Reznor SSCBL Installation and operating instructions

Revision: SSCBL-RPBL-IOM (10-22) 149159-C
INDOOR SEPARATED-COMBUSTION MODEL SSCBL
OUTDOOR POWER-VENTED MODEL RPBL
INDOOR AND OUTDOOR PACKAGED SYSTEM INSTALLATION,
OPERATION, AND MAINTENANCE
Supersedes: SSCBL-RPBL-IOM (08-22) 149159-B
⚠ DANGER ⚠
FIRE OR EXPLOSION HAZARD
• Failure to follow safety warnings exactly could result in serious injury, death, or property
damage.
• Improper installation,adjustment,alteration, service,or maintenance can cause serious injury,
death, or property damage.
• Installation and service must be performed by a qualified installer, service agency, or the gas
supplier.
• Be sure to read and understand the installation, operation, and service instructions in this
manual.
• Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or
any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Leave the building immediately.
• Immediately call your gas supplier from a phone remote from the building. Follow the gas
supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.
SSCBL
RPBL

2SSCBL-RPBL-IOM (10-22) 149159-C
TABLE OF CONTENTS
GENERAL INFORMATION .............................................................................4
References ........................................................................................4
Important Safety Information........................................................................... 4
Warranty ..........................................................................................5
Installation Codes ...................................................................................5
Dimensions ........................................................................................6
Weights........................................................................................... 7
Clearances ........................................................................................8
Package Configurations ..............................................................................8
Location ..........................................................................................8
Hazards of Chlorine ................................................................................. 8
INSTALLATION ......................................................................................9
Uncrating/Unpacking................................................................................. 9
Shipped-Separate Parts .............................................................................. 9
Mounting Support Structure ...........................................................................9
Curb Cap Base .................................................................................10
Optional Curb (Option CJ1, CJ2, CJ4, or CJ5) Assembly (Model RPBL) .....................................10
Field-Supplied Support Assembly ................................................................... 13
Mounting .........................................................................................14
Suspension (Model SSCBL) .......................................................................14
Mounting (Model SSCBL) .........................................................................15
Mounting (Model RPBL) .......................................................................... 15
Field-Installation of Cooling Coil Cabinet and Downturn Plenum .............................................. 16
Duct Connections ..................................................................................22
Requirements and Suggestions for Connecting and Installing Ducts ........................................ 23
Bottom Duct Connections (Model RPBL) ............................................................. 24
100% Outside Air Hood (Model RPBL with Option AS2).................................................. 25
Screened Air Hood for 30% Outside Air Opening (Model RPBL with Option AR6 or AR7)........................ 25
Evaporative Cooling Module (Option AS3, AS4, AS5, or AS8) .............................................25
Discharge Air Temperature Sensor Installation.........................................................25
Venting/Combustion Air Connections (Model SSCBL) ......................................................27
Specific Venting Requirements: Piping ............................................................... 27
Specific Venting Requirements: Venter Outlet and Combustion Air Inlet Connections...........................28
Specific Venting Requirements: Joints and Sealing .....................................................28
Specific Venting Requirements: Support.............................................................. 29
Specific Venting Requirements: Clearance ............................................................ 30
Specific Venting Requirements: Concentric Adapter Box ................................................. 30
Specific Venting Requirements: Concentric Adapter Box Pipe Connections ..................................31
Vent Terminal Options............................................................................ 32
Vertical Vent Terminal (Option CC2) Installation........................................................32
Horizontal Vent Terminal (Option CC6) Installation...................................................... 37
Venting Connections (Model RPBL) ....................................................................41
Piping Connections................................................................................. 42
Gas Supply Pressure............................................................................. 42
Gas Supply Piping............................................................................... 43
Supply Piping Connections ........................................................................ 43
Electrical Connections ..............................................................................45
Control Wiring ..................................................................................46
CONTROLS ........................................................................................49
Thermostat .......................................................................................49
