Carrier GAS FURNACE 58MXA Operating instructions

58MCA, 58MXA
Multipoise Gas-Fired Condensing Furnace
Installation, Start-Up, and Operating Instructions
For Sizes 040—120 Series 111
CANADIAN GAS ASSOCIATION
ama
®
A PP R O VED
R
AIRFLOW
UPFLOW
A93040
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since the last issue.
Index
Page
DIMENSIONAL DRAWING........................................................2
SAFETY CONSIDERATIONS .....................................................3
Clearances to Combustibles......................................................3
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
PROCEDURE........................................................................3-4
INTRODUCTION ..........................................................................4
APPLICATIONS ......................................................................4-11
General ......................................................................................4
Upflow Applications..............................................................4-6
Downflow Applications.........................................................7-8
Horizontal Left (Supply-Air Discharge) Applications .........8-9
Horizontal Right (Supply-Air Discharge) Applications.....9-11
LOCATION ............................................................................11-12
General...............................................................................11-12
Furnace Location Relative to Cooling Equipment ................12
Hazardous Locations...............................................................12
INSTALLATION....................................................................12-16
Leveling Legs (If Desired)................................................12-13
Installation On a Concrete Slab .............................................13
Installation On a Combustible Floor (Downflow
Applications) ................................................................13-14
Installation In Horizontal Applications ..................................14
Filter Arrangement..................................................................15
Bottom Closure Panel.............................................................15
Gas Piping..........................................................................15-16
ELECTRICAL CONNECTIONS...........................................16-18
115-v Wiring......................................................................16-18
24-v Wiring.............................................................................18
Accessories..............................................................................18
DIRECT VENTING ...............................................................18-27
Removal of Existing Furnaces from
Common Vent Systems.....................................................18
Combustion-Air and Vent Piping .....................................18-25
Concentric Vent and Combustion-Air Termination
Kit Installation..............................................................25-27
HORIZONTAL
RIGHT
HORIZONTAL
LEFT
DOWNFLOW
AIRFLOW
AIRFLOW
AIRFLOW
Fig. 1—Multipoise Orientations
A93041
Multiventing and Vent Termination.......................................27
CONDENSATE DRAIN ........................................................27-29
General...............................................................................27-29
Application ..............................................................................29
Condensate Drain Protection ..................................................29
SEQUENCE OF OPERATION..............................................30-31
Heating Mode..........................................................................30
Cooling Mode .........................................................................30
Continuous Blower Mode.......................................................30
Heat Pump Mode ....................................................................30
Component Test.................................................................30-31
START-UP PROCEDURES ..................................................31-35
General ....................................................................................31
Prime Condensate Trap With Water ......................................31
Purge Gas Lines......................................................................31
Adjustments .......................................................................31-35
Set Gas Input Rate ............................................................31-34
Set Temperature Rise ........................................................34-35
Adjust Blower Off Delay (Heat Mode) .................................35
Set Thermostat Heat Anticipator............................................35
CHECK SAFETY CONTROLS..................................................35
Check Primary Limit Control.................................................35
Check Pressure Switch ...........................................................35
CHECKLIST...........................................................................35-36
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Catalog No. 565-830
Printed in U.S.A.
Form 58MXA-3SI
Pg 1
12-94
Replaces: 58MXA-2SI
Tab 6a 8a
2
11⁄4"
1"
14 1⁄2"
TYP
2-IN. VENT CONN
⁄2-IN. DIA
GAS CONN
1
26 15⁄16" TYP
23 1⁄4" TYP
SIDE INLET
SIDE INLET
⁄2-IN. DIA THERMOSTAT
ENTRY
22 11⁄16"
1
5⁄16"
24 1⁄2"
2-IN. COMBUSTIONAIR CONN
22
26 15⁄16"
26 1⁄4"
UNIT SIZE
040-08
040-12
060-12
060-16
080-12
080-16
080-20
100-16
100-20
120-20
CONDENSATE
DRAIN LOCATION
(UPFLOW)
9 7⁄16"
TYP
E
INLET
OUTLET
D
11⁄16"
D
15-7/8
15-7/8
15-7/8
15-7/8
15-7/8
15-7/8
19-3/8
19-3/8
19-3/8
22-7/8
Fig. 2—Dimensional Drawing
A
17-1/2
17-1/2
17-1/2
17-1/2
17-1/2
17-1/2
21
21
21
24-1/2
Dimensions (In.)
18 1⁄4"
TYP
9⁄16"
DIMPLE LOCATORS
FOR HORIZONTAL
HANGING
CONDENSATE
DRAIN LOCATION
(UPFLOW)
30
1⁄2"
CONDENSATE DRAIN
TRAP LOCATION
(DOWNFLOW &
HORIZONTAL RIGHT)
OR ALTERNATE
1
⁄2-IN. DIA GAS CONN
13⁄16"
NOTES: Minimum return-air opening at furnace:
1. For 800 CFM--16-In. round or 14 1/2 x 12-In. rectangle.
2. For 1200 CFM--20-In. round or 14 1/2 x 19 1/2-In. rectangle.
3. For 1600 CFM--22-In. round or 14 1/2 x 23 1/4-In. rectangle.
4. For airflow requirements above 1800 CFM, use both side inlets, a
combination of 1 side inlet and the bottom, or the bottom only.
11⁄16"
33 1⁄4"
TYP
5
32 ⁄8"
TYP
30 13⁄16"
29 11⁄16"
TYP
27 5⁄8"
27 9⁄16"
TYP
24 1⁄2"
17 5⁄16"
CONDENSATE
DRAIN TRAP
LOCATION
(ALTERNATE
UPFLOW)
⁄8-IN. DIA
ACCESSORY
POWER ENTRY
7
⁄8-IN. DIA
POWER CONN
7
CONDENSATE DRAIN
TRAP LOCATION
(DOWNFLOW &
HORIZONTAL LEFT)
13⁄16"
A
AIRFLOW
E
16
16
16
16
16
16
19-1/2
19-1/2
19-1/2
23
A93024
24 3⁄16"
BOTTOM INLET
22 1⁄4" TYP
SIDE INLET
22 11⁄16"
2-IN. VENT CONN
⁄2-IN. DIA
THERMOSTAT ENTRY
1
⁄8-IN. DIA
POWER CONN
7
⁄2-IN. DIA
GAS CONN
1
2-IN. COMBUSTIONAIR CONN
OUTLET
19"
22 5⁄16"
26 1⁄4"
26 15⁄16"
28 1⁄2"
11⁄16"
7⁄16"
1"
39 7⁄8"
5⁄16"
5⁄8"
13⁄16"
·
This unit complies with ANSI Z21.47 CAN/CGA-2.3-1993 standards.
This appliance is equipped only for altitudes 0 - 2,000 ft (0-610 m) for use with natural
gas and propane. A conversion kit, supplied by the manufacturer, shall be used to
convert to the alternate fuel or elevation.
This direct-vent, forced-air furnace is for indoor installation in a building constructed
on site or in a manufactured (mobile) home when using factory authorized kit. See
rating plate. For installation in alcove or closet at minimum clearances from combustible
material as shown below, minimum front clearance for service is 30 inches. (762 mm).
This furnace is for use with schedule-40 PVC, PVC-DWV, or ABS-DWV pipe, and must
not be vented in common with other gas-fired appliances. Construction through which
vent/air intake pipes may be installed is maximum 24 inches (600 mm), minimum 3/4 inches
(19 mm) thickness (including roofing materials).
Special venting system required. In Canada use certified venting system specified by
furnace manufacturer. See Installation Instructions provided with furnace. Flue gas
temperature 131°F (55°C) vent pressure positive.
MINIMUM CLEARANCE TO COMBUSTIBLE MATERIAL
INCHES
TOP
BOTTOM
1
1
1
0
++
0+
SIDES
0
0
1*
BACK
0
0
0
FRONT
VENT
3
3
3
0
0
0
UPFLOW
DOWNFLOW
HORIZONTAL
++ For Installation on combustible floors only when installed on special base No.
KGASB0201ALL.
* Clearance shown is for air inlet and air outlet end.
Horizontal position: Line contact is permissible only between lines formed by
intersections of top and two sides of furnace jacket, and building joists, studs, or framing.
+ 120,000 BTU Input Furnaces require 1 inch bottom clearance to combutible materials.
A93060
→ Fig. 3—Clearances to Combustibles
→ ELECTROSTATIC
SAFETY CONSIDERATIONS
Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained and qualified personnel should install, repair, or service heating equipment. Untrained
personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be performed by trained service personnel. When working on heating
equipment, observe precautions in literature, on tags, and on labels
attached to or shipped with unit and other safety precautions that
may apply.
DISCHARGE (ESD) PRECAUTIONS
PROCEDURE
Electrostatic discharge can affect electronic components.
Take precautions during furnace installation and servicing to
protect the furnace electronic control. Precautions will prevent electrostatic discharges from personnel and hand tools
which are held during the procedure. These precautions will
help to avoid exposing the control to electrostatic discharge
by putting the furnace, the control, and the person at the same
electrostatic potential.
Follow all safety codes. In the United States, follow all safety
codes including the National Fuel Gas Code (NFGC) NFPA No.
54-1992/ANSI Z223.1-1992. In Canada, refer to the current
edition of the National Standard of Canada CAN/CGA-B149.1and .2-M91 Natural Gas and Propane Installation Codes (NSCNGPIC). Wear safety glasses and work gloves. Have fire extinguisher available during start-up and adjustment procedures and
service calls.
1. Disconnect all power to the furnace. DO NOT TOUCH THE
CONTROL OR ANY WIRE CONNECTED TO THE CONTROL PRIOR TO DISCHARGING YOUR BODY’S ELECTROSTATIC CHARGE TO GROUND.
2. Firmly touch a clean, unpainted, metal surface of the furnace
chassis which is close to the control. Tools held in a person’s
hand during grounding will be satisfactorily discharged.
Recognize safety information. This is the safety-alert symbol .
When you see this symbol on unit or in instructions and manuals,
be alert to potential for personal injury.
3. After touching the chassis you may proceed to service the
control or connecting wires as long as you do nothing that
recharges your body with static electricity (for example; DO
NOT move or shuffle your feet, DO NOT touch ungrounded
objects, etc.).
Understand the signal words DANGER, WARNING, and CAUTION. These words are used with safety-alert symbol. DANGER
identifies most serious hazards which will result in severe personal
injury or death. WARNING signifies hazards which could result in
personal injury or death. CAUTION is used to identify unsafe
practices which would result in minor personal injury or product
and property damage. NOTE is used to highlight suggestions
which will result in enhanced installation, reliability, or operation.
4. If you touch ungrounded objects (recharge your body with
static electricity), firmly touch furnace again before touching
control or wires.
5. Use this procedure for installed and uninstalled (ungrounded)
furnaces.
3
These instructions cover minimum requirements for a safe installation and conform to existing national standards and safety codes.
In some instances, these instructions exceed certain local codes
and ordinances, especially those that may not have kept pace with
changing residential construction practices. We require these
instructions as a minimum for a safe installation.
6. Before removing a new control from its container, discharge
your body’s electrostatic charge to ground to protect the
control from damage. If the control is to be installed in a
furnace, follow items 1 through 5 before bringing the control
or yourself into contact with the furnace. Put all used AND
new controls into containers before touching ungrounded
objects.
7. An ESD service kit (available from commercial sources) may
also be used to prevent ESD damage.
Application of this furnace should be indoors with special
attention given to vent sizing and material, gas input rate, air
temperature rise, unit leveling, and unit sizing. Improper
installation or misapplication of furnace can require excessive
servicing or cause premature component failure.
INTRODUCTION
58MCA and 58MXA Multipoise Condensing Gas-Fired
Furnaces are A.G.A./C.G.A. certified for natural and propane
gases and for installation in alcoves, attics, basements, closets,
utility rooms, crawlspaces, and garages. The 58MCA and 58MXA
Furnaces are A.G.A./C.G.A. approved for use in manufactured
(mobile) homes when factory accessory conversion kit is used.
These furnaces are suitable for installation in a residence built on
site or a manufactured residence completed at final site. The design
of this furnace line is NOT A.G.A./C.G.A. certified for installation
in recreation vehicles or outdoors.
→ The
Improper installation, adjustment, alteration, service, maintenance, or use can cause carbon monoxide poisoning, explosion, fire, electrical shock, or other conditions which may
cause personal injury or property damage. Consult a qualified
installer, service agency, local gas supplier, or your distributor or branch for information or assistance. The qualified
installer or agency must use only factory-authorized and
listed kits or accessories when modifying this product. Failure
to follow this warning could result in electrical shock, fire,
personal injury, or death.
These furnaces SHALL NOT be installed directly on carpeting,
tile, or any other combustible material other than wood flooring. In
downflow installations, factory accessory floor base MUST be
used when installed on combustible materials and wood flooring.
These furnaces are shipped with the drain and pressure tubes
connected for UPFLOW applications. Minor modifications are
required when used in DOWNFLOW, HORIZONTAL RIGHT, or
HORIZONTAL LEFT (supply-air discharge direction) applications as shown in Fig. 1. See details in Applications section.
For accessory installation details, refer to applicable installation
literature.
APPLICATIONS
Step 1—General
These furnaces are shipped with the following materials to assist in
proper furnace installation. These materials are shipped in the main
blower compartment.
Some assembly and modifications are required for furnaces
installed in any of the 4 applications shown in Fig. 1. All drain and
pressure tubes are connected as shown in Fig. 5. See appropriate
application instructions for these procedures.
Installer Packet includes:
Installation, Start-Up, and Operating Instructions
Service and Maintenance Instructions
User’s Information Manual
Warranty Certificate
Loose Parts Bag includes:
Quantity
Pressure tube extension
1
Collector box or condensate trap extension tube
1
Inducer housing drain tube
1
1/2-in. CPVC street elbow
2
Drain tube coupling
1
Drain tube coupling grommet
1
Vent and combustion-air pipe support
2
Combustion-air pipe perforated disk assembly
1
Vent Pipe Extension (ONLY supplied with some furnaces)
Step 2—Upflow Applications
An upflow furnace application is where furnace blower is located
below combustion and controls section of furnace and conditioned
air is discharged upwards.
CONDENSATE TRAP LOCATION (FACTORY-SHIPPED
ORIENTATION)
The condensate trap is factory installed in the blower shelf and
factory connected for UPFLOW applications. A factory-supplied
tube is used to extend the condensate trap drain connection to the
desired furnace side for field drain attachment. See Condensate
Trap Tubing (Factory-Shipped Orientation) section for drain tube
extension details.
Before installing the furnace in the United States, refer to the
current edition of the NFGC. For further information, the NFGC is
available from National Fire Protection Association Inc., Batterymarch Park, Quincy, MA 02269; American Gas Association, 1515
Wilson Boulevard, Arlington, VA 22209; or from Literature
Distribution.
CONDENSATE TRAP TUBING (FACTORY-SHIPPED
ORIENTATION)
NOTE: See Fig. 5 or tube routing label on main furnace door to
confirm location of these tubes.
Before installing the furnace in Canada, refer to the current edition
of the NSCNGPIC. Contact Standards Department of Canadian
Gas Association, 55 Scarsdale Road, Don Mills, Ontario, Canada
M3B 2R3.
Installations must comply with regulations of serving gas supplier
and local building, heating, plumbing, or other codes in effect in
area in which installation is made. In absence of local codes,
installation must conform with NFGC.
These tubes should be factory attached to condensate trap and
pressure switch ready for use in UPFLOW applications. These
tubes can be identified by their connection location and also
by a color label on each tube. These tubes are identified as
follows: collector box drain tube (blue label), inducer housing
drain tube (violet label or molded), relief port tube (green
label), and pressure switch tube (pink label).
