
IMPORTANT: Connect this unit only to gas supplied by a com-
mercial utility.
1 Install gas piping in accordance with local codes and reg-
ulations of the local utility company. In the absence of
local codes, the installation must conform to the specifications of the National Fuel Gas Code, ANSI Z223.1 latest edition.
NOTE: The use of flexible gas connectors is not permitted.
2 Connect the gas line to the gas pipe inlet opening provid-
ed into the 1/2ⴖ inlet valve. See Figure 5 or 8 for typical
piping.
3 Size the gas line to the furnace adequate enough to pre-
vent undue pressure drop and never less than 1/2ⴖ.
4 Install a drip leg or sediment trap in the gas supply line as
close to the unit as possible.
5 Install an outside ground joint union to connect the gas
supply to the control assembly at the burner tray.
6 Gas valves have been factory installed. Install a manual
gas valve where local codes specify a shut-off valve outside the unit casing. (See Figure 12.)
NOTE: The Commonwealth of Massachusetts requires the gas
shut-off valve to be a T-handle gas lock.
7 Make sure piping is tight. A pipe compound resistant to
the action of liquefied petroleum gases must be used at
all threaded pipe connections.
8 IMPORTANT: any additions, changes or conversions
required for the furnace to satisfactorily meet the application should be made by a qualified installer, service
agency or the gas supplier, using factory-specified or
approved parts. In the commonwealth of Massachusetts,
installation must be performed by a licensed plumber or
gas fitter for appropriate fuel.
IMPORTANT: Disconnect the furnace and its individual shutoff
valve from the gas supply piping during any pressure testing of
that system at test pressures in excess of 1/2 pound per square
inch gauge or isolate the system from the gas supply piping system by closing its individual manual shutoff valve during any
pressure testing of this gas supply system at pressures equal to
or less than 1/2 PSIG.
IMPORTANT: Check the rating plate to make certain the unit is
equipped to burn the type of gas supplied. Care should be taken
after installation of this equipment that the gas control valve not
be subjected to high gas supply line pressure.
In making gas connections, avoid strains as they may cause
noise and damage the controls. A backup wrench is required to
be used on the valve to avoid damage.
The capacities of gas pipe of different diameters and lengths in
cu. ft. per hr. with pressure drop of 0.3 in. and specific gravity
of 0.60 (natural gas) are shown in Table 1.
After determining the pipe length, select the pipe size which
will provide the minimum cubic feet per hour required for the
gas input rating of the furnace. By formula:
Gas Input of Furnace
(BTU/HR)
Cu. Ft. Per Hr. Required =
Heating Value of Gas
(BTU/FT3)
The gas input of the furnace is marked on the furnace rating
plate. The heating value of the gas (BTU/FT3) may be determined by consulting the local natural gas utility or the L.P. gas
supplier.
LP Conversion
IM 860
Never test for gas leaks with an open flame. It can cause an
explosion or fire resulting in property damage, personal
injury or death. Use a commercially available soap solution
made specifically for the detection of leaks to check all connections, as specified in the Gas Supply and Piping section
of these instructions.
Figure 12: Suggested Gas Piping
FROM GAS
METER
*
Factory supplied grommet must be utilized.
MANUAL GAS
SHUT-OFF
VALVE
UNIT GAS SUPPLY
CONNECTION
*
ROOF OR GROUND LEVEL INSTALLATION
Table 1: Gas Pipe Capacity Table (Cu. Ft./Hr.)
Nominal
Iron Pipe
Size,
Inches
Equivalent Length of Pipe, Feet
10 20 30 40 506070 80
1
⁄2 1329273 63 56 50 46 43
3
⁄4 278 190 152 130 115 105 96 90
1 520 350 285 245 215 195 180 170
11⁄4 1,050 730 590 500 440 400 370 350
11⁄2 1,600 1,100 890 760 670 610 560 530
Factory for use on natural gas only. Conversion to LP gas
requires a special kit supplied by the distributor or manufacturer. Mailing addresses are listed on the furnace rating plate,
parts list and warranty. Failure to use the proper conversion kit
can cause fire, carbon monoxide poisoning, explosion, personal injury, property damage or death.