Remote Console ...................................................................................49
Combustion Air Proving Switch........................................................................ 49
Blower Fan Control .................................................................................49
High Temperature Limit Control .......................................................................50

3
SSCBL-RPBL-IOM (10-22) 149159-C
TABLE OF CONTENTS—CONTINUED
Reverse Flow Limit Control (Model RPBL) ...............................................................50
High Ambient Limit Control (Model RPBL) ............................................................... 50
Airflow Proving Switch (Makeup Air with Option BW1) ...................................................... 50
Variable Frequency Drive ............................................................................ 50
Combination Gas Valve ............................................................................. 50
Optional Two-Stage Control (Heating Only Application).....................................................50
Optional Two-Stage Control (Makeup Air Application) ...................................................... 51
Optional Ductstat with Capillary Tubing (Option AG3, AG4, or AG5) ........................................ 51
Optional Ductstat with Remote Temperature Selector (Option AG15 , AG17, or AG19) ......................... 52
Optional Electronic Modulation ........................................................................52
Electronic Modulation Between 50% and 100% Firing Rate (Option AG7, AG8, or AG9) ........................ 52
Computer-Controlled Electronic Modulation Between 50% and 100% Firing Rate (Option AG21).................. 53
Electronic Modulation Between 25% and 100% Firing Rate (Options AG39, AG40, AG41, and AG42).............. 53
Computer-Controlled Electronic Modulation Between 25% and 100% Firing Rate (Options AG40 and AG42) ........ 54
Pilot and Ignition Systems............................................................................56
Burners and Carryover System........................................................................ 56
Dampers and Damper Controls ....................................................................... 57
Pressure Null Switch................................................................................ 57
Dirty Filter Switch ..................................................................................57
OPERATION ....................................................................................... 57
Pre-Startup Checklist ...............................................................................58
Startup ..........................................................................................58
Post-Startup Checklist ..............................................................................59
ADJUSTMENTS..................................................................................... 59
Belts, Blowers, and Drives ...........................................................................59
Checking and Adjusting Belt Tension ................................................................59
Adjusting Blower Speed ..........................................................................60
Reversing Blower Rotation ........................................................................61
Motor Load and Amp Adjustment ...................................................................... 61
Adjust Heat Stage Controllers (Option AG41 or AG42) .....................................................62
Pressure Null Switch Adjustment ......................................................................63
Measure and Adjust Manifold (Outlet) Gas Pressure ....................................................... 63
High Elevation (>2,000 Feet/609 Meters) Installations ................................................... 64
Conversion to LP (Propane) .......................................................................65
Dirty Filter Switch Adjustment ......................................................................... 65
Burner Air Shutter Adjustment ........................................................................ 66
Damper Linkage Adjustment.......................................................................... 67
MAINTENANCE..................................................................................... 67
Maintenance Procedures ............................................................................68
Combination Gas Valve Maintenance ................................................................68
Burner Rack Maintenance......................................................................... 69
Cleaning Pilot and Burners ........................................................................70
Spark Ignition System Maintenance .................................................................71
Blower Bearing Lubrication ........................................................................ 72
Venter Motor Maintenance ........................................................................ 72
Cooling Coil Maintenance ......................................................................... 72
Heat Exchanger Cleaning ......................................................................... 72
TROUBLESHOOTING ................................................................................ 73
APPENDIX: FILTER PRESSURE DROPS ................................................................ 75
INSTALLATION RECORD (TO BE COMPLETED BY INSTALLER)............................................. 76

4SSCBL-RPBL-IOM (10-22) 149159-C
Table 1. Related Technical Manuals Available from Factory Distributor
Type Form*PN
Replacement parts SC-SCE-SSCBL-SSCDBL 269822
RP-HRPD-RPB-RPBL 263984
Control system guide OPT-D19-D21-D22-D23 1042481
Maxitrol amplifier replacement kit installation OPT-AG7,8,9,9H 262319
Outside air hood installation RPB-RPBL-AS2 132901
30% screened air hood installation OPT-AIR-HOOD 131794
Evaporative cooling module installation OPT-AS3,4,5,8 160202
Ignition controller replacement kit installation OPT-IGN-CNTRL 134704
Gas conversion OPT-GC 143147
*Also available at www.reznorhvac.com.