2. Condensate Trap Drain Tube
Canadian installations must be made in accordance with NSCNGPIC and all authorities having jurisdiction.
The condensate trap drain connection must be extended for
field attachment by doing the following:
1. Collector Box Drain, Inducer Housing Drain, Relief Port, and
Pressure Switch Tubes
4
FURNACE
DOOR
BLOWER SHELF
CONDENSATE
TRAP
CONDENSATE
TRAP (INSIDE)
FURNACE
DOOR
FURNACE
SIDE
4 78
FURNACE
SIDE
4
534
534
4
FIELD
DRAIN
CONN
ALTERNATE DRAIN
TUBE LOCATION
26 1 4
26 1 4
11 2
SIDE VIEW
CONDENSATE TRAP
DRAIN TUBE LOCATION
FRONT VIEW
END VIEW
SLOT FOR SCREW
HORIZONTAL
APPLICATION
(OPTIONAL)
FRONT VIEW
HORIZONTAL
APPLICATIONS
DOWNFLOW AND ALTERNATE
EXTERNAL UPFLOW APPLICATIONS
UPFLOW APPLICATIONS
34
FIELD
DRAIN
CONN
1⁄4 OD
COLLECTOR BOX TO
TRAP RELIEF PORT
11 2
1⁄2 OD
INDUCER HOUSING
DRAIN CONNECTION
34
5⁄8 OD
COLLECTOR BOX
DRAIN CONNECTION
71 8
SCREW HOLE FOR
UPFLOW OR DOWNFLOW APPLICATIONS
(OPTIONAL)
13 4
78
WIRE TIE
GUIDES
(WHEN USED)
21 4
FRONT VIEW
1⁄2-IN.
PVC OR CPVC
SIDE VIEW
A93026
Fig. 4—Condensate Trap
a. Determine location of field drain connection. (See Fig. 2 or
5.)
CONDENSATE TRAP LOCATION (ALTERNATE UPFLOW
ORIENTATION)
NOTE: If internal filter is used, drain tube should be located to
opposite side of casing of return duct attachment to assist in filter
removal.
An alternate location for the condensate trap is the left-hand side
of casing. (See Fig. 2 and 6.)
NOTE: If the alternate left-hand side of casing location is used,
the factory-connected drain and relief port tubes must be disconnected and modified for attachment. See Condensate Trap Tubing
(Alternate Upflow Orientation) section for tubing attachment.
b. Remove and discard casing drain hole plug button from
desired side.
c. Install drain tube coupling grommet (factory supplied in
loose parts bag) in selected casing hole.
To relocate condensate trap to the left-hand side, perform the
following:
d. Slide drain tube coupling (factory supplied in loose parts
bag) through grommet ensuring long end of coupling faces
blower.
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs inward
and rotating trap.
e. Cement 2 factory-supplied 1/2-in. street CPVC elbows to
the rigid drain tube connection on the condensate trap. (See
Fig. 5.) These elbows must be cemented together and
cemented to condensate trap drain connection.
3. Remove casing hole filler cap from casing hole. (See Fig. 2 or
6.)
4. Install casing hole filler cap into blower shelf hole where trap
was removed.
NOTE: Failure to use CPVC elbows may allow drain to kink and
prevent draining.
5. Install condensate trap into left-hand side casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
CONDENSATE TRAP TUBING (ALTERNATE UPFLOW
ORIENTATION)
NOTE: See Fig. 6 or tube routing label on main furnace door to
confirm location of these tubes.
f. Connect larger diameter drain tube and clamp (factory
supplied in loose parts bag) to condensate trap and clamp
securely.
g. Route tube to coupling and cut to appropriate length.
h. Attach tube to coupling and clamp securely.
5
PLUG
CAP
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
TUBE (PINK)
PLUG
CAP
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
TUBE (PINK)
INDUCER HOUSING
(MOLDED) DRAIN
TUBE (BEHIND
COLLECTOR BOX
DRAIN TUBE)
COLLECTOR BOX
DRAIN TUBE (BLUE)
COLLECTOR BOX
TUBE (GREEN)
CONDENSATE
TRAP
COLLECTOR BOX
DRAIN TUBE (BLUE)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (LEFT
DRAIN OPTION)
CONDENSATE
TRAP
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
FIELD-INSTALLED
FACTORY-SUPPLIED
1⁄2-IN. CPVC STREET
ELBOWS (2) FOR
LEFT DRAIN OPTION
INDUCER
HOUSING
DRAIN TUBE
(VIOLET)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (RIGHT
DRAIN OPTION)
A94163
A94164
Fig. 5—Factory-Shipped Upflow Tube Configuration
(Shown With Blower Access Panel Removed)
Fig. 6—Alternate Upflow Tube Configuration and
Trap Location
1. Collector Box Drain Tube
PRESSURE SWITCH TUBING
The LOWER collector box pressure tube (pink label) is factory
connected to the pressure switch and should not require any
modification.
NOTE: See Fig. 5 or 6 or tube routing label on main furnace door
to check for proper connections.
UPPER COLLECTOR BOX AND INDUCER HOUSING
(UNUSED) DRAIN CONNECTIONS
Upper Collector Box Drain Connection
Attached to the UPPER collector box drain connection is a
factory-installed corrugated, plugged tube (blue and white striped
label). This tube is plugged to prevent condensate leakage in this
application. Ensure this tube is plugged.
NOTE: See Fig. 5 or 6 or tube routing label on main furnace door
to check for proper connections.
Upper Inducer Housing Drain Connection
Attached to the UPPER (unused) inducer housing drain connection
is a cap and clamp. This cap is used to prevent condensate leakage
in this application. Ensure this connection is capped.
NOTE: See Fig. 5 or 6 or tube routing label on main furnace door
to check for proper connections.
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain Protection section for recommendations and procedures.
Connect collector box drain tube (blue label) to condensate
trap.
NOTE: On 17-1/2-in. wide furnaces ONLY, cut tube between
corrugated sections to prevent kinks from occurring.
2. Inducer Housing Drain Tube
a. Remove and discard LOWER (molded) inducer housing
drain tube which was previously connected to condensate
trap.
b. Use inducer housing drain extension tube (violet label and
factory supplied in loose parts bag) to connect LOWER
inducer housing drain connection to the condensate trap.
c. Determine appropriate length, cut, and connect tube.
d. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
a. Connect relief port tube (green label) to condensate trap.
b. Use smaller diameter tube (factory supplied in loose parts
bag) to extend this tube if required.
c. Determine appropriate length, cut, and connect tube.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
Refer to Condensate Drain section for recommendations and
procedures.
6
COLLECTOR BOX
DRAIN TUBE (BLUE)
CAP
PLUG
PLUG
CAP
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
DRAIN TUBE (BLUE)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
EXTENSION TUBE
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
CONDENSATE
TRAP
CONDENSATE
TRAP
COLLECTOR BOX
EXTENSION
DRAIN TUBE
INDUCER HOUSING
DRAIN TUBE (VIOLET)
DRAIN TUBE
COUPLING
A94165
A94166
Fig. 7—Downflow Tube Configuration
(Left-Hand Trap Installation)
Fig. 8—Downflow Tube Configuration
(Right-Hand Trap Installation)
Step 3—Downflow Applications
c. Connect LOWER collector box drain connection to condensate trap.
A downflow furnace application is where furnace blower is located
above combustion and controls section of furnace and conditioned
air is discharged downwards.
(1.) Condensate Trap Located on Left Side of Casing
(a.) Connect LOWER collector box drain tube (blue
and white striped label) to condensate trap. Tube
does not need to be cut.
CONDENSATE TRAP LOCATION
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2, 7, or 8.
(b.) Clamp tube to prevent any condensate leakage.
(2.) Condensate Trap Located on Right Side of Casing
To relocate condensate trap from the blower shelf to desired
location, perform the following:
(a.) Install drain tube coupling (factory supplied in
loose parts bag) into collector box drain tube
(blue and white striped label) which was previously plugged.
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs inward
and rotating trap.
(b.) Connect larger diameter drain tube (factory supplied in loose parts bag) to drain tube coupling,
extending collector box drain tube for connection
to condensate trap.
3. Remove casing hole filler cap from casing hole. (See Fig. 2, 7,
or 8.)
4. Install casing hole filler cap into blower shelf hole where trap
was removed.
(c.) Route extended collector box drain tube between
gas valve and inlet housing as shown in Fig. 8.
5. Install condensate trap into desired casing hole by inserting
tube connection stubs through casing hole and rotating until
tabs snap into locking position.
(d.) Determine appropriate length and cut.
(e.) Connect to condensate trap.
(f.) Clamp tube to prevent any condensate leakage.
CONDENSATE TRAP TUBING
2. Inducer Housing Drain Tube
NOTE: See Fig. 7 or 8 or tube routing label on main furnace door
to check for proper connections.
a. Remove factory-installed cap and clamp from LOWER
inducer housing drain connection.
1. Collector Box Drain Tube
b. Remove and discard UPPER (molded) inducer housing
drain tube which was previously connected to condensate
trap.
a. Remove factory-installed plug from LOWER collector box
drain tube (blue and white striped label).
b. Install removed clamp and plug into UPPER collector box
drain tube (blue label) which was connected to condensate
trap.
c. Install cap and clamp on UPPER inducer housing drain
connection where molded drain tube was removed.
7
d. Use inducer housing drain tube (violet label and factory
supplied in loose parts bag) to connect LOWER inducer
housing drain connection to the condensate trap.
other collector box pressure tube (green label) which was factory
connected to the condensate trap relief port connection MUST be
connected to the pressure switch in DOWNFLOW or HORIZONTAL RIGHT applications.
e. Connect inducer housing drain connection to condensate
trap.
NOTE: See Fig. 7 or 8 or tube routing label on main furnace door
to check for proper connections.
(1.) Condensate Trap Located on Left Side of Casing
Relocate tubes as described below.
(a.) Determine appropriate length and cut.
1. Disconnect collector box pressure tube (pink label) attached to
pressure switch.
(b.) Connect tube to condensate trap.
(c.) Clamp tube to prevent any condensate leakage.
2. Use smaller diameter tube (factory supplied in loose parts bag)
to extend collector box pressure tube (green label) which was
previously connected to condensate trap relief port connection.
(2.) Condensate Trap Located on Right Side of Casing
(a.) Route inducer housing drain tube (violet label)
between gas valve and inlet housing behind collector box drain tube.
3. Connect collector box pressure tube (green label) to pressure
switch connection labeled "collector box."
(b.) Determine appropriate length and cut.
(c.) Connect tube to condensate trap.
4. Use remaining smaller diameter tube (factory supplied in
loose parts bag) to extend collector box pressure tube (pink
label) which was previously connected to pressure switch.
(d.) Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
Refer to Pressure Switch Tubing section for connection
procedure.
5. Route this extended tube (pink label) to condensate trap relief
port connection.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
6. Determine appropriate length, cut, and connect tube.
Refer to Condensate Drain section for recommendations and
procedures.
7. Clamp tube to relief port connection.
CONDENSATE TRAP FREEZE PROTECTION
PRESSURE SWITCH TUBING
Refer to Condensate Drain Protection section for recommendations and procedures.
One collector box pressure tube (pink label) is factory connected to
the pressure switch for use when furnace is installed in UPFLOW
or HORIZONTAL LEFT applications. This tube MUST be disconnected and used for the condensate trap relief port tube. The
Step 4—Horizontal Left (Supply-Air Discharge)
Applications
PLUG
CAP
COLLECTOR BOX
DRAIN TUBE
(BLUE AND WHITE STRIPED)
AUXILIARY "J" BOX
RELOCATED HERE
CONDENSATE
TRAP
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR
BOX EXTENSION
DRAIN TUBE
COLLECTOR BOX
EXTENSION TUBE
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR BOX
DRAIN TUBE (BLUE)
DRAIN TUBE COUPLING
COLLECTOR BOX TUBE (PINK)
RELOCATE TUBE BETWEEN BLOWER SHELF AND INDUCER HOUSING FOR
040, 060, AND 080 HEATING INPUT FURNACES
A93302
Fig. 9—Horizontal Left Tube Configuration
8
A horizontal left furnace application is where furnace blower is
located to the right of combustion and controls section of furnace
and conditioned air is discharged to the left.
d. Clamp tube to prevent any condensate leakage.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
Refer to Condensate Drain section for recommendations and
procedures.
Local codes may require a drain pan under entire furnace and
condensate trap when a condensing furnace is used in an attic
application or over a finished ceiling.
PRESSURE SWITCH TUBING
The LOWER collector box pressure tube (pink label) is factory
connected to the pressure switch and should not require any
modification.
NOTE: In Canada, installations shall be in accordance with
current NSCNGPIC and/or local codes.
NOTE: See Fig. 9 or tube routing label on main furnace door to
check for proper connections.
NOTE: The auxiliary junction box (J-Box) MUST be relocated to
opposite side of furnace casing. (See Fig. 9.) See Electrical
Connection section for J-Box relocation.
CONDENSATE TRAP FREEZE PROTECTION
CONDENSATE TRAP LOCATION
Refer to Condensate Drain Protection section for recommendations and procedures.
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2 or 9.
CONSTRUCT A WORKING PLATFORM
Construct working platform where all required furnace clearances
are met. (See Fig. 3 and 10.)
To relocate condensate trap from the blower shelf to desired
location, perform the following:
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs inward
and rotating trap.
The condensate trap MUST be installed below furnace. See
Fig. 4 for dimensions. The drain connection to condensate
trap must also be properly sloped to an open drain.
3. Remove casing hole filler cap from casing hole. (See Fig. 2 or
9.)
NOTE: Combustion-air and vent pipes are restricted to a minimum length of 5 ft. (See Table 5.)
4. Install casing hole filler cap into blower shelf hole where trap
was removed.
NOTE: A 12-in. minimum horizontal pipe section is recommended with short (5 to 8 ft) vent systems. This recommendation
is to reduce excessive condensate droplets from exiting the vent
pipe. (See Fig. 10 or 29.)
5. Install condensate trap into casing hole by inserting tube
connection stubs through casing hole and rotating until tabs
snap into locking position.
CONDENSATE TRAP TUBING
Step 5—Horizontal Right (Supply-Air Discharge)
Applications
NOTE: See Fig. 9 or tube routing label on main furnace door to
check for proper connections.
A horizontal right furnace application is where furnace blower is
located to the left of combustion and controls section of furnace
and conditioned air is discharged to the right.
1. Collector Box Drain Tube
a. Install drain tube coupling (factory supplied in loose parts
bag) into collector box drain tube (blue label) which was
previously connected to condensate trap.
b. Connect large diameter drain tube and clamp (factory
supplied in loose parts bag) to drain tube coupling, extending collector box drain tube.
Local codes may require a drain pan under entire furnace and
condensate trap when a condensing furnace is used in attic
application or over a finished ceiling.
c. Route extended tube (blue label) to condensate trap and cut
to appropriate length.
NOTE: In Canada, installations shall be in accordance with
current NSCNGPIC Installation Codes and/or local codes.
d. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube
CONDENSATE TRAP LOCATION
a. Remove and discard LOWER (molded) inducer housing
drain tube which was previously connected to condensate
trap.
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2 or 11.
b. Use inducer housing drain extension tube (violet label and
factory supplied in loose parts bag) to connect LOWER
inducer housing drain connection to the condensate trap.
To relocate condensate trap from the blower shelf to desired
location, perform the following:
1. Remove 3 tubes connected to condensate trap.
c. Determine appropriate length, cut, and connect tube.
2. Remove trap from blower shelf by gently pushing tabs inward
and rotating trap.
d. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
3. Remove casing hole filler cap from casing hole. (See Fig. 2 or
11.)
a. Use smaller diameter tube (factory supplied in loose parts
bag) to extend collector box tube (green label) which was
previously connected to the condensate trap.