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DANGER
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DANGER
!
11
Convert the valve to use liquefied petroleum (LP) gas by
replacing the pressure regulator spring with the conversion kit
spring. This LP kit spring allows the regulator to maintain the
proper manifold pressure for LP gas. The correct burner LP
orifices are included in the kit. See Figure 13.
IMPORTANT: To remove the gas valve, remove the four screws
securing the manifold pipe to the burner tray. Remove the manifold pipe with gas valve attached. See Figure 14.
NOTE: Order the correct LP conversion kit from the furnace
manufacturer. See Conversion Kit Index shipped with unit for
proper LP kit number. Furnace conversion to LP gas must be
performed by a qualified technician.
NOx Models
When converting units equipped with NOx inserts to LP gas,
the stainless steel screen mesh inserts in the entrance of the
tubular exchangers are not required to meet SCAQMD NOx
emission levels. These inserts and 1/8ⴖ diameter retaining rod
should be carefully removed before firing this furnace on LP
gas. IMPORTANT: This furnace is not designed to operate on
LP gas with the NOx inserts in place.
Step by step instructions on removing the NOx inserts and
retaining rod are included in the Conversion Kit Installation
Instructions.
Adjusting or Checking Furnace Input
– Natural Gas Line Pressure 5” - 10.5” W.C.
– LP Gas Line Pressure 11” - 13” W.C.
– Natural Gas Manifold Pressure 3.5” W.C
– LP Gas Manifold Pressure - 10” W.C.
Supply and manifold pressure taps are located on the gas valve
body 1/8” N.P.T. and on the manifold.
Use a properly calibrated manometer gauge for accurate gas
pressure readings.
Only small variations in the gas flow should be made by
means of the pressure regulator adjustment. Furnaces functioning on LP gas must be set by means of the tank or branch
supply regulators. The furnace manifold pressure should be set
at 10” W.C. at the gas control valve.
To adjust the pressure regulator, remove the regulator cap and
turn the adjustment screw clockwise to increase pressure or
counterclockwise to decrease pressure. Then replace the reg-
ulator cap securely.
Any necessary major changes in the gas flow rate should be
made by changing the size of the burner orifices. To change
orifice spuds, shut off the manual main gas valve and remove
the gas manifold.
For elevations up to 2,000 feet, rating plate input ratings apply.
For high altitudes (elevations over 2,000 ft.), see conversion kit
index 92-21519-XX for derating and orifice spud sizes.
Check of input is important to prevent over-firing of the
furnace beyond its design-rated input. NEVER SET
INPUT ABOVE THAT SHOWN ON THE RATING
PLATE. Use the following table or formula to determine
input rate.
Heating Value of Gas
(BTU/Cu. Ft.) x 3600
Cu. Ft. Per Hr. Required =
Time in Seconds
(for 1 Cu. Ft.) of Gas
Start the furnace and measure the time required to burn one
cubic foot of gas. Prior to checking the furnace input, make
certain that all other gas units are shut off, with the exception
of pilot burners. Time the meter with only the furnace in operation.
IM 860
Table 2: LP Gas Pipe Capacity Table (Cu. Ft./Hr.)
Maximum capacity of pipe in thousands of BTU per hour of undiluted liquefied petroleum
gases (at 11 inches water column inlet pressure).
(Based on a Pressure Drop of 0.5 Inch Water Column)
Nominal
Iron Pipe
Size, Inches
10 20 30 40 50 60 70 80 90 100 125 150
275 189 152 129 114 103 96 89 83 78 69 63
567 393 315 267 237 217 196 182 173 162 146 132
1,071 732 590 504 448 409 378 346 322 307 275 252
2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511
3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787
6,221 4,331 3,465 2,992 2,646 2,394 2,205 2,047 1,921 1,811 1,606 1,496
1/2
3/4
1
1-1/4
1-1/2
2
Length of Pipe, Feet
Example (LP): Input BTU requirement of unit, 150,000
Equivalent length of pipe, 60 ft. = 3/4ⴖ IPS required.