GENERAL INFORMATION
•This unit has been tested for capacity and efficiency so as to provide many years of safe and dependable comfort
providing it is properly installed and maintained. With regular maintenance, this unit will operate satisfactorily year
after year. Abuse, improper use, and/or improper maintenance can shorten the life of the appliance and create
unsafe hazards.
•To achieve optimum performance and minimize equipment failure, it is recommended that periodic maintenance
be performed on this unit. The ability to properly perform maintenance on this equipment requires certain tools
and mechanical skills.
•These packaged systems include duct furnaces that are design-certified to ANSI and CSA standards by the
Canadian Standards Association and that are approved for installation in the United States and in Canada. The
furnaces are approved for use with either natural gas or propane. The type of gas for which the furnace is equipped,
the correct firing rate, and electrical requirements are shown on the unit’s rating plate.
References
Important Safety Information
Please read all information in this manual thoroughly and become familiar with the capabilities and use of your
appliance before attempting to operate or maintain this unit. Pay attention to all dangers, warnings, cautions, and
notes highlighted in this manual. Safety markings should not be ignored and are used frequently throughout to
designate a degree or level of seriousness.
DANGER: A danger statement describes a potentially hazardous situation that if not avoided, will result in severe
personal injury or death and/or property damage.
WARNING: A warning statement describes a potentially hazardous situation that if not avoided, can result in severe
personal injury and/or property damage.
CAUTION: A caution statement describes a potentially hazardous situation that if not avoided, can result in minor
or moderate personal injury and/or property damage.
NOTE: A note provides important information that should not be ignored.
⚠ DANGER ⚠
• Gas-fired appliances are not designed for use in hazardous atmospheres containing flammable
vapors or combustible dust,in atmospheres containing chlorinated or halogenated hydrocarbons,
or in applications with airborne silicone substances.
• Improper installation,adjustment,alteration,service,or maintenance can cause property damage,
injury, or death. Read these installation, operation, and maintenance instructions thoroughly
before installing or servicing this equipment.

5
SSCBL-RPBL-IOM (10-22) 149159-C
⚠ WARNING ⚠
For your safety, read the warning labels on the unit.
NOTES:
• Installation should be done by a qualified agency in accordance with the instructions in this
manual and in compliance with all codes and requirements of authorities having jurisdiction.
• Read this manual and become familiar with the installation requirements of your particular
furnace. If you do not have knowledge of local requirements, check with the local gas company
or any other local agencies who might have requirements concerning this installation.
• The instructions in this manual apply only to model SSCBL and RPBL units.
Warranty
Refer to the limited warranty information on the warranty card in the owner’s envelope. Warranty is void if:
a. Furnaces are used in atmospheres containing flammable vapors or atmospheres containing chlorinated or
halogenated hydrocarbons or any contaminant (silicone, aluminum oxide, etc.) that adheres to the spark
ignition flame sensing probe.
b. Wiring is not in accordance with the diagram furnished with the heater.
c. Unit is installed without proper clearance to combustible materials or without proper ventilation and air for
combustion.
d. Furnace air throughput is not adjusted within the range specified on the rating plate.
Installation Codes
•These units must be installed in accordance with local building codes. In the absence of local codes, in the United
States, the unit must be installed in accordance with NFPA/ANSI Z223.1 (latest edition), National Fuel Gas Code.
A Canadian installation must be in accordance with CSA B149.1, Natural Gas and Propane Installation Code. This
code is available from CSA Information Services, 1-800-463-6727. Local authorities having jurisdiction should be
consulted before installation is made to verify local codes and installation procedure requirements.