4. Install casing hole filler cap into blower shelf hole where trap
was removed.
b. Route extended collector box pressure tube to relief port
connection on the condensate trap.
5. Install condensate trap into casing hole by inserting tube
connection stubs through casing hole and rotating until tabs
snap into locking position.
c. Determine appropriate length, cut, and connect tube.
9
COMBUSTION – AIR
INTAKE
VENT
30″ MIN
WORK AREA
5 3⁄4″
MANUAL
SHUTOFF
GAS VALVE
A 12-IN. MIN HORIZONTAL PIPE
SECTION IS RECOMMENDED WITH
SHORT (5 TO 8 FT) VENT SYSTEMS
TO REDUCE EXCESSIVE
CONDENSATE DROPLETS FROM
EXITING THE VENT PIPE.
ACCESS OPENING
FOR TRAP
SEDIMENT
TRAP
DRAIN
CONDENSATE
TRAP
NOTE: LOCAL CODES MAY REQUIRE A DRAIN PAN UNDER THE
FURNACE AND CONDENSATE TRAP WHEN A CONDENSING
FURNACE IS INSTALLED ABOVE FINISHED CEILINGS.
A93031
Fig. 10—Attic Location and Working Platform
CONDENSATE TRAP TUBING
Refer to Pressure Switch Tubing section for connection
procedure.
NOTE: See Fig. 11 or tube routing label on main furnace door to
check for proper connections.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
1. Collector Box Drain Tube
Refer to Condensate Drain section for recommendations and
procedures.
a. Remove factory-installed plug from LOWER collector box
drain tube (blue and white striped label).
PRESSURE SWITCH TUBING
b. Install removed clamp and plug into UPPER collector box
drain tube (blue label) which was previously connected to
condensate trap.
One collector box pressure tube (pink label) is factory connected to
the pressure switch for use when furnace is installed in UPFLOW
or HORIZONTAL LEFT applications. This tube MUST be disconnected and used for the condensate trap relief port tube. The
other collector box pressure tube (green label) which was factory
connected to the condensate trap relief port connection MUST be
connected to the pressure switch in DOWNFLOW or HORIZONTAL RIGHT applications.
c. Connect LOWER collector box drain tube (blue and white
striped label) to condensate trap. Tube does not need to be
cut.
d. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube
a. Remove factory-installed cap and clamp from LOWER
inducer housing drain connection.
NOTE: See Fig. 11 or tube routing label on main furnace door to
check for proper connections.
b. Remove and discard UPPER (molded) inducer housing
drain tube which was previously connected to condensate
trap.
Relocate tubes as described below.
1. Disconnect collector box pressure tube (pink label) attached to
pressure switch.
c. Install cap and clamp on UPPER inducer housing drain
connection where molded drain tube was removed.
2. Use smaller diameter tube (factory supplied in loose parts bag)
to extend collector box pressure tube (green label) which was
previously connected to condensate trap relief port connection.
d. Use inducer housing drain extension tube (violet label and
factory supplied in loose parts bag) to connect LOWER
inducer housing drain connection to condensate trap.
3. Connect collector box pressure tube (green label) to pressure
switch connection labeled COLLECTOR BOX.
e. Determine appropriate length, cut, and connect tube to
condensate trap.
4. Use remaining smaller diameter tube (factory supplied in
loose parts bag) to extend collector box pressure tube (pink
label) which was previously connected to pressure switch.
f. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
10
CAP
COLLECTOR BOX DRAIN TUBE (BLUE)
COLLECTOR BOX TUBE (GREEN)
COLLECTOR BOX EXTENSION TUBE
COLLECTOR BOX TUBE (PINK)
PLUG
CONDENSATE
TRAP
COLLECTOR BOX DRAIN TUBE
(BLUE AND WHITE STRIPED)
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR BOX
EXTENSION TUBE
A93303
Fig. 11—Horizontal Right Tube Configuration
5. Route this extended tube (pink label) to condensate trap relief
port connection.
6. Determine appropriate length, cut, and connect tube.
7. Clamp tube to relief port connection.
LEVEL (0″)
TO
1⁄2″ MAX
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain Protection section for recommendations and procedures.
CONSTRUCT A WORKING PLATFORM
FRONT
LEVEL (0″)
TO
1⁄2″ MAX
UPFLOW OR DOWNFLOW
Construct working platform where all required furnace clearances
are met. (See Fig. 3 and 10.)
FRONT
HORIZONTAL
A93025
NOTE: For proper furnace operation, install furnace so that it is
level or pitched forward within 1/2 in. to ensure proper condensate
drainage from secondary heat exchangers.
The condensate trap MUST be installed below furnace. See
Fig. 4 for dimensions. The drain connection to condensate
trap must also be properly sloped to an open drain.
Locate furnace as close to center of air distribution system as
possible.
Locate furnace so combustion-air pipe maximum lengths are not
exceeded. Refer to Table 5—Maximum Allowable Pipe Length.
NOTE: Combustion-air and vent pipes are restricted to a minimum length of 5 ft. (See Table 5.)
NOTE: A 12-in. minimum horizontal pipe section is recommended with short (5 to 8 ft) vent systems. This recommendation
is to reduce excessive condensate droplets from exiting the vent
pipe. (See Fig. 10 or 29.)
If these furnaces are used during construction when adhesives, sealers, and/or new carpets are being installed, make
sure all combustion and circulating air requirements are
followed. If operation of furnace is required during construction, use clean outside air for combustion and ventilation.
Compounds of chlorine and fluorine, when burned with
combustion air, form acids which will cause corrosion of heat
exchangers. Some of these compounds are found in paneling,
dry wall adhesives, paints, thinners, masonry cleaning materials, and many other solvents commonly used in construction
process.
Excessive exposure to contaminated combustion air will
result in safety and performance related problems.
LOCATION
Step 1—General
When a furnace is installed so that supply ducts carry air to areas
outside the space containing the furnace, return air must also be
handled by ducts sealed to furnace casing. The ducts terminate
outside the space containing the furnace to ensure there will not be
a negative pressure condition within equipment room or space.
Furnace may be located in a confined space without special
provisions for dilution or ventilation air. This furnace must be
installed so electrical components are protected from water.
11
FRONT
°F
°F
32°F MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED
RETURN
AIR
MAX 85°F
MIN 55°F
A93042
A93058
NOTE: These furnaces are designed for a minimum continuous
return-air temperature of 60°F or intermittent operation down to 55°F
such as when used with a night setback thermostat. Return-air
temperature must not exceed a maximum of 85°F. Failure to follow
these return-air temperature limits may affect reliability of heat
exchangers, motors, and controls.
If these furnaces are installed in an unconditioned space
where ambient temperatures may be 32°F or lower, freeze
protection measures must be taken.
Step 3—Hazardous Locations
FRONT
B
A
C
K
BACK
FRONT
A93043
A93044
Do not install furnace on its back. Safety control operation
will be adversely affected. Never connect return-air ducts to
back of furnace. Failure to follow this warning could result in
fire, personal injury, or death.
When furnace is installed in a residential garage, it must be
installed so that burners and ignition sources are located a
minimum of 18 in. above floor. The furnace must be located
or protected to avoid physical damage by vehicles. When
furnace is installed in a public garage, airplane hangar, or
other building having a hazardous atmosphere, unit must be
installed in accordance with requirements of National Fire
Protection Association, Inc.
Provide ample space for servicing and cleaning. Always comply
with minimum fire protection clearances shown on units clearance
to combustibles label. (See Fig. 3.) Locate furnace where available
electric power and gas supplies meet specifications on furnace
rating plate.
INSTALLATION
Step 2—Furnace Location Relative to Cooling
Equipment
Step 1—Leveling Legs (If Desired)
The cooling coil must be installed parallel with or on downstream
side of furnace to avoid condensation in heat exchanger. When
installed parallel with a furnace, dampers or other means used to
control flow of air must prevent chilled air from entering furnace.
If dampers are manually operated, they must be equipped with a
means to prevent operation of either unit unless damper is in
full-heat or full-cool position.
NOTE: The maximum length of bolt should not exceed 1-1/2 in.
When furnace is used in upflow position with side inlet(s), leveling
legs may be desired. (See Fig. 12.) Install field-supplied,
corrosion-resistant 5/16-in. machine bolts and nuts.
1. Position furnace on its back. Locate and drill a 5/16-in.
diameter hole in each bottom corner of furnace. (See Fig. 12.)
Holes in bottom closure panel may be used as guide locations.
12
5⁄16″
FURNACE
5⁄16″
1 3⁄4″
1 3⁄4″
PLENUM
A73383
Fig. 14—Furnace on a Concrete Slab
(Non-Garage Installation)
5⁄16″
Step 3—Installation on a Combustible Floor (Downflow
Applications)
1. Cut and frame hole in floor per dimensions in Installation
Instructions packaged with downflow subbase kit.
NOTE: Remove furnace perforated, discharge duct flanges when
they interfere with mating flanges on coil on downflow subbase.
To remove furnace perforated, discharge duct flange, use wide
duct pliers or duct flange tool to bend flange back-and-forth until
it breaks off. Be careful of sharp edges. (See Fig. 15.)
5⁄16″
1 3⁄4″
1 3⁄4″
A89014
Fig. 12—Leveling Legs
2. For each hole, install nut on bolt and then install bolt and nut
in hole. (Install flat washer if desired.)
3. Install another nut on other side of furnace base. (Install flat
washer if desired.)
LEVEL (0″)
TO
1⁄2″ MAX
4. Adjust outside nut to provide desired height, and tighten inside
nut to secure arrangement.
NOTE: Bottom closure must be used when leveling legs are used.
See Bottom Closure Panel section.
FRONT
LEVEL (0″)
TO
1⁄2″ MAX
UPFLOW OR DOWNFLOW
FRONT
HORIZONTAL
Step 2—Installation on a Concrete Slab
A93025
1. Construct hole in floor per dimensions in Fig. 13.
NOTE: For proper furnace operation, install furnace so that it is
level or pitched forward within 1/2 in. to ensure proper condensate
drainage from secondary heat exchangers.
2. Place plenum and furnace as shown in Fig. 14.
PERFORATED
DISCHARGE DUCT
FLANGE
NO
A
B
HOLE IN
FLOOR
YES
210°
MIN
YES
A73382
Opening Dimensions (In.)
FURNACE
CASING WIDTH
A
17-1/2
21
24-1/2
16-7/16
19-7/8
23-7/16
Fig. 15—Duct Flanges
B
Heat Only
19-5/8
19-5/8
19-5/8
Heat/Cool*
19-7/16
19-7/16
19-7/16
* These dimensions apply when a model CB or CD Evaporator Coil casing is
to be installed.
Fig. 13—Floor Opening in Concrete Slab
13
A93029
Do not bend duct flanges inward as shown in Fig. 15. This
will affect airflow across heat exchangers and may cause
limited cycling or premature heat exchanger failure. Remove
duct flange completely or bend it inward a minimum of 210°
as shown in Fig. 15.
FURNACE
(OR COIL CASING
WHEN USED)
2. When complete, downflow subbase, plenum, and furnace (or
coil casing when used) should be installed as shown in Fig. 16.
Step 4—Installation in Horizontal Applications
DOWNFLOW
SUBBASE
These furnaces can be installed horizontally in either horizontal
left or right discharge position. In a crawlspace, furnace can either
be hung from floor joist or installed on suitable blocks or pad.
Furnace can be suspended from each corner by hanger bolts. (See
Fig. 17.) Cut hanger bolts (4 each 3/8-in. all-thread rod) to desired
length. Use 1 X 3/8-in. flat washers, 3/8-in. lockwashers, and
3/8-in. nuts on hanger rods as shown in Fig. 17. Dimples are
provided for hole locations. (See Fig. 2.)
SHEET METAL
PLENUM
A78651
The entire length of furnace MUST be supported when
furnace is used in a horizontal position to ensure proper
draining.
Fig. 16—Furnace, Plenum, and Subbase Installed
on a Combustible Floor
3⁄8-IN.
ANGLE
IRON OR
EQUIVALENT
ROD
5 3⁄4″
ALTERNATE SUPPORT
LOCATION 4-IN. MIN
8-IN. MAX
(B)
(A)
DRAIN
(B)
(A)
(A) ROD LOCATION
USING DIMPLE
LOCATORS
(SEE DIMENSIONAL
DWG FOR
LOCATIONS)
(B)
3/8-IN.
HEX NUT
& WASHER (4)
REQD PER ROD
(A) PREFERRED ROD LOCATION
(B) ALTERNATE ROD LOCATION
(A)
(B)
13/16-IN. MAX
ALTERNATE SUPPORT
LOCATION FROM BACK
NOTES: 1. A 1 In. clearance minimum between top of
furnace and combustible material.
2. The entire length of furnace must be
supported when furnace is used in horizontal
position to ensure proper drainage.
A93304
Fig. 17—Crawlspace Horizontal Application
14
Step 5—Filter Arrangement
3″
Never operate unit without a filter or with blower access
panel removed.
24 1/2″
Factory-supplied washable framed filters are shipped in blower
compartment. Determine location for filter and relocate filter
retaining wire if necessary. See Table 1 to determine correct filter
size for desired filter location. Table 1 indicates filter size,
location, and quantity shipped with this furnace. See Fig. 2 for
location and size of bottom and side return-air openings.
1″
FIELD-SUPPLIED
FILTER FILLER
STRIP FOR
171⁄ 2-IN. WIDE
CASINGS ONLY.
INSTALL UNDER
FILTER.
Table 1—Filter Information
FURNACE
FILTER SIZE (IN.)*
FILTER TYPE
CASING
FRAMED
Side
Return
Bottom
Return
WIDTH (IN.)
17-1/2
(1) 16 X 25 X 1† (1) 16 X 25 X 1
Cleanable
21
(1) 16 X 25 X 1 (1) 20 X 25 X 1†
Cleanable
24-1/2
(2) 16 X 25 X 1† (1) 24 X 25 X 1
Cleanable
* Filters can be field modified by cutting frame as marked and folding to desired
size. Alternate sizes can be ordered from your distributor or dealer.
† Factory-provided with furnace.
WASHABLE
FILTER
Air delivery above 1800 CFM requires that both sides, a
combination of 1 side and bottom, or bottom only of furnace
be used for return air.
NOTE: Side return-air openings can ONLY be used in UPFLOW
configurations. Install filter(s) as shown in Fig. 18.
WASHABLE
FILTER
FILTER
SUPPORT
FILTER
RETAINER
A93321
FILTER
RETAINER
Fig. 19—Bottom Filter Arrangement
3. Remove bottom closure panel.
4. Reinstall front filler panel and screws.
A93045
Fig. 18—Filter Installed for Side Inlet
Bottom return-air opening may be used with all 4 orientations.
Filter may need to be cut to fit some furnace widths. Install filter
as shown in Fig. 19.
BOTTOM
CLOSURE
PANEL
NOTE: Remove and discard bottom closure panel when bottom
inlet is used.
FRONT FILLER
PANEL
Step 6—Bottom Closure Panel
These furnaces are shipped with bottom enclosure panel installed
in bottom return-air opening. This panel MUST be in place when
side return air is used.
A93047
Fig. 20—Removing Bottom Closure Panel
To remove bottom closure panel, perform following:
Step 7—Gas Piping
1. Tilt or raise furnace and remove 2 screws holding front filler
panel. (See Fig. 20.)