Figure 13
Figure 14
MANIFOLD PIPE
12
IMPORTANT NOTE FOR ALTITUDES ABOVE 2,000
FEET (610 METERS): The main burner orifices in your fur-
nace and in these kits are sized for the nameplate input and
intended for installations at elevations up to 2,000 feet in the
USA or Canada, or for elevations of 2,000 - 4,500 feet (610 1,373 meters) in Canada if the unit has been derated at the factory. For elevations above 2,000 feet (610 meters) IN THE
USA ONLY (see ANSI-Z223.1), the burner orifices must be
sized to reduce the input 4% for each 1,000 feet (305 meters)
above sea level.
NOTICE: DERATING OF THE HEATING INPUT FOR HIGH
ALTITUDE IN THE FIELD IS UNLAWFUL IN CANADA (REFER
TO CAN/CGA 2.17). UNITS INSTALLED IN ALTITUDES
GREATER THAN 2,000 FEET (610 METERS) MUST BE
SHIPPED FROM THE FACTORY OR FROM A FACTORY
AUTHORIZED CONVERSION STATION WITH THE HEATING
INPUT DERATED BY 10% SO AS TO OPERATE PROPERLY
IN ALTITUDES FROM 2,000 - 4,500 FEET (610 - 1,373
METERS).
Condensate Drain
The condensate drain connection of the evaporator is threaded
3/4ⴖ nominal P.V.C. pipe. IMPORTANT: Install a condensate
trap to ensure proper condensate drainage. See Figure 15.
Wiring
Power Supply
1 All wiring should be made in accordance with the
National Electrical Code. Consult the local power company to determine the availability of sufficient power to
operate the unit. Check the voltage at power supply to
make sure it corresponds to the unit’s RATED VOLTAGE REQUIREMENT. Install a branch circuit disconnect near the rooftop, in accordance with the N.E.C.,
C.E.C. or local codes. A bracket is provided with the unit
for mounting of the disconnect. See Figure 16.
2 It is important that proper electrical power is available at
the unit. Voltage should not vary more than 10% from
that stamped on the unit nameplate. On three phase units,
phases must be balanced within 3%.
3 For branch circuit wiring (main power supply to unit dis-
connect), the minimum wire size for the length of run can
be determined from Table 3 using the circuit ampacity
found on the unit rating plate. Use the smallest wire size
allowable in Table 4 from the unit disconnect to unit.
NOTE: A bracket is provided with the unit for mounting the
branch circuit disconnect to the unit. This is the recommended location for the disconnect. See Figure 16.
4 For through the base wiring entry reference Figure 17.
All fittings and conduit are field supplied for this application. Reference the chart with Figure 17 for proper hole
and conduit size.
IM 860
Table 3
ONE 1 21 1 30134139 3 45
40,000
TEN 133015 015 361630 37 30
ONE 0541 01 3 16230
60,000
TEN 9 0 10 0 10 24 11 0 25 0
ONE 041045047050153
80,000
TEN 6 45 7 30748815 18 45
ONE 0 33 0 36038 040 130
100,000
TEN 5246 061563615 0
METER TIME IN MINUTES AND SECONDS FOR NORMAL
INPUT RATING OF FURNACES EQUIPPED FOR NATURAL
OR LP GAS
INPUT
BTU/HR
METER
SIZE
CU. FT.
HEATING VALUE OF GAS BTU PER CU. FT.
900 1000 1040 1100 2500
MIN. SEC. MIN. SEC. MIN. SEC. MIN. SEC. MIN. SEC.
Figure 15: Condensate Drain
DO NOT OVERTIGHTEN DRAIN FITTING
Power supply to unit must be disconnected before making
field connections. To avoid electrical shock, personal injury
or death, be sure to rigorously adhere to field wiring procedures regarding proper lockout and tagout of components.
Figure 16: Recommended Branch Circuit Disconnect
Location
TO POWER
TO THERMOSTAT
BRANCH
CIRCUIT
DISCONNECT
I317A
▲▲
DANGER
!
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