•These gas-fired products are certified by ANSI Z83 family of standards governing the safe usage of heating
equipment in the industrial/commercial marketplace. This includes using the heaters in makeup air applications to
supply corridor pressurization in commercial buildings such as office structures and apartment complexes.
•The heaters are not certified as residential heating equipment and should not be used as such.
• Clearances (model SSCBL): Clearances from the heater and vent to combustible construction or material in
storage must conform with the National Fuel Gas Code ANSI Z223.1 (latest edition) pertaining to gas-burning
devices, and such material must not attain a temperature over 160°F (71°C) by continued operation of the heater.
• Separated-combustion (model SSCBL): The separated-combustion furnaces in model SSCBL are designed and
manufactured in accordance with the ANSI definition of separated combustion, which reads, “Separated Combustion
System Appliance: A system consisting of an appliance and a vent cap(s) supplied by the manufacturer, and (1)
combustion air connections between the appliance and the outside atmosphere, and (2) flue gas connections between
the appliance and vent cap, of a type(s) specified by the manufacturer but supplied by the installer, constructed
so that, when installed in accordance with the manufacturer’s instructions, air for combustion is obtained from the
outside atmosphere and flue gases are discharged to the outside atmosphere.” Separated-combustion units are
designed to separate air for combustion and flue products from the environment of the building in which the unit
is installed. Separated-combustion appliances are recommended for use in dust-laden and some corrosive-fume
environments. As the definition states, all separated-combustion, power-vented equipment must be equipped with
both combustion-air and exhaust piping to the outdoors.
• Special installations in aircraft hangars and garages (model SSCBL): Installations in aircraft hangars should be
in accordance with NFPA No. 409 (latest edition), Standard for Aircraft Hangars; in public garages in accordance
with NFPA No. 88A (latest edition), Standard for Parking Structures; and for repair garages in accordance with
NFPA No. 88B (latest edition), Standard for Repair Garages. In Canada, installations in aircraft hangars, repair
garages, and parking garages should be in accordance with the requirements of the enforcing authorities and in
accordance with the CSA B149 code.

6SSCBL-RPBL-IOM (10-22) 149159-C
GENERAL INFORMATION—CONTINUED
Dimensions
Figure 1. SSCBL Dimensions (Refer to Table 2)
Table 2. SSCBL Dimensions
Dimension
(See Figure 1)
Unit Size
400 500, 600 700 800 1050 1200
Inches (mm)
A 58-7/8 (1495) 47-7/8 (1216) 53-3/8 (1356) 58-7/8 (1495) 53-3/8 (1356) 58-7/8 (1495)
B 47-5/8 (1210) 36-5/8 (930) 42-1/8 (1070) 47-5/8 (1210) 42-1/8 (1070) 47-5/8 (1210)
C 56-1/8 (1426) 45-1/8 (1146) 50-5/8 (1286) 56-1/8 (1426) 50-5/8 (1286) 56-1/8 (1426)
D 45-1/2 (1156) 34-1/2 (876) 40 (1016) 45-1/2 (1156) 40 (1016) 45-1/2 (1156)
E 83-1/2 (2121) 109-1/2 (2781) 135-1/2 (3442)
Air Opening (See Figure 1) Inches (mm)
Horizontal air inlet opening 19-1/2 (495) × B
Optional return air opening (bottom)
Horizontal discharge air opening 18 (457) D
Gas Connection Location*
(See Figure 1)
Approximate Distance from Inside Curb Cap
on Blower End of System Unit Size
1 89–90 pouces (2261–2286 mm) 400
2 103–104 pouces (2616–2642 mm) 500, 600, 700, 800
3 110–111 pouces (2794–2819 mm) 1050, 1200
*The gas connection is at curb cap height on the control side of the system.