Gas piping must be installed in accordance with national and local
codes. Refer to current edition of NFGC. Canadian installations
must be made in accordance with NSCNGPIC and all authorities
2. Rotate front filler panel downward to release holding tabs.
15
having jurisdiction. Gas supply line should be a separate line
running directly from meter to furnace, if possible. Refer to Table
2 for recommended gas pipe sizing. Risers must be used to connect
to furnace and to meter. Support all gas piping with appropriate
straps, hangers, etc. Use a minimum of 1 hanger every 6 ft. Joint
compound (pipe dope) should be applied sparingly and only to
male threads of joints. Pipe dope must be resistant to propane gas.
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
SEDIMENT
TRAP
UNION
Connect gas pipe to furnace using a backup wrench to avoid
damaging gas controls.
Gas valve knob MUST be facing forward or tilted upward.
Failure to follow this warning could result in property damage
or death.
A93324
Fig. 21—Typical Gas Pipe Arrangement
NOTE: The gas valve inlet press tap connection is suitable to use
as test gage connection providing test pressure DOES NOT exceed
maximum 0.5 psig (14-in. wc) stated on gas valve. (See Fig. 45.)
Piping should be pressure tested in accordance with local and
national plumbing and gas codes before furnace has been attached.
In Canada, refer to current edition of NSCNGPIC. If pressure
exceeds 0.5 psig (14-in. wc), gas supply pipe must be disconnected
from furnace and capped before pressure test. If test pressure is
equal to or less than 0.5 psig (14-in. wc), close manual shut-off
valve located on gas valve before test. It is recommended that
ground joint union be loosened before pressure testing. After all
connections have been made, purge lines and check for leakage.
ELECTRICAL CONNECTIONS
See Fig. 22 for field wiring diagram showing typical field 115-v
and 24-v wiring. Check all factory and field electrical connections
for tightness.
Never purge a gas line into a combustion chamber. Never use
matches, candles, flame, or other sources of ignition for
purpose of checking leakage. Use a soap-and-water solution
to check for leakage. A failure to follow this warning could
result in fire, explosion, personal injury, or death.
Use proper length of pipe to avoid stress on gas control
manifold. Failure to follow this warning could result in a gas
leak resulting in fire, explosion, personal injury, or death.
Table 2—Maximum Capacity of Pipe*
NOMINAL
IRON
PIPE
SIZE
(IN.)
1/2
3/4
1
1-1/4
1-1/2
LENGTH OF PIPE (FT)
INTERNAL
DIAMETER
(IN.)
10
20
30
40
50
0.622
0.824
1.049
1.380
1.610
175
360
680
1400
2100
120
250
465
950
1460
97
200
375
770
1180
82
170
320
660
990
73
151
285
580
900
Blower access panel door switch opens 24-v power to control
center. No component operation can occur. The 115-v power
is still present at control center and transformer. Do not
bypass or close switch with panel removed. Failure to follow
this warning could result in personal injury or death.
* Cubic ft of gas per hr for gas pressures of 0.5 psig (14-in. wc) or less, and a
pressure drop of 0.5-in. wc (based on a 0.60 specific gravity gas). Ref: Table
10-2 NFPA 54-1992.
Furnace control must be grounded for proper operation or
control will lock out. Control is grounded through green wire
routed to gas valve and burner box screw.
Install a sediment trap in riser leading to furnace. Trap can be
installed by connecting a tee to riser leading to furnace so
straight-through section of tee is vertical. Then connect a capped
nipple into lower end of tee. Capped nipple should extend below
level of gas controls. Place a ground joint union between gas
control manifold and manual gas shut-off valve. (See Fig. 21.)
Step 1—115-v Wiring
Before proceeding with electrical connections, make certain that
voltage, frequency, and phase correspond to that specified on unit
rating plate. Also, check to be sure that service provided by utility
is sufficient to handle load imposed by this equipment. Refer to
rating plate or Table 3 for equipment electrical specifications.
Make all electrical connections in accordance with National
Electrical Code (NEC) ANSI/NFPA 70-1993 and any local codes
or ordinances that might apply. For Canadian installations, all
electrical connections must be made in accordance with Canadian
Electrical Code CSA C22.1 or subauthorities having jurisdiction.
If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at gas
valve and extend a minimum of 2 in. outside furnace casing.
An accessible manual shut-off valve MUST be installed upstream
of furnace gas controls and within 6 ft of furnace. A 1/8-in. NPT
plugged tapping, accessible for test gage connection, MUST be
installed immediately upstream of gas supply connection to
furnace and downstream of manual shut-off valve.
Use a separate, fused branch electrical circuit containing a properly
sized fuse or circuit breaker for this furnace. See Table 3 for wire
size and fuse specifications. A disconnecting means must be
located within sight from and readily accessible to furnace.
16
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
W
FOUR
WIRE
R
G
Y
THERMOSTAT
TERMINALS
FIELD-SUPPLIED
FUSED DISCONNECT
TWO-WIRE
HEATINGONLY
BLK
BLK
W
WHT
WHT
R
GND
GND
115-VOLT FIELD- AUXILIARY
J-BOX
SUPPLIED
CONTROL
FUSED
BOX
DISCONNECT
208/230- OR
460-VOLT
THREE
PHASE
G
C
GND
CONDENSING
UNIT
Y
24-VOLT
TERMINAL
BLOCK
FURNACE
208/230VOLT
SINGLE
PHASE
TWO
WIRE
NOTE: Connect Y-terminal as
shown for proper
operation.
NOTE: If any of the original wire,
as supplied, must be replaced, use
same type or equivalent wire.
A78461
Fig. 22—Heating and Cooling Application Wiring Diagram
Table 3—Electrical Data
UNIT
SIZE
VOLTS—
HERTZ—
PHASE
040-08
040-12
060-12
060-16
080-12
080-16
080-20
100-16
100-20
120-20
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
OPERATING
VOLTAGE RANGE
Max*
Min*
127
104
127
104
127
104
127
104
127
104
127
104
127
104
127
104
127
104
127
104
MAX
UNIT
AMPS
UNIT
AMPACITY†
MIN
WIRE
SIZE
MAX WIRE
LENGTH (FT)‡
MAX FUSE OR
CKT BKR AMPS**
6.1
7.3
7.1
9.5
7.6
10.0
14.1
10.2
14.8
14.6
8.4
10.0
9.8
12.8
10.4
13.4
18.4
13.5
19.3
19.1
14
14
14
14
14
14
12
14
12
12
38
37
38
29
36
28
31
27
30
30
15
15
15
15
15
15
20
15
20
20
* Permissible limits of voltage range at which unit will operate satisfactorily.
† Unit ampacity = 125 percent of largest operating component’s full load amps plus 100 percent of all other potential operating components’ (EAC, humidifier, etc.) full
load amps.
‡ Length shown is as measured 1 way along wire path between unit and service panel for maximum 2 percent voltage drop.
** Time-delay fuse is recommended.
The cabinet MUST have an uninterrupted or unbroken ground
according to NEC ANSI/NFPA 70-1993 and Canadian Electrical Code CSA C22.1 or local codes to minimize personal
injury if an electrical fault should occur. This may consist of
electrical wire or conduit approved for electrical ground when
installed in accordance with existing electrical codes. Do not
use gas piping as an electrical ground.
ELECTRIC
DISCONNECT
SWITCH
COPPER
WIRE ONLY
ALUMINUM
WIRE
J-Box Relocation
1. Remove 2 screws holding auxiliary J-box. (See Fig. 23.)
2. Rotate J-box 180° and attach box to right side, using holes
provided.
A93033
Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control center fault code indicator light will
flash rapidly and furnace will NOT operate.
17
Step 1—Removal of Existing Furnaces from
Common Vent Systems
If furnace being replaced was connected to a common vent system
with other appliances, these steps shall be followed with each
appliance remaining connected to common vent system placed in
operation, while other appliances remaining connected to common
vent system are not in operation:
1. Seal any unused openings in common vent system.
2. Visually inspect vent system for proper size and horizontal
pitch. Determine there is no blockage or restriction, leakage,
corrosion, and other deficiencies which could cause an unsafe
condition.
3. Insofar as is practical, close all building doors and windows
and all doors between space in which appliances remaining
connected to common vent system are located and other
spaces of building. Turn on clothes dryers and any appliance
not connected to common vent system. Turn on any exhaust
fans, such as range hoods and bathroom exhausts, so they
operate at maximum speed. Do not operate a summer exhaust
fan. Close fireplace dampers.
A93051
Fig. 23—Relocating J-Box
If manual disconnect switch is to be mounted on furnace,
select a location where a drill or fastener will not contact
electrical or gas components.
4. Follow lighting instructions and place appliance in operation.
Adjust thermostat so appliance operates continuously.
Step 2—24-v Wiring
5. Test for flue gas spillage at drafthood relief opening after 5
minutes of main burner operation. Use flame of a match or
candle, etc.
Make field 24-v thermostat connections at 24-v terminal block on
control center. For proper cooling operation, Y wire from thermostat MUST be connected to Y terminal on control center, as shown
in Fig. 22. The 24-v terminal board is marked for easy connection
of field wiring. (See Fig. 24.) The 24-v circuit contains a 3-amp,
automotive-type fuse located on control center. (See Fig. 25.) Any
electrical shorts of 24-v wiring during installation, service, or
maintenance may cause fuse to blow. If fuse replacement is
required, use only a fuse of identical size (3 amp).
6. After it has been determined that each appliance remaining
connected to common vent system properly vents when tested
as above, return doors, windows, exhaust fans, fireplace
dampers, any other gas burning appliances to their previous
condition of use.
7. If improper venting is observed during any of above tests,
common vent system must be corrected. Vent system or vent
connectors may need to be resized. For any other appliances
when resizing vent systems or vent connectors, system or
connector must be sized to approach minimum size as
determined using appropriate table found in Part 11 of NFGC
or Section 5 of NSCNGPIC.
NOTE: Use AWG No. 18 color-coded copper thermostat wire for
lengths up to 100 ft. For wire lengths over 100 ft, use AWG No.
16 wire.
Step 3—Accessories
1. Electronic Air Cleaner (EAC)
Step 2—Combustion-Air and Vent Piping
Two spring clamp terminals (for 12 gage maximum, solid or
stranded wire), marked EAC-1 and EAC-2, are provided for
EAC connection. (See Fig. 25.) These terminals are energized
with 115v (1.5-amp maximum) during blower motor operation. To connect EAC power leads to furnace control center,
strip approximately 1/8 in. of insulation from wire. Open
terminal by depressing switch arm with a screwdriver or
finger, and insert wire as shown in Fig. 26.
GENERAL
Combustion-air and vent pipe fittings must conform to American
National Standards Institute (ANSI) standards and American
Society for Testing and Materials (ASTM) standards D1785
(schedule-40 PVC), D2665 (PVC-DWV), D2241 (SDR-21 and
SDR-26 PVC), D2661 (ABS-DWV), F628 (schedule-40 ABS), or
F891 (PVC-DWV cellular core). Pipe cement and primer must
conform to ASTM standards D2564 (PVC) or D2235 (ABS). See
Table 5 for maximum pipe lengths and Fig. 31, 32, 33, 34, and 35
for exterior piping arrangements.
2. Humidifier (HUM)
Screw terminals (HUM and Com) are provided for 24-v
humidifier connection. (See Fig. 24.) HUM terminal is energized with 24v (0.5-amp maximum) after inducer motor
prepurge period.
In Canada construct all combustion-air and vent pipes for this unit
of CSA or c-UL certified schedule-40 PVC, PVC-DWV or
ABS-DWV pipe and pipe cement. SDR pipe is NOT approved in
Canada.
NOTE: A field-supplied, 115-v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.
NOTE: Furnace combustion-air and vent pipe connections are
sized for 2-in. pipe. Any pipe size change should be made outside
furnace casing in vertical pipe. (See Fig. 27.) This allows proper
drainage of vent condensate.
DIRECT VENTING
The 58MCA and 58MXA Furnaces require a dedicated (one
58MCA or one 58MXA furnace only) direct vent system. In a
direct vent system, all air for combustion is taken directly from
outside atmosphere, and all flue products are discharged to outside
atmosphere.
Combustion-air and vent pipes must terminate together in same
atmosphere pressure zone, either through roof or sidewall (roof
termination preferred), using accessory termination kit. See Table
4 for required clearances.
18
19
GV
GVR
HI/LO
HSI
HSIR
HUM
IDM
IDR
ILK
JB
LED
LGPS
LS
OL
PCB
BLWR
BLWM
CAP
CPU
EAC-1
EAC-2
FRS
FSE
FU1
FU2
1
BLK
GRN
M
IDM
BRN
AUX
OL
CAP -2
EAC-2
COM
EAC-1
HEAT SPARE-2
BRN
WHT
PR2
L2
COOL SPARE-1
24 VAC-3A
FU1 FUSE
BLOWER
SPEED
SELECT
1 2 3 PL4
PL5
2
HSI
PL3
1
2
3
6 5 4
9 8 7
LED
G
R
Y
W
COM
HUM
SEC-1 SEC-2
WHT
PL1 3 2 1
TEST/TWIN
HI/LO
RELAY
BLWR
PL2
1
2
IDR
GVR
SW2
ILK
WHT
RED
PRS
RED
BLU
PL1
PL2
PL3
PL4
PL5
PRS
SW1 & 2
TEST/TWIN
TRAN
BLK
OL
LS
RED
WHT
WHT (COM)
RED (LO)
BLU (MED LO)
YEL (MED HI)
NOTE #8
BLK (HI)
RED
ORN
BLOWER MOTOR RELAY, SPST-(N.O.)
BLOWER MOTOR
CAPACITOR
MICROPROCESSOR AND CIRCUITRY
ELECTRONIC AIR CLEANER CONNECTION (115 VAC 1.5 AMP MAX.)
ELECTRONIC AIR CLEANER CONNECTION (COMMON)
FLAME ROLLOUT SW. -MANUAL RESET, SPST-(N.C.)
FLAME PROVING ELECTRODE
FUSE, 3 AMP, AUTOMOTIVE BLADE TYPE, FACTORY INSTALLED
FUSE OR CIRCUIT BREAKER CURRENT INTERRUPT DEVICE
(FIELD INSTALLED & SUPPLIED)
GAS VALVE-REDUNDANT OPERATORS
GAS VALVE RELAY, DPST-(N.O.)
BLOWER MOTOR SPEED CHANGE RELAY, SPDT
HOT SURFACE IGNITOR (115 VAC)
HOT SURFACE IGNITOR RELAY, SPST-(N.O.)
24VAC HUMIDIFIER CONNECTION (.5 AMP. MAX.)
INDUCED DRAFT MOTOR
INDUCED DRAFT RELAY, SPST-(N.O.)
BLOWER ACCESS PANEL INTERLOCK SWITCH, SPST-(N.O.)
JUNCTION BOX
LIGHT-EMITTING DIODE FOR STATUS CODES
LOW GAS PRESSURE SWITCH, SPST-(N.O.)
LIMIT SWITCH, AUTO RESET, SPST(N.C.)
AUTO-RESET INTERNAL MOTOR OVERLOAD TEMP. SW.
PRINTED CIRCUIT BOARD
LEGEND
BLK
120 VAC
L1 PR1
BLK
BLK
HSIR
BLK
SEC
SEC
SEC
SEC
GRN
WHT
90
135
180
225
BLOWER OFF DELAY
SELECTION CHART
WHT
PCB
WHT
BLOWER
OFF
DELAY SW1
1.5 AMP
WHT
BLK
FU2
NEUTRAL
L1
FUSED DISCONNECT
SWITCH (WHEN REQ’D)
NOTE #4
HSIR
1
TRAN
IDR
CPU
BLWR
GVR
GVR-1
HI/LO
SEC-2
24VAC
SEC-1
GVR-2
1
1
9
6
5
1
2
IDM
AUX
1-M
3-P
LS
(WHEN USED)
FSE
NOTE #5
2-C
GV
NOTE #6
PRS
LGPS
PL1
M
OL
BRN
3 BRN
PL4 CAP -2
HSI
FRS
PL3
8
2
3
4
1
7
2
3
PL2 2 PL5 2
PR1 115VAC PR2
EAC-2
CAP-1
BLWM
START
L2
SCHEMATIC DIAGRAM
(NATURAL GAS & PROPANE)
A93050
1. IF ANY OF THE ORIGINAL EQUIPMENT WIRE IS REPLACED USE WIRE RATED FOR 105°C.
2. INDUCER (IDM) AND BLOWER (BLWM) MOTORS CONTAIN INTERNAL AUTO-RESET THERMAL
OVERLOAD SWITCHES (OL).
3. BLOWER MOTOR SPEED SELECTIONS ARE FOR AVERAGE CONDITIONS, SEE INSTALLATION
INSTRUCTIONS FOR DETAILS ON OPTIMUM SPEED SELECTION.
4. USE ONLY COPPER WIRE BETWEEN THE DISCONNECT SWITCH AND THE
FURNACE JUNCTION BOX (JB).
5. THIS WIRE MUST BE CONNECTED TO FURNACE SHEETMETAL FOR CONTROL TO PROVE FLAME.
6. FACTORY CONNECTED WHEN LGPS NOT USED.
7. REPLACE ONLY WITH A 3 AMP FUSE.
8. YELLOW LEAD NOT ON ALL MOTORS.
9. BLOWER-ON DELAY, GAS HEATING 60 SECONDS, COOLING OR HEAT PUMP 2 SECONDS.
10. BLOWER-OFF DELAY, GAS HEATING 90, 135, 180 OR 225 SECONDS, COOLING OR HEAT PUMP 90 SECONDS.
11. IGNITION-LOCKOUT WILL OCCUR AFTER FOUR CONSECUTIVE UNSECCESSFUL
320700-401 REV. H
TRIALS-FOR-IGNITION. CONTROL WILL AUTO-RESET AFTER THREE HOURS.
NOTES:
COM
G
Y
W
R
HUM
IDR
HSIR
BLWR
FU1 NOTE #7
ILK
TEST/TWIN
L1
SPARE-1
HEAT
EQUIPMENT GROUND
LO
MED LO
MED HI
HI
SPARE-2
HI/LO
OL
NOTE #8
COOL
COM
COM
EAC-1
L1 NEUTRAL
NOTE #4
TO 115VAC FIELD DISCONNECT
→ Fig. 24—Wiring Diagram
PLUG RECEPTACLE
FIELD SPLICE
EQUIPMENT GROUND
FIELD GROUND
FIELD WIRING SCREW TERMINAL
CONDUCTOR ON PCB
FIELD WIRING (24VAC)
FIELD WIRING (115VAC)
FACTORY WIRING (24VAC)
FACTORY WIRING (115VAC)
PCB TERMINAL
UNMARKED TERMINAL
JUNCTION
9-CIRCUIT CONNECTOR
2-CIRCUIT PCB CONNECTOR
3-CIRCUIT IDM CONNECTOR
3-CIRCUIT IDM EXTENSION CONNECTOR
2-CIRCUIT HSI/PCB CONNECTOR
PRESSURE SWITCH, SPST-(N.O.)
BLOWER OFF DELAY
COMPONENT TEST & TWIN TERMINAL
TRANSFORMER-115VAC/24VAC
GRN
BRN
CAP -1
NOTE #5
2-C
GV
3-P
YEL
WHT (COM)
GRN
WHT
BRN
JB
BLWM
START
GRN
BLK
FSE
RED
FRS
1-M
NOTE #6
BLU
(WHEN USED)
LGPS
TRAN
BLOWER OFF DELAY
ADJUSTMENT SWITCH
G
24V THERMOSTAT
TERMINALS
R
Y
W
Com
TEST/TWIN
24V
HUM
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX)
LED OPERATION &
DIAGNOSTIC LIGHT
HARNESS CONNECTOR
SEC-1
24V TRANSFORMER SEC-2
3-AMP FUSE
SPARE 1
COOL
HEAT
BLOWER SPEED
SELECTION TERMINALS
SPARE 2
EAC 1 (BLACK)
EAC-ELECTRONIC AIR CLEANER
TERMINALS (115-VAC 1 AMP MAX)
115-VAC (L1)
POWER
SUPPLY
HOT SURFACE
IGNITOR
CONNECTOR
EAC 2 (WHITE)
115-VAC (L2) NEUTRAL
CONNECTION
INDUCER MOTOR
CONNECTOR
A93052
Fig. 25—Control Center
FURNACE
NOT IN
HORIZONTAL
SECTION
PIPE DIAMETER
TRANSITION IN
VERTICAL SECTION
A93034
Fig. 27—Combustion-Air and Vent Pipe Diameter
Transition Location and Elbow Configuration
A93053
Fig. 26—EAC Terminals on Control Center
Furnace combustion-air and vent pipe connections must be attached as shown in Fig 28. Combustion-air intake plug fitting and
inducer housing alternate vent cap may need to be relocated in
some applications.
When vent pipe is exposed to temperatures below freezing,
such as when it passes through an unheated space or when a
chimney is used as a raceway, pipe must be insulated as
shown in Table 6 with Armaflex-type insulation.
When combustion-air pipe is installed above a suspended
ceiling, pipe must be insulated with 3/8-in. thick Armaflextype insulation. Combustion-air pipe should also be insulated
when it passes through warm, humid space.
20
Table 4–Combustion-Air and Vent Pipe
Termination Clearances
LOCATION
Above grade level or above
anticipated snow depth
Dryer vent
From plumbing vent stack
From any mechanical fresh air
intake
For furnaces with an input capacity less than 100,000 Btuh–from any non-mechanical air
supply (windows or doors
which can be opened) or
combustion-air opening
For furnaces with an input capacity greater than 100,000
Btuh–from any nonmechanical air supply (windows or doors which can be
opened) or combustion-air
opening
From service regulator vent,
electric and gas meters, and
relief equipment
Above grade when adjacent to
public walkway
Combustion air must not be taken from inside structure
because inside air is frequently contaminated by halogens,
which include fluorides, chlorides, bromides, and iodides.
These elements are found in aerosols, detergents, bleaches,
cleaning solvents, salts, air fresheners, adhesives, paint, and
other household products. Locate combustion-air inlet as far
as possible from swimming pool and swimming pool pump
house.
Excessive exposure to contaminated combustion air will
result in safety and performance related problems.
CLEARANCE (FT)
U.S.A.
Canada
1
1†
3
3
3
3
1
6
1
1
Solvent cements are combustible. Keep away from heat,
sparks, and open flame. Use only in well-ventilated areas.
Avoid breathing in vapor or allowing contact with skin or
eyes. Failure to follow this warning could result in fire,
property damage, personal injury, or death.
1
3
4*
6‡
7
7
All combustion-air and vent pipes must be airtight and
watertight. Pipes must also terminate exactly as shown in Fig.
31, 32, 33, 34, or 35. Failure to follow this warning could
result in property damage, personal injury, or death.
* Horizontal distance.
† 18 in. above roof surface in Canada.
‡ 36 in. to electric meter in Canada only.
NOTES:
1. If installing 2 adjacent 58MCA or 58MXA Furnaces, refer to Multi-Venting
and Vent Terminations section for proper vent configurations.
2. When locating combustion-air and vent terminations, consideration must be
given to prevailing winds, location, and other conditions which may cause
recirculation of the appliance’s own flue products or the flue products of
adjacent vents. Recirculation can cause poor combustion, inlet condensate
problems, and accelerated corrosion of heat exchangers.
NOTE: The minimum combustion-air and vent pipe length (each)
for these furnaces is 5 ft. Short pipe lengths (5-8 ft) may discharge
water droplets. These droplets may be undesirable, and a 12-in.
minimum horizontal pipe section is recommended, as shown in
Fig. 29, to reduce excessive droplets from exiting vent pipe outlet.
COMBUSTION-AIR AND VENT PIPE DIAMETER
Determine combustion-air and vent pipe diameter.
1. Using Table 5, determine preliminary combustion-air pipe
diameter.
2. Using Table 5, determine preliminary vent pipe diameter.
3. Use largest diameter pipe determined in 1. and 2. above for
both pipes.
NOTE: Do not count elbows or pipe sections in terminations or
within furnace. See shaded areas in Fig. 31, 32, 33, 34, and 35.
EXAMPLE:
An 080-12 size furnace located in Indianapolis, elevation 650 ft
above sea level, could be installed in an application requiring 3
elbows and 32 ft of vent pipe, along with 5 elbows and 34 ft of
combustion-air pipe. Table 5 indicates this application would
allow a 2-in. diameter vent pipe, but require a 2-1/2 in. diameter
combustion air pipe (2-in. pipe is good for 35 ft with 3 elbows,
but only 30 ft with 5 elbows). Therefore, 2-1/2 in. diameter pipe
must be used for both vent and combustion-air pipes since
larger required diameter must always be used for both pipes. If
same installation were in Albuquerque, elevation 5250 ft above
sea level, installation would require 2-1/2 in. vent pipe and
combustion-air pipe. At 5001- to 6000-ft elevation, 2-in. pipe is
only good for 17 ft with 5 elbows, and 2-1/2 in. pipe is good for
70 ft with 5 elbows.
A93083
COMBUSTION-AIR AND VENT PIPE ATTACHMENT
Fig. 28—Combustion-Air and Vent Pipe
Connections
NOTE: All pipe joints must be watertight except attachment of
combustion-air pipe to inlet housing connection, since it may be
necessary to remove pipe for servicing.
1. Attach combustion-air pipe as follows:
21
12″ MIN
12″ MIN
VENT PIPE
VENT PIPE
COMBUSTION-AIR PIPE
HORIZONTAL TO ROOF
COMBUSTION-AIR PIPE
HORIZONTAL TO SIDEWALL
COMBUSTION-AIR PIPE
VENT PIPE
COMBUSTION-AIR PIPE
12″ MIN
12″ MIN
VENT PIPE
VERTICAL TO ROOF
VERTICAL TO SIDEWALL
NOTE: A 12-in. minimum horizontal pipe section is recommended with
short (5 to 8 ft) vent systems. This recommendation is to reduce
excessive condensate droplets from exiting the vent pipe.
A93591
Fig. 29—Short Vent (5 to 8 Ft) System
a. Determine location of combustion-air intake pipe connection to combustion-air intake housing as shown in Fig. 28
for application.
COMBUSTION-AIR INTAKE HOUSING PLUG
FITTING
The combustion-air intake plug fitting must be installed in
unused combustion-air intake housing. This fitting must be
attached by using RTV sealant, or by drilling a 1/8-in. hole in
fitting, using hole in intake housing as a guide. Install a
field-supplied No. 6 or No. 8 sheet metal screw.
NOTE: DO NOT OVERTIGHTEN SCREW. Breakage to intake
housing or fitting may cause air leakage to occur.
A plugged drain connection has been provided on this fitting
for use when moisture is found in combustion-air intake pipe
and combustion box.
NOTE: Moisture in combustion-air intake may be result of
improper termination. Ensure combustion-air intake pipe is similar
to that shown in Fig. 31, 32, 33, 34, or 35 so it will not be
susceptible to areas where light snow or other sources of moisture
could be pulled in.
If use of this drain connection is desired, drill out fitting’s tap
plug with a 3/16-in. drill and connect a field-supplied 3/8-in.
tube. This tube should be routed to open condensate drain for
furnace and A/C (if used), and should be trapped. (See Fig.
30.)
2. Attach vent pipe as follows:
b. Reposition combustion-air intake housing plug fitting in
appropriate unused intake housing connection.
c. Insert perforated disk assembly (factory supplied in loose
parts bag) in intake housing where combustion-air intake
pipe will be connected.
d. Install pipe support (factory supplied in loose parts bag)
into selected furnace casing combustion-air pipe hole. Pipe
support should be positioned at bottom of casing hole.
e. Insert 2-in. diameter pipe into intake housing.
NOTE: A 2-in. diameter pipe must be used within the furnace
casing. Make all pipe diameter transitions outside furnace casing.
f. Drill a 1/8-in. hole in 2-in. combustion-air pipe using hole
in intake housing as a guide.
g. Install a field-supplied No. 6 or No. 8 sheet metal screw
into combustion-air pipe.
NOTE: DO NOT OVERTIGHTEN SCREW. Breakage to intake
housing or fitting may cause air leakage to occur.
NOTE: Do not attach combustion-air intake pipe permanently to
combustion-air intake housing since it may be necessary to remove
pipe for service of ignitor or flame sensor.
22
Table 5—Maximum Allowable Pipe Length (Ft)