FRONT VIEW
3/4
(19)
3/4
(19)
3/4
(19)
3/4
(19)
4-1/4
(108)
4-1/4
(108)
8-15/32
(215)
D
B
C
18 (457)
A
4-3/32
(104)
5 (127)
19-1/2
(495)
19-1/2
(495)
LEFT SIDE VIEW
7-13/32
(188)
7-13/32
(188)
7-13/32
(188)
11-11/32 (288)
18-1/2
(470)
18-1/2
(470)
40-1/8 (1019)
VENT
INLET AIR
FURNACE
CONTROL CONN
ELECTRIC
CONN GAS CONNS
E
(1) (2) (3)
VENTVENT
INLET AIRINLET AIR
FURNACEFURNACE
AIRFLOW
BLOWER
CABINET
OPTIONAL
RETURN
AIR
OPENING
NOTES:
Inches (mm)
The vent pipe collar OD = 6 (152). The inlet air
collar ID = 6 (152).
⚠ CAUTION ⚠
To ensure complete weather resistance, an outside air hood or evaporative cooling module is
required for model RPBL units.

7
SSCBL-RPBL-IOM (10-22) 149159-C
Figure 2. RPBL Dimensions (Refer to Table 3)
Table 3. RPBL Dimensions
Dimension
(See Figure 2)
Unit Size
400 500, 600 700 800 1050 1200
Inches (mm)
A 58-7/8 (1495) 47-1/8 (1216) 53-3/8 (1356) 58-7/8 (1495) 53-3/8 (1356) 58-7/8 (1495)
B 47-5/8 (1210) 36-5/8 (930) 42-1/8 (1070) 47-5/8 (1210) 42-1/8 (1070) 47-5/8 (1210)
C 56-1/8 (1426) 45-1/8 (1146) 50-5/8 (1286) 56-1/8 (1426) 50-5/8 (1286) 56-1/8 (1426)
D 45-1/2 (1156) 34-1/2 (876) 40 (1016) 45-1/2 (1156) 40 (1016) 45-1/2 (1156)
E83-3/4 (2127) 109-3/4 (2788) 135-3/4 (3448)
107-3/4 (2737)*133-3/4 (3397)*159-3/4 (4058)*
F60-5/16 (1532)*86-5/16 (2192)*112-5/16 (2853)*
Air Opening (See Figure 2) Inches (mm)
Standard horizontal air inlet opening
19-1/2 (495) × BOptional return air opening (bottom)
Optional discharge air opening with downturn plenum
Standard horizontal discharge air opening 18 (457) × D
Gas Connection Location**
(See Figure 2)
Approximate Distance from Inside Curb Cap
on Blower End of System Unit Size
1 89–90 inches (2261–2286 mm) 400
2 103–104 inches (2616–2642 mm) 500, 600, 700, 800
3 110–111 inches (2794–2819 mm) 1050, 1200
*With downturn plenum (option AQ5 or AQ8).
**The gas connection is at curb cap height on the control side of the system.
Weights
Table 4. Weights
Unit Size
400 500, 600 700 800 1050 1200
Net Weight (Pounds (kg))
849 (385) 1104 (500) 1184 (537) 1245 (565) 1476 (670) 1565 (710)
FRONT VIEW
(STANDARD HORIZONTAL DISCHARGE)
LEFT SIDE VIEW
CONTROL CONN
ELECTRIC CONN GAS CONNS
FURNACE
AIRFLOW
BLOWER
CABINET
CURB
CAP
OPTIONAL
RETURN AIR
OPENING
OPTIONAL
SUPPLY AIR
OPENING
4-3/32
(104) 19-1/2
(495)
19-1/2
(495)
3/4
(19)
3/4
(19)
3/4
(19)
3/4
(19)
4-1/4
(108)
4-1/4
(108)
4-3/32
(104)
8-15/32
(215)
40-1/8 (1019)
F
E
D
B
C
OPTIONAL
DOWNTURN
PLENUM
(2) (3)(1)
18 (457)
A
FURNACEFURNACE
AIRFLOWAIRFLOW
NOTES:
Inches (mm)
Burner and control access shown left-hand side. Specify right-hand side for opposite access and connections.