ALTITUDE
0 to 2000
2001 to 3000
3001 to 4000
4001 to 5000‡
5001 to 6000‡
UNIT SIZE
TERMINATION
TYPE
PIPE
DIAMETER
(IN.)*
1
1-1/2
2
1-1/2
2
1-1/2
2
2-1/2
2
2-1/2
3
2-1/2 one disk
3 one disk
3† one disk
3† no disk
1-1/2
2
1-1/2
2
1
2
3
4
5
6
5
70
70
20
70
10
55
70
5
40
70
10
35
35
70
67
70
17
70
NA
70
70
15
70
NA
50
70
NA
30
70
NA
30
35
70
62
70
12
67
NA
65
70
10
70
NA
35
70
NA
20
70
NA
15
35
70
57
70
7
66
NA
60
70
5
70
NA
30
70
NA
20
70
NA
NA
30
70
52
70
NA
61
NA
60
70
NA
70
NA
30
70
NA
10
70
NA
NA
30
70
52
70
NA
61
NA
55
70
NA
70
NA
20
70
NA
NA
70
NA
NA
30
70
47
70
NA
61
2
49
44
30
25
25
15
2-1/2
70
70
70
70
70
70
35
70
31
31
63
64
70
16
68
26
70
26
30
62
59
70
11
63
16
70
12
30
62
54
70
6
62
16
70
NA
25
61
49
70
NA
57
6
66
NA
25
61
48
70
NA
57
NA
61
NA
24
61
43
70
NA
56
NUMBER OF 90° ELBOWS
040-08
040-12
2 Pipe or 2-In.
Concentric
060-12
060-16
2 Pipe or 2-In.
Concentric
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
100-16
100-20
2 Pipe or 3-In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
040-08
040-12
2 Pipe or 2-In.
Concentric
060-12
060-16
2 Pipe or 2-In.
Concentric
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
100-16
100-20
2 Pipe or 3-In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
040-08
040-12
2 Pipe or 2-In.
Concentric
060-12
060-16
2 Pipe or 2-In.
Concentric
2-1/2
3
3 one disk
3† one disk
3† no disk
1-1/2
2
1-1/2
2
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
2
46
41
28
23
22
13
2-1/2
70
70
70
70
70
70
100-16
100-20
2 Pipe or 3-In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
040-08
040-12
2 Pipe or 2-In.
Concentric
060-12
060-16
2 Pipe or 2-In.
Concentric
2-1/2
3
3 one disk
3† one disk
3† no disk
1-1/2
2
1-1/2
2
33
70
29
29
59
60
70
15
64
24
70
24
28
59
55
70
10
59
15
70
10
28
58
50
70
5
58
14
66
NA
23
57
45
70
NA
53
5
61
NA
22
57
44
70
NA
52
NA
56
NA
21
56
39
70
NA
52
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
2
44
39
26
21
20
11
2-1/2
70
70
70
70
70
70
100-16
100-20
2 Pipe or 3-In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
040-08
040-12
2 Pipe 2-In.
Concentric
060-12
060-16
2 Pipe or 2-In.
Concentric
2-1/2
3
3† one disk
3† no disk
1-1/2
2
1-1/2
2
31
70
27
56
57
70
14
60
22
70
26
55
52
70
9
55
13
67
26
54
47
70
NA
54
12
62
21
53
42
70
NA
49
NA
57
20
52
40
70
NA
48
NA
52
19
52
35
70
NA
47
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
2
41
36
23
18
17
8
2-1/2
70
70
70
70
70
70
100-16
100-20
2 Pipe or 3-In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
2-1/2
3
3† one disk
3† no disk
29
70
26
53
21
67
24
52
12
62
23
50
11
57
18
49
NA
52
17
48
NA
47
16
47
23
ALTITUDE
6001 to 7000‡
7001 to 8000‡
8001 to 9000‡
9001 to 10,000‡
UNIT SIZE
TERMINATION
TYPE
040-08
040-12
2 Pipe or 2-In.
Concentric
060-12
060-16
2 Pipe or 2-In.
Concentric
PIPE
DIAMETER
(IN.)*
1-1/2
2
1-1/2
2
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
2
38
33
21
16
15
6
2-1/2
70
70
68
67
66
64
100-16
100-20
2 Pipe or 3-In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
040-08
040-12
2 Pipe or 2-In.
Concentric
060-12
060-16
2 Pipe or 2-In.
Concentric
2-1/2
3
3† one disk
3† no disk
1-1/2
2
1-1/2
2
27
68
24
49
49
66
12
53
19
63
22
48
44
65
7
48
10
58
21
47
39
63
NA
46
9
53
16
45
34
62
NA
41
NA
48
15
44
33
60
NA
40
NA
43
13
43
28
59
NA
38
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
2
36
31
19
14
12
NA
2-1/2
66
65
63
62
60
59
2-1/2
3
3† one disk
3† no disk
1-1/2
2
1-1/2
2
25
63
22
46
46
62
11
49
17
58
20
44
41
60
6
44
8
53
19
43
36
58
NA
42
7
48
14
41
31
56
NA
37
NA
43
12
40
29
55
NA
35
NA
38
11
38
24
53
NA
34
2
33
28
17
12
10
NA
2-1/2
62
60
58
56
55
53
2-1/2
3
3† one disk
3† no disk
1-1/2
2
23
59
20
43
42
57
15
54
18
41
37
55
7
49
17
39
32
53
5
44
12
37
27
51
NA
39
10
35
25
49
NA
34
8
34
20
47
2
45
40
38
33
31
29
2
30
25
14
9
7
NA
2-1/2
57
55
53
51
49
47
2-1/2
3
3† one disk
3† no disk
21
54
18
39
13
49
16
37
5
44
14
35
NA
39
9
33
NA
34
7
31
NA
29
5
29
100-16
100-20
2 Pipe or 3 In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
040-08
040-12
2 Pipe or 2-In.
Concentric
060-12
060-16
2 Pipe or 2-In.
Concentric
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
100-16
100-20
2 Pipe or 3-In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
040-08
040-12
2 Pipe or 2-In.
Concentric
060-12
060-16
080-12
080-16
080-20
2 Pipe or 2-In.
Concentric
2 Pipe or 2-In.
Concentric
100-16
100-20
2 Pipe or 3-In.
Concentric
120-20
2 Pipe or 3-In.
Concentric
NUMBER OF 90° ELBOWS
1
2
3
4
5
6
53
70
13
57
48
70
8
52
43
68
NA
50
38
67
NA
45
37
66
NA
44
32
64
NA
43
* Disk usage—Unless otherwise specified, use perforated disk assembly (factory supplied in loose parts bag). If stated, unsnap 1/2 perforated disk assembly and use
shouldered disk half or no disk assembly.
† Wide radius elbow.
‡ Vent sizing for Canadian installations over 4500 ft (1370 m) above sea level are subject to acceptance by the local authorities having jurisdiction.
NA—Not Allowed; pressure switch will not make.
NOTES:
1. Do not use pipe size greater than those specified in table or incomplete combustion, flame disturbance, or flame sense lockout may occur.
2. Size both the combustion-air and vent pipe independently, then use the larger diameter for both pipes.
3. Assume two 45° elbows equal one 90° elbow. Long radius elbows are desirable and may be required in some cases.
4. Elbows and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
5. The minimum pipe length is 5 ft for all applications.
a. Determine location of vent pipe connection to inducer
housing as shown in Fig. 28 for application.
b. Reposition neoprene inducer housing outlet cap and clamp
to appropriate unused inducer housing connection. Tighten
clamp.
Inducer housing outlet cap must be installed and fully seated
against inducer housing. Clamp must be tightened to prevent
any condensate leakage. Failure to follow this warning could
result in electrical shock, fire, personal injury, or death.
c. Install pipe support (factory supplied in loose parts bag)
into selected furnace casing vent pipe hole. Pipe support
should be positioned at bottom of casing hole.
24
13. Slope combustion-air and vent pipes toward furnace a minimum of 1/4 in. per linear ft with no sags between hangers.
COMBUSTION – AIR
INTAKE HOUSING
3/8" ID TUBE
BURNER
BOX
14. Use appropriate methods to seal openings where vent and
combustion-air pipes pass through roof or side wall.
Step 3—Concentric Vent and Combustion-Air
Termination Kit Installation
3/16"
DRILL
TRAP
NOTE: If these instructions differ from those packaged with
termination kit, follow kit instructions.
COMBUSTION –
AIR PIPE
Combustion-air and vent pipes must terminate outside structure. A
factory accessory termination kit must be installed in 1 of the
installations shown in Fig. 31, 32, 33, 34, or 35. Four termination
kits are available.
4″
MIN
TO OPEN
DRAIN
1. The 2-in. termination bracket kit is for 1-in., 1-1/2 in., and
2-in. diameter 2-pipe termination systems.
A93035
Fig. 30—Intake Housing Plug Fitting Drain
2. The 3-in. termination bracket kit is for 2-1/2 in. and 3-in.
diameter 2-pipe termination systems.
d. Insert 2-in. diameter pipe into inducer housing through
neoprene coupling and clamp in inducer housing. Tighten
clamp.
3. The 2-in. concentric vent/air termination kit is for 1-in., 1-1/2
in., 2-in., and 2-1/2 in. diameter pipe systems when single
penetration of wall or roof is desired.
4. The 3-in. concentric vent/air termination kit is for 2-1/2 in. and
3-in. diameter pipe systems when single penetration of wall or
roof is desired.
Vent pipe must be installed and fully seated against inducer
housing. Clamp must be tightened to prevent any condensate
leakage. Failure to follow this warning could result in
electrical shock, fire, personal injury, or death.
NOTE: Shaded parts in Fig. 31, 32, 33, 34, and 35 are considered
to be termination. These components should NOT be counted
when determining pipe diameter. Roof termination is preferred
since it is less susceptible to damage, has reduced chances to intake
contaminants, and has less visible vent vapors. (See Fig. 31 or 32.)
Sidewall termination may require sealing or shielding of building
surfaces with a corrosive resistance material due to corrosive
combustion products of vent system.
NOTE: A 2-in. diameter pipe must be used within the furnace
casing. Make all pipe diameter transitions outside furnace casing.
VENT EXTENSION PIPE
Some furnaces are supplied with a PVC vent extension pipe
(2-in. diameter by 12-in. long). This pipe has a built-in
channel to assist vent condensate disposal. When this vent
extension pipe is supplied, it must be used to connect the field
vent pipe to furnace inducer housing on ALL upflow and
downflow applications.
NOTE: See label on vent extension pipe for proper installation.
This pipe may be shortened if an elbow is used to connect vent
extension tube to field-installed vent pipe.
EXTENDED EXPOSED SIDEWALL PIPES
Sidewall combustion-air and vent pipe terminations may be
extended beyond area shown in Fig. 34 or 35 in outside ambient by
insulating pipes as indicated in Table 6.
1. Determine combustion-air and vent pipe diameters, as stated
above, using total pipe length and number of elbows.
2. Using winter design temperature (used in load calculations),
find appropriate temperature for your application and furnace
model.
3. Working from furnace to outside, cut pipe to required
length(s).
4. Deburr inside and outside of pipe.
3. Determine required insulation thickness for exposed pipe
lengths.
5. Chamfer outside edge of pipe for better distribution of primer
and cement.
NOTE: Pipe length (ft) specified for maximum pipe lengths
located in unconditioned spaces cannot exceed total allowable pipe
length as specified in Table 5.
6. Clean and dry all surfaces to be joined.
7. Check dry fit of pipe and mark insertion depth on pipe.
NOTE: It is recommended that all pipes be cut, prepared, and
preassembled before permanently cementing any joint.
TWO-PIPE TERMINATION KIT
1. Determine location for termination.
8. After pipes have been cut and preassembled, apply generous
layer of cement primer to pipe fitting socket and end of pipe
to insertion mark. Quickly apply approved cement to end of
pipe and fitting socket (over primer). Apply cement in a light,
uniform coat on inside of socket to prevent buildup of excess
cement. Apply second coat.
Consideration of the following should be made when determining an appropriate location for termination kit.
a. Comply with all clearance requirements as stated in Table
4.
b. Termination kit should be positioned where vent vapors
will not damage plants/shrubs or air conditioning equipment.
9. While cement is still wet, twist pipe into socket with 1/4 turn.
Be sure pipe is fully inserted into fitting socket.
11. Handle pipe joints carefully until cement sets.
c. Termination kit should be positioned so that it will not be
affected by wind eddy (such as inside building corners) or
allow recirculation of flue gases, airborne leaves, or light
snow.
12. Support combustion-air and vent piping a minimum of every
5 ft (3 ft for SDR-21 or -26 PVC) using perforated metal
hanging strap.
d. Termination kit should be positioned where it will not be
damaged by or subjected to foreign objects, such as stones,
balls, etc.
10. Wipe excess cement from joint. A continuous bead of cement
will be visible around perimeter of a properly made joint.
25
ROOF
18″ MAXIMUM
BRACKET
COUPLING
COMBUSTION
AIR
VERTICAL SEPARATION
BETWEEN COMBUSTION
AIR AND VENT
VENT
8 3/4″ FOR 3″ KIT
6 3/4″ FOR 2″ KIT
MAINTAIN 12 IN. MINIMUM
CLEARANCE ABOVE HIGHEST
ANTICIPATED SNOW LEVEL.
MAXIMUM OF 24 IN. ABOVE ROOF.
A87224
OVERHANG OR ROOF
Fig. 31—Roof Termination (Preferred)
12″ MINIMUM
VENT
1″ MAXIMUM
COMBUSTION-AIR
VENT
COMBUSTION
AIR
MAINTAIN 12 IN.
(18 IN. FOR CANADA)
MINIMUM CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL. MAXIMUM OF
24 IN. ABOVE ROOF.
MAINTAIN 12 IN.
CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
GREATER.
A93054
A93055
Fig. 32—Concentric Vent and Combustion-Air Roof
Termination (Preferred)
Fig. 33—Concentric Vent and Combustion-Air Side
Termination
OVERHANG OR ROOF
OVERHANG OR ROOF
12″ MINIMUM
12″ MINIMUM
VENT
VENT
90°
BRACKET
COUPLING
90°
BRACKET
12 IN. SEPARATION
BETWEEN BOTTOM OF
COMBUSTION AIR AND
BOTTOM OF VENT
MAINTAIN 12 IN.
CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
GREATER.
COMBUSTION-AIR
(ELBOW PARALLEL
TO WALL)
A87226
12 IN. SEPARATION
BETWEEN BOTTOM OF
COMBUSTION AIR AND
BOTTOM OF VENT
MAINTAIN 12 IN.
CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
GREATER.
COMBUSTION-AIR
A87225
Fig. 34—Sidewall Termination of 12 in. or More
Fig. 35—Sidewall Termination of Less than 12 in.
26
Table 6—Maximum Allowable Exposed Vent Pipe Length (Ft) With Insulation in Winter Design
Temperature Ambient*
UNIT
SIZE
040
060
080
100
120
WINTER DESIGN
TEMPERATURE
(°F)
20
0
-20
20
0
-20
20
0
-20
20
0
-20
20
0
-20
INSULATION THICKNESS (IN.)†
MAX PIPE
DIAMETER
0
3/8
1/2
3/4
1
1-1/2
1-1/2
1-1/2
2
2
2
2-1/2
2-1/2
2-1/2
3
3
3
3
3
3
31
16
9
45
25
16
55
31
20
61
33
20
70
40
26
56
34
23
70
51
36
70
61
43
70
65
45
70
70
55
63
39
27
70
58
42
70
69
49
70
70
52
70
70
64
70
47
34
70
70
51
70
70
61
70
70
65
70
70
70
70
54
39
70
70
60
70
70
70
70
70
70
70
70
70
* Pipe length (ft) specified for maximum pipe lengths located in unconditioned spaces. Pipes located in unconditioned space cannot exceed total allowable pipe length
as specified in Table 5.
† Insulation thickness based on R value of 3.5 per in.
e. Termination kit should be positioned where vent vapors are
not objectionable.
2. Cut one 4-in. diameter hole for 2-in. kit, or one 5-in. diameter
hole for 3-in. kit.
2. Cut 2 holes, 1 for each pipe, of appropriate size for pipe size
being used.
3. Loosely assemble concentric vent/air termination components
together using instructions in kit.
3. Loosely install elbow in bracket and place assembly on
combustion-air pipe.
4. Slide assembled kit with rain shield REMOVED through hole.
NOTE: Do not allow insulation or other materials to accumulate
inside of pipe assembly when installing it through hole.
Roof terminations—Loosely install pipe coupling on properly cut vent pipe. Coupling must be positioned so bracket will
mount as shown in Fig. 31.
For applications using combustion-air pipe option, indicated
by dashed lines in Fig. 31, install 90° street elbow into 90°
elbow, making U-fitting. A 180° U-fitting may be used.
Sidewall terminations—Install bracket as shown in Fig. 34 or
35.
For applications using vent pipe option indicated by dashed
lines in Fig. 34, rotate vent elbow 90° from position shown in
Fig. 34.
4. Disassemble loose pipe fittings. Clean and cement using same
procedures as used for system piping.
Roof terminations—Locate assembly through roof to appropriate height as shown in Fig. 32.
Sidewall terminations—Locate assembly through sidewall
with rain shield positioned no more than 1-in. from wall as
shown in Fig. 33.
5. Disassemble loose pipe fittings. Clean and cement using same
procedures as used for system piping.
6. Check required dimensions as shown in Fig. 32 or 33.
Step 4—Multiventing and Vent Terminations
When 2 or more 58MCA or 58MXA Furnaces are vented near
each other, each furnace must be individually vented. NEVER
common vent or breach vent 58MCA or 58MXA furnaces. When
2 or more 58MCA or 58MXA furnaces are vented near each other,
2 vent terminations may be installed as shown in Fig. 36, 37, 38,
39, or 40, but next vent termination must be at least 36 in. away
from first 2 terminations. It is important that vent terminations be
made as shown to avoid recirculation of flue gases. Dimension "A"
in Fig. 36, 37, 38, 39, and 40 represents distance between pipes or
rain shields, as touching or 2-in. maximum separation.
5. Check required dimensions as shown in Fig. 31, 34, or 35.
CONCENTRIC VENT/AIR TERMINATION KIT
1. Determine location for termination.
Consideration of the following should be made when determining an appropriate location for termination kit.
a. Comply with all clearance requirements as stated in Table
4.
CONDENSATE DRAIN
b. Termination kit should be positioned where vent vapors
will not damage plants/shrubs or air conditioning equipment.
Step 1—General
Condensate trap is shipped installed in the blower shelf and factory
connected for UPFLOW applications. Condensate trap must be
RELOCATED for use in DOWNFLOW and HORIZONTAL
applications.
c. Termination kit should be positioned so it will not be
affected by wind eddy (such as inside building corners) or
that may allow recirculation of flue gases, airborne leaves,
or light snow.
Condensate trap MUST be used for all applications.
An external trap is not required when connecting the field drain to
this condensate trap.
d. Termination kit should be positioned where it will not be
damaged by or subjected to foreign objects, such as stones,
balls, etc.
The field drain connection (condensate trap or drain tube coupling)
is sized for 1/2-in. CPVC, 1/2-in. PVC, or 5/8-in. ID tube
connection.
e. Termination kit should be positioned where vent vapors are
not objectionable.
27
A
A85182
Fig. 36–Rooftop Termination (Dimension "A" is Touching or 2-In. Maximum Separation)
VENT
VENT
1″ MAXIMUM
(TYP)
A
COMBUSTION AIR
VENT
COMBUSTION
AIR
A
VENT
A93056
A93057
Fig. 37—Concentric Vent and Combustion-Air Roof
Termination (Dimension "A" is Touching or
2-In. Maximum Separation)
Fig. 38—Concentric Vent and Combustion-Air Side
Termination (Dimension "A" is Touching or
2-In. Maximum Separation)
VENT
VENT
COMBUSTION AIR
COMBUSTION AIR
COMBUSTION AIR
COMBUSTION AIR
A
A
A85184
A85183
Fig. 39—Sidewall Termination of 12 in. or Less
(Dimension "A" is Touching or 2-In.
Maximum Separation)
Fig. 40—Sidewall Termination of More Than 12 in.
(Dimension "A" is Touching or 2-In.
Maximum Separation)
28
Drain pipe and fittings must conform to ANSI standards and
ASTM D1785 or D2846. CPVC or PVC cement and primer must
conform to ASTM D2564 or F493. In Canada, use CSA or c-UL
certified schedule 40 CPVC or PVC drain pipe, fittings, and
cement.
When a condensate pump is required, select a pump which is
approved for condensing furnace applications. To avoid condensate spillage, select a pump with an overflow switch.
OPEN STAND
PIPE FOR
A/C OR
HUMIDIFIER
DRAIN
TEE
32°F MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED
TO OPEN
DRAIN
A94054
Fig. 41—Example of Field Drain Attachment
A93058
shielded, and waterproof heat tape. See Installation Instructions
supplied with accessory or heat tape manufacturer’s recommendations.
Unit must not be installed, operated, and then turned off and
left in an unoccupied structure during cold weather when
temperature drops to 32°F and below unless drain trap and
drain line have adequate freeze protection. See Service and
Maintenance Instructions for winterizing procedure.
1. Fold heat tape in half and wrap on itself 3 times.
2. Locate heat tape between sides of condensate trap back. (See
Fig. 42.)
3. Use wire ties to secure heat tape in place. Wire ties can be
positioned in notches of condensate trap sides. (See Fig. 42.)
4. Wrap field drain pipe with remaining heat tape, approximately
1 wrap per ft.
Step 2—Application
The furnace, A/C, and humidifier drains may be combined and
drained together. The A/C drain must have an external, fieldsupplied trap prior to the furnace drain connection. All drain
connections (furnace, A/C, or humidifier) must be terminated into
an open or vented drain as close to the respective equipment as
possible to prevent siphoning of the equipment’s drain.
5. When using field-supplied heat tape, follow heat tape manufacturer’s instructions for all other installation guidelines.
CONDENSATE TRAP
See Fig. 41 for example of possible field drain attachment using
1/2-in. CPVC or PVC tee for vent and A/C or humidifier drain
connection.
Outdoor draining of the furnace is permissible if allowed by local
codes. Caution should be taken when freezing ambient may freeze
drain pipe and prohibit draining.
WIRE TIE(S)
Caution should be taken to prevent draining where slippery
conditions may cause personal injuries. Excessive condensate
draining may cause saturated soil conditions which may result
in damage to plants.
HEAT TAPE
(3 WRAPS MINIMUM)
Step 3—Condensate Drain Protection
Freezing condensate left in condensate trap and drain line may
cause cracks, and possible water damage may occur. If freeze
protection is required, use condensate freeze protection accessory
or equivalent 3 to 6 watt per ft at 120v and 40°F self-regulating,
Fig. 42—Condensate Trap Heat Tape
29
A93036
SEQUENCE OF OPERATION
If a "call for heat" (R-W) occurs while thermostat is in continuous
blower mode, blower stops to allow furnace heat exchangers to
heat up more quickly, then restarts at end of blower on delay
period of 60 sec.
Furnace control must be grounded for proper operation, or
control will lockout. Control is grounded through green wire
routed to gas valve and burner box screw.
Blower reverts to continuous operation after heating cycle is
completed.
Using schematic diagram, follow sequence of operation through
different modes. (See Fig. 24.) This furnace has a new control
system. Read and follow wiring diagram carefully.
If a "call for cooling" (R-Y) occurs while thermostat is in
continuous blower mode, blower changes from continuous blower
speed (heating speed) to cooling speed.
NOTE: If 115-v power supply to furnace or 24-v blower access
panel switch is interrupted during a call for heat, blower operates
for 90 sec when power is restored before heating cycle is resumed.
When thermostat cooling call is satisfied, R-Y opens and blower
operates an additional 90 sec at cooling speed before reverting
back to continuous operation (heating speed).
Step 1—Heating Mode
Step 4—Heat Pump Mode
When wall thermostat "calls for heat," R-W circuit closes. Furnace
control performs a self-check, verifies pressure switch contacts are
open, and starts inducer motor.
When installed with a heat pump, furnace control automatically
changes blower on delay timing sequence to avoid no blower
operation time during demand defrost cycles. When R-W and R-Y
or R-W, R-Y, and R-G thermostat inputs are received at the same
time at furnace control center, control starts blower in heating
speed. Then a gas heat mode begins. Blower remains operating at
heating speed for 15 sec or until end of prepurge period, then
blower shuts off until end of ignitor warm up and trial for ignition
periods (a total of 24 sec). Blower restarts at heating speed.
1. Prepurge period—As inducer motor comes up to speed,
pressure switch contacts close to begin a 15-sec prepurge
period.
2. Ignitor warm up—At end of prepurge period, ignitor is
energized for a 17-sec ignitor warm-up period.
3. Ignition sequence—When ignitor warm-up period is completed, gas valve opens, permitting gas flow to burners where
it is ignited. After 5 sec, ignitor is de-energized and a 2-sec
flame-sensing period begins.
When R-W thermostat call disappears, control completes inducer
post-purge period (15 sec) and changes to cooling speed after a
2-sec delay.
If R-W, R-Y, and R-G thermostat signals should disappear
simultaneously, blower remains on for selected heating blower off
delay period (90, 135, 180, or 225 sec), and the inducer goes
through 15 sec post-purge period. If R-W and R-Y thermostat
signals should disappear, leaving R-G thermostat signal, blower
remains on in heating speed and inducer remains on for 15 sec to
complete post-purge period.
HUM terminal on control center is energized with gas valve.
See Accessories — Humidifier section.
4. Flame sensing—When burner flame is sensed, control begins
blower on delay period and continues holding gas valve open.
If burner flame is not sensed, control center de-energizes gas
valve and ignition sequence is repeated.
Control initiates a 90-sec blower only on period before starting
another heat pump cycle if there is a power interruption. Anytime
control senses false flame, control locks out of heating mode. This
reaction occurs because control ignores W input due to false flame
signal and, as a result, sees only Y input and goes into cooling
mode blower off delay. All other control functions remain in
standard format.
NOTE: Ignition sequence repeats 3 additional times before a
lockout occurs. Lockout automatically resets after 3 hr or can be
manually reset by turning off 115v (not at thermostat) for 3 sec
minimum, then turning it on again.
5. Blower on delay—Sixty sec after burner flame is proven,
blower motor is energized on heating speed. Simultaneously,
electronic air cleaner terminal EAC-1 is energized.
NOTE: EAC-1 terminal is energized whenever blower operates.
HUM terminal is only energized when gas valve is energized.
6. Blower off delay—When thermostat is satisfied, circuit between R-W is opened, de-energizing gas valve (stopping gas
flow to burners) and humidifier. Blower motor and electronic
air cleaner remains energized 90, 135, 180, or 225 sec
(depending on blower off time selection). Furnace is factory
shipped set for a 135-sec blower off delay.
Step 5—Component Test
NOTE: All components are functionally operated except the gas
valve.
Component Test can be initiated by one of the following procedures.
7. Post purge—Inducer motor remains energized 15 sec after
burners are extinguished.
REMOVING MAIN LIMIT SWITCH WIRE
Step 2—Cooling Mode
NOTE: NO thermostat signal may be present at control center
and all blower time delay off periods must be completed.
When thermostat "calls for cooling," R-G and R-Y circuits close.
R-Y circuit starts outdoor condensing unit, and combined R-Y and
R-G circuit starts furnace blower motor on cooling speed. Electronic air cleaner EAC-1 terminal is energized with 115v whenever
blower is operating.
1. Leave 115-v power to furnace turned on.
2. Remove main furnace door.
3. Look into blower access panel sight glass for current LED
status.
When thermostat is satisfied, R-G and R-Y circuits are opened,
furnace blower continues operating on cooling speed for an
additional 90 sec.
4. Remove blower access panel.
NOTE: Leave blower access panel installed to maintain power to
control center to view current LED status.
Step 3—Continuous Blower Mode
When R-G circuit is made, blower motor operates on heating
speed.
5. BRIEFLY remove either wire from the main limit switch until
the LED goes out, then reconnect it.
NOTE: Electronic air cleaner EAC-1 terminal is energized with
115v whenever blower is operating.
NOTE: If wire to main limit is disconnected longer than 4 sec,
main blower will start and retrieval request will be ignored.
30
6. When above items have been completed, the following will
occur:
a. LED flashes a fault code 4 times. Record this fault code for
further troubleshooting.
b. Inducer motor operates for 10 sec, then turns off,
c. Hot surface ignitor is energized for 15 sec, then deenergized.
d. Main blower operates at cooling speed for 10 sec, then
turns off.
e. Main blower operates at heating speed for 10 sec, then
turns off.
7. After component test is completed and LED is ON continuously indicating the furnace is ready to operate when a signal
from the thermostat is received, replace main furnace door.
JUMPERING CONTROL TEST TERMINAL
1. Remove main furnace door.
2. Remove blower access panel.
3. Manually close blower access panel door switch.
These furnaces are equipped with a manual reset limit switch
in burner box. This switch will open if an overheat condition
(rollout) occurs in burner enclosure. Correct inadequate
combustion-air supply or improper venting condition and
reset switch. DO NOT jumper this switch.
Before operating furnace, check each manual reset switch for
continuity. If necessary, press button to reset switch.
Step 2—Prime Condensate Trap with Water
Condensate trap must be PRIMED or proper draining may not
occur. The condensate trap has 2 internal chambers which can
ONLY be primed by pouring water into the inducer drain side
of condensate trap.
1. Remove upper inducer housing drain connection cap. (See
Fig. 43.)
2. Connect field-supplied 1/2-in. ID tube to upper inducer
housing drain connection.
Blower access panel door switch opens 24-v power to control
center. No component operation can occur. The 115-v power
is still present at control center and transformer. Caution must
be taken when manually closing this switch for service
purposes. Failure to follow this warning could result in
personal injury or death.
3. Insert field-supplied funnel into tube.
4. Pour 1 quart of water into funnel/tube. Water should run
through inducer housing, overfill condensate trap, and flow
into open field drain. (See Fig. 44.)
5. Remove funnel and tube from inducer housing and replace
drain connection cap and clamp.
4. BRIEFLY short (jumper) TEST, 1/4-in. quick-connect terminal on control center (adjacent to the LED diagnostic light)
and the Com terminal on thermostat connection block. (See
Fig 14.)
NOTE: If TEST to Com terminals are jumpered longer than 2 sec,
LED will flash rapidly, and retrieval request will be ignored.
5. Component Test will function as described above.
6. After component test is completed and furnace is operating
properly, remove device used to manually close blower access
panel door switch, replace blower access panel, and replace
main furnace door.
Step 3—Purge Gas Lines
If not previously done, purge lines after all connections have been
made and check for leaks.
Never purge a gas line into a combustion chamber. Never use
matches, candles, flame, or other sources of ignition for
purpose of checking leakage. Use a soap-and-water solution
to check for leakage. Failure to follow this warning could
result in fire, explosion, personal injury, or death.
START-UP PROCEDURES
Step 1—General
1. Furnace must have a 115-v power supply properly connected
and grounded. Proper polarity must be maintained for correct
operation.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control center fault indicator light will flash
rapidly and furnace will not operate.
2. Thermostat wire connections at terminals R, W, G, and Y
must be made at 24-v terminal block on control center.
3. Natural gas service pressure must not exceed 0.5 psig (14-in.
wc), but must be no less than 0.16 psig (4.5-in. wc).
4. Blower access door must be in place to complete 24-v
electrical circuit to furnace.
Step 4—Adjustments
SET GAS INPUT RATE
Measured gas input must be within ±2 percent of gas input on unit
rating plate. (0-2000 ft altitude.)
There are 2 methods of adjusting gas input rate. The preferred
method is by using Table 7 and following instructions in item 1.
The second method is by clocking gas meter as outlined in item 2.
Item 2 must be used for altitudes above 2000 ft.
1. Determine natural gas orifice size and manifold pressure for
correct input by using Table 7, then adjust manifold pressure
per item 3.
a. Obtain average yearly heat value for local gas supply.
b. Obtain average yearly specific gravity for local gas supply.
c. Verify furnace model. Table 7 can only be used for model
58MCA or 58MXA furnaces.
d. Find natural gas heat value and specific gravity in Table 7.
e. Follow heat value line and specific gravity line to point of
intersection to find orifice size and manifold pressure
settings for proper operation and given natural gas condition.
31
A94208
A94209
Fig. 43—Inducer Housing Drain Tube
Fig. 44—Filling Condensate Trap
EXAMPLE:
Heating value = 1010 Btu/cu ft
Specific gravity = 0.62
Therefore: Orifice No. 44*
Manifold pressure 3.3-in. wc
* Furnace is shipped with No. 45 orifices. In this example
all main burner orifices must be changed and manifold
pressure adjusted.
EXAMPLE:
Btu heating input = Btu/cu ft X cu ft/hr
Heating value of gas = 1010 Btu/cu ft
Time for 1 revolution of 2-cu ft dial = 72 sec
Gas rate = 100 cu ft/hr (from Table 8)
Btu heating input = 100 X 1010 = 101,000 Btuh
In this example, the orifice size and manifold pressure
adjustment is within ±2 percent of the furnace input rate.
Check and verify orifice size in furnace. NEVER ASSUME
ORIFICE SIZE; ALWAYS CHECK AND VERIFY.
NOTE: High altitude—Gas input on rating plate is for altitudes
up to 2000 ft. Ratings for altitudes over 2000 ft must be 4 percent
less for each 1000 ft above sea level. To obtain altitude adjusted
rating, adjust manifold pressure (see item 3) and replace main
burner orifices as needed. Refer to NFGC Appendix F, Table F-4
for proper orifice sizing at high altitudes.
NOTE: In Canada installation applications from 2000 to 4500 ft
above sea level are derated 10 percent from Conversion Station.
f. Proceed to item 3 to adjust manifold pressure.
3. Adjust gas input.
NOTE: Manifold pressure must always be measured with burner
enclosure front REMOVED. Gas meter must always be clocked
with burner enclosure front INSTALLED. Gas valve has been
nominally set at 3.5-in. wc for natural gas.
a. Remove burner enclosure front and cap that conceals
adjustment screw for gas valve regulator. (See Fig. 45.)
b. Turn adjusting screw either counterclockwise (out) to
decrease input rate or clockwise (in) to increase rate. When
adjusting input rate, DO NOT set manifold pressure less
Proceed to item 3 to adjust manifold pressure.
2. Determine natural gas input rate by clocking gas meter then
adjust manifold pressure per item 3.
NOTE: Be sure all pressure tubing, combustion-air and vent
pipes, and burner enclosure front are in place when checking input
by clocking gas meter.
a. Obtain average yearly heat value for local gas supply.
NOTE: Be sure heating value of gas used for calculations is
correct for your altitude. Consult local gas utility for altitude
adjustments of gas heating value. Turn off all other gas appliances
and pilots.
b. Start furnace and let run for 3 minutes.
c. Measure time (in sec) for gas meter test dial to complete 1
revolution.
d. Refer to Table 8 for cubic ft of gas per hr.
e. Multiply gas rate (cu ft/hr) X heating value (Btu/cu ft).
Obtain heating value from local gas utility.
32
Table 7—Model 58MCA or 58MXA Orifice Size and Manifold Pressure for Correct Input Rate
(Tabulated Data Based on Altitude Up to 2000 Ft and 20,000 Btuh Per Burner)
GAS HEAT
VALUE
(BTU/CU FT)
860
875
890
905
920
935
950
965
980
995
1010
1025
1040
1055
1070
1085
1100
Orf
No.
43
—
—
43
—
—
43
—
43
44
43
44
—
44
—
44
—
44
—
—
44
—
—
44
45
—
—
—
45
—
—
—
45
46
—
45
46
—
45
46
—
—
45
46
—
—
45
46
47
—
—
46
47
0.58
Mnfld
Press
3.7
—
—
3.7
—
—
3.5
—
3.3
3.8
3.2
3.7
—
3.6
—
3.5
—
3.4
—
—
3.3
—
—
3.2
3.8
—
—
—
3.7
—
—
—
3.6
3.8
—
3.5
3.7
—
3.4
3.6
—
—
3.3
3.5
—
—
3.2
3.4
3.8
—
—
3.3
3.7
Orf
No.
43
—
—
43
—
—
43
—
43
—
43
44
43
44
—
44
—
44
—
—
44
—
—
44
—
—
—
44
45
—
—
—
45
—
—
45
46
—
45
46
—
—
45
46
—
—
45
46
—
—
45
46
—
0.60
Mnfld
Press
3.8
—
—
3.8
—
—
3.6
—
3.5
—
3.3
3.8
3.2
3.7
—
3.6
—
3.5
—
—
3.4
—
—
3.3
—
—
—
3.2
3.8
—
—
—
3.7
—
—
3.6
3.8
—
3.5
3.7
—
—
3.4
3.6
—
—
3.3
3.5
—
—
3.2
3.4
—
Orf
No.
42
—
—
42
—
—
43
—
43
—
43
—
43
44
43
44
—
44
—
—
44
—
—
44
—
—
—
44
—
—
—
44
—
—
—
45
—
—
45
46
—
—
45
46
—
—
45
46
—
—
45
46
—
0.62
Mnfld
Press
3.2
—
—
3.2
—
—
3.7
—
3.6
—
3.5
—
3.3
3.8
3.2
3.7
—
3.6
—
—
3.5
—
—
3.4
—
—
—
3.3
—
—
—
3.2
—
—
—
3.7
—
—
3.6
3.8
—
—
3.5
3.7
—
—
3.4
3.6
—
—
3.4
3.5
—
Orf
No.
42
—
—
42
—
—
43
—
43
—
43
—
43
—
43
44
43
44
—
—
44
—
—
44
—
—
—
44
—
—
—
44
—
—
44
—
—
—
45
—
—
—
45
46
—
—
45
46
—
—
45
46
—
0.64
Mnfld
Press
3.3
—
—
3.3
—
—
3.8
—
3.7
—
3.6
—
3.5
—
3.3
3.8
3.2
3.7
—
—
3.6
—
—
3.5
—
—
—
3.4
—
—
—
3.4
—
—
3.2
—
—
—
3.8
—
—
—
3.7
3.8
—
—
3.6
3.7
—
—
3.5
3.6
—
than 3.2-in. wc or more than 3.8-in. wc for natural gas.
Make any major adjustments by changing main burner
orifices.
Orf
No.
42
—
—
42
—
—
42
—
43
—
43
—
43
—
43
—
43
44
—
43
44
—
—
44
—
—
—
44
—
—
—
44
—
—
44
—
—
44
—
—
—
—
45
—
—
—
45
—
—
—
45
46
—
0.66
Mnfld
Press
3.4
—
—
3.4
—
—
3.2
—
3.8
—
3.7
—
3.6
—
3.4
—
3.3
3.8
—
3.7
3.7
—
—
3.6
—
—
—
3.5
—
—
—
3.5
—
—
3.3
—
—
3.2
—
—
—
—
3.8
—
—
—
3.7
—
—
—
3.6
3.8
—
Orf
No.
—
41
42
—
41
42
42
—
—
42
43
—
43
—
43
—
43
—
—
43
44
—
43
44
—
—
—
44
—
—
—
44
—
—
44
—
—
44
—
—
—
44
—
—
—
—
45
—
—
—
45
—
—
0.68
Mnfld
Press
—
3.2
3.6
—
3.2
3.6
3.3
—
—
3.2
3.8
—
3.7
—
3.6
—
3.4
—
—
3.3
3.8
—
3.2
3.7
—
—
—
3.6
—
—
—
3.6
—
—
3.4
—
—
3.3
—
—
—
3.2
—
—
—
—
3.8
—
—
—
3.7
—
—
Orf
No.
—
41
42
—
41
42
42
—
—
42
—
42
43
—
43
—
43
—
—
43
—
—
43
44
—
—
43
44
—
—
43
44
—
—
44
—
—
44
—
—
—
44
—
—
—
44
—
—
—
—
45
—
—
0.70
Mnfld
Press
3.3
3.7
—
3.2
3.5
—
3.4
—
—
3.3
—
3.2
3.8
—
3.7
—
3.5
—
—
3.4
—
—
3.3
3.8
—
—
3.2
3.7
—
—
3.2
3.7
—
—
3.5
—
—
3.4
—
—
—
3.3
—
—
—
3.2
—
—
—
—
3.8
—
—
Orf
No.
41
42
—
41
42
—
41
42
—
42
—
42
—
42
43
—
43
—
—
43
—
—
43
—
—
—
43
44
—
—
43
44
—
—
44
—
—
44
—
—
—
44
—
—
—
44
—
—
—
44
—
—
—
0.72
Mnfld
Press
3.4
3.8
—
3.3
3.6
—
3.2
3.5
—
3.4
—
3.3
—
3.2
3.8
—
3.6
—
—
3.5
—
—
3.4
—
—
—
3.3
3.8
—
—
3.3
3.8
—
—
3.6
—
—
3.5
—
—
—
3.4
—
—
—
3.3
—
—
—
3.2
—
—
—
Be sure burner enclosure front is in place after adjustments
have been made.
NOTE: If orifice hole appears damaged or it is suspected to have
been redrilled, check orifice hole with a numbered drill bit of
correct size. Never redrill an orifice. A burr-free and squarely
aligned orifice hole is essential for proper flame characteristics.
e. Look through sight glass in burner enclosure and check
burner flame. Burner flame should be clear blue, almost
transparent. (See Fig. 46.)
c. Replace burner enclosure front and measure adjusted gas
input rate using method outlined in item 1 or 2.
d. Replace cap that conceals gas valve regulator adjustment
screw.
33
Table 8—Gas Rate (Cu Ft/Hr)
10
11
12
13
14
360
327
300
277
257
720
655
600
555
514
1800
1636
1500
1385
1286
50
51
52
53
54
72
71
69
68
67
144
141
138
136
133
360
355
346
340
333
15
16
17
18
19
240
225
212
200
189
480
450
424
400
379
1200
1125
1059
1000
947
55
56
57
58
59
65
64
63
62
61
131
129
126
124
122
327
321
316
310
305
20
21
22
23
24
180
171
164
157
150
360
343
327
313
300
900
857
818
783
750
60
62
64
66
68
60
58
56
54
53
120
116
112
109
106
300
290
281
273
265
25
26
27
28
29
144
138
133
129
124
288
277
267
257
248
720
692
667
643
621
70
72
74
76
78
51
50
48
47
46
103
100
97
95
92
257
250
243
237
231
30
31
32
33
34
120
116
113
109
106
240
232
225
218
212
600
581
563
545
529
80
82
84
86
88
45
44
43
42
41
90
88
86
84
82
225
220
214
209
205
35
36
37
38
39
103
100
97
95
92
206
200
195
189
185
514
500
486
474
462
90
92
94
96
98
40
39
38
38
37
80
78
76
75
74
200
196
192
188
184
40
41
42
43
44
90
88
86
84
82
180
176
172
167
164
450
439
429
419
409
100
102
104
106
108
36
35
35
34
33
72
71
69
68
67
180
178
173
170
167
45
46
47
48
49
80
78
76
75
73
160
157
153
150
147
400
391
383
375
367
110
112
116
120
33
32
31
30
65
64
62
60
164
161
155
150
REGULATOR
ADJUSTMENT
MANUAL
ON/OFF
SIZE OF TEST DIAL
SIZE OF TEST DIAL
SECONDS
SECONDS
FOR 1
FOR 1
1
2
5
1
2
5
REVOLUTION cu ft cu ft
cu ft REVOLUTION cu ft
cu ft
cu ft
INLET
PRESSURE
TAP
BURNER
ENCLOSURE
REFERENCE
PRESSURE
TAP
OF
F
MANIFOLD
PRESSURE TAP
A91062
Fig. 45—Redundant Automatic Gas Valve
BURNER FLAME
BURNER
MANIFOLD
A89020
Fig. 46—Burner Flame
SET TEMPERATURE RISE
Temperature rise must be within limits specified on unit
rating plate. Recommended operation is at midpoint of rise or
above. Failure to follow this caution may result in condensing
or overheating the heat exchangers.
A93059
Determine and adjust air temperature rise as follows:
1. Place thermometers in return and supply ducts as near furnace
as possible. Be sure thermometers do not see heat exchanger
so that radiant heat does not affect readings. This practice is
particularly important with straight-run ducts.
DO NOT redrill orifices. Improper drilling (burrs, out-ofround holes, etc.) can cause excessive burner noise and
misdirection of burner flames. This can result in flame
impingement of burners and heat exchangers causing failures.
2. When thermometer readings stabilize, subtract return-air temperature from supply-air temperature to determine air temperature rise.
3. Adjust temperature rise by adjusting blower speed. Increase
blower speed to reduce temperature rise. Decrease blower
speed to increase temperature rise.
34
THERMOSTAT SUBBASE
TERMINALS WITH
THERMOSTAT REMOVED
Disconnect 115-v electrical power before changing speed tap.
Failure to follow this warning could result in personal injury.
HOOK-AROUND
VOLT/AMMETER
4. To change blower motor speed selections for heating mode,
remove blower motor lead from control center HEAT terminal. (See Fig. 25.) Select desired blower motor speed lead
from 1 of the other terminals and relocate it to HEAT terminal.
See Table 9 for lead color identification. Reconnect original
lead on SPARE terminal.
R Y W G
Follow this same procedure for proper selection of COOL
speed selection.
Table 9–Speed Selector
10 TURNS
COLOR
SPEED
FACTORY ATTACHED TO
Black
High
Cool
Yellow (When Present) Medium High
Spare
Blue
Medium Low
Heat
Red
Low
Spare
White
Common
Com
FROM UNIT 24-VOLT
TERMINAL BLOCK
EXAMPLE: 5.0 AMPS ON AMMETER
10 TURNS AROUND JAWS
= 0.5 AMPS FOR THERMOSTAT SETTING
A80201
Fig. 47–Amp Draw Check with Ammeter
ADJUST BLOWER OFF DELAY (HEAT MODE)
If desired, the main blower time delay off period may be
lengthened or shortened when operating in the heating mode to
provide greater comfort. See Table 10 for position of switches and
Fig. 24 or 25 for location of switches on control center.
2. Remove main furnace door and disconnect inducer motor lead
wires from wire harness.
3. Turn on 115-v power to furnace.
4. Set thermostat to "call for heat" and wait 1 minute. When
pressure switch is functioning properly, hot surface ignitor
should NOT glow, and control center diagnostic light flashes
a 31 fault. If hot surface ignitor glows when inducer motor is
disconnected, shut furnace down immediately. Determine
reason pressure switch did not function properly and correct
condition.
Table 10—Blower Off Delay Setup Switch
Position
DESIRED HEATING
MODE BLOWER OFF
DELAY (SEC)
90
135
180
225
SETUP SWITCH POSITION
SW-1
SW-2
OFF
ON
OFF
ON
OFF
OFF
ON
ON
5. Turn off 115-v power to furnace.
6. Reconnect inducer motor leads, reinstall main furnace door,
and turn on 115-v power supply.
CHECKLIST
1. Put away tools and instruments. Clean up debris.
SET THERMOSTAT HEAT ANTICIPATOR
Thermostat heat anticipator must be set to match amp draw of
components in R-W circuit. Accurate amp draw measurements can
be obtained at thermostat subbase terminals R and W.
2. Verify manual reset switch has continuity.
3. Verify that blower and control access doors are properly
installed.
Fig. 47 illustrates an easy method of obtaining these measurements. Amp reading should be taken after blower motor has
started. See thermostat manufacturer’s instructions for adjusting
heat anticipator and for varying heating cycle length.
4. Cycle test furnace with room thermostat.
5. Check operation of accessories per manufacturer’s instructions.
6. Review User’s Guide with owner.
CHECK SAFETY CONTROLS
7. Leave literature packet near furnace.
Step 1—Check Primary Limit Control
This control shuts off combustion control system and energizes
air-circulating blower motor if furnace overheats. Recommended
method of checking this limit control is to gradually block off
return air after furnace has been operating for a period of at least
5 minutes. As soon as limit control has shut off burners, return-air
opening should be unblocked to permit normal air circulation. By
using this method to check limit control, it can be established that
limit is functioning properly and operates if there is a restricted
return-air supply or motor failure. If limit control does not function
during this test, cause must be determined and corrected.
Step 2—Check Pressure Switch
This control proves operation of draft inducer. Check switch
operation as follows:
1. Turn off 115-v power to furnace.
35
CHECKLIST—INSTALLATION
Condensate Drain
Load Calculation
____________
Heating Load (Btuh)
____________
Cooling Load (Btuh)
____________
Furnace Model Selection
________
Unit Level or Pitched Forward
________
Internal Tubing Connections Free of
Kinks and Traps
________
External Drain Connection Leak Tight
and Sloped
________
Condensate Trap Primed before
Start-Up
________
Heat Tape Installed if Required
COMBUSTION AND VENT PIPING
Termination Location
________
Roof or Sidewall
________
Termination Kit — 2 Pipe or Concentric
________
Combustion-Air Pipe Length
________
Gas Input Rate (Set Within 2 percent
of Rating Plate)
________
Combustion-Air Pipe Elbow Quantity
________
Temperature Rise Adjusted
________
Vent Pipe Length
________
Vent Pipe Length Quantity
________
Anticipator Setting Adjusted or
________
Pipe Diameter Determined from Sizing
Table
________
Cycle Rate (3 Cycles per Hr) Selected
________
Pipe Sloped To Furnace
Pipe Insulation
________
Over Ceilings
________
Low-Ambient Exposed Pipes
Copyright 1994 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231
CHECKLIST—START-UP
Thermostat Anticipator
Safety Controls Check Operation
________
Primary Limit
________
Pressure Switch
58mxa3si
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Catalog No. 565-830
Printed in U.S.A.
Form 58MXA-3SI
Pg 36
12-94
Replaces: 58MXA-2SI
Tab 6a 8a