8SSCBL-RPBL-IOM (10-22) 149159-C
Package Configurations
Table 6. Package Configurations
Unit Size No. of Furnace Sections No. of Blower Cabinets
400 1
1500, 600, 700, 800 2
1050, 1200 3
GENERAL INFORMATION—CONTINUED
Clearances
Clearance to combustibles is defined as the minimum distance—from the heater to a surface or object—that is
necessary to ensure that a surface temperature of 90°F (50°C) above the surrounding ambient temperature is not
exceeded. For safety, adequate combustion air, and convenient installation and service, ensure that the clearances
listed in Table 5 are provided.
Location
⚠ CAUTION ⚠
Do not locate an indoor model SSCBL unit where it may be exposed to water spray, rain, or dripping
water.
•Select a location that complies with the requirements in this manual.
•There are a variety of factors, such as system application, building structure, dimensions, and weight, that contribute
to selecting the location.
•The location must comply with the clearances listed in Table 5.
•If the unit is equipped with an outside air hood, it is recommended that the inlet to the hood not be facing into the
prevailing wind.
Hazards of Chlorine
NOTE: Remember, chlorine is heavier than air.This fact should be kept in mind when determining
the installation location of heaters and building exhaust systems.
The presence of chlorine vapors in the combustion air of heating equipment presents a potential corrosion hazard.
Chlorine, found usually in the form of Freon or degreaser vapors, when exposed to flame will precipitate from the
compound and form a solution with any condensation present in the heat exchanger or associated parts. The result
is hydrochloric acid, which readily attacks all metals, including 300 grade stainless steel. Care should be taken to
separate these vapors from the combustion process. This may be done by wise location of the unit with regard to
exhausters or prevailing wind directions.
Table 5. Clearances
Unit Surface Model SSCBL Model RPBL
Minimum Clearance (Inches (mm))
Top 6 (152) —
Control side 56 (1422)
Side opposite controls, to combustibles 6 (152) —
Side opposite controls, for motor access 30 (762)
Bottom 6 (152) 0 (0)*
*When the unit is installed on a roof curb on a combustible roof, the roof area enclosed within the curb must be either ventilated, left open, or
covered with noncombustible material that has an R-value of at least 5.0.

9
SSCBL-RPBL-IOM (10-22) 149159-C
INSTALLATION
NOTE: Before installation,make preparations for necessary supplies,tools,and manpower.
Uncrating/Unpacking
•This furnace was test-operated and inspected at the factory prior to crating and was in operating condition. If
the furnace has incurred any damage in shipment, document the damage with the transporting agency and
immediately contact an authorized Reznor®distributor. If you are an authorized Distributor, follow the FOB freight
policy procedures.
•Check the rating plate for the gas specifications and electrical characteristics of the furnace to ensure that they
are compatible with the gas and electric supplies at the installation site.
Shipped-Separate Parts
•Check to see if there are any field-installed options that need to be connected to the furnace prior to installation.
• Model SSCBL: All model SSCBL installations require a vent/combustion air kit (option CC2 or CC6), which includes
a concentric adapter box, for each duct furnace. Ensure that all of the factory-supplied and field-supplied parts
needed for the vent/combustion air kit(s) are at the job site.
•Shipped-separate options could include a roof curb, a screened outside air hood, a gas shutoff valve, a thermostat,
a different control switch, a remote console, a manual fan switch, a vertical vent terminal, a vent extension, a gas
supply regulator, and/or a disconnect switch.
•If ordered with either an evaporative cooling module or a DX or chilled water cooling coil module, the module is
shipped separately. A drain and fill or freeze kit and a water hammer arrestor are shipped-separate options for an
evaporative cooling module.
•Some gas control options will have parts either shipped loose with the heater or shipped separately. If the unit is
equipped with any of the gas control options listed in Table 7, ensure that these parts are available at the job site.
Table 7. Shipped-Separate Parts for Gas Control Options
Application Option Part(s)
Heating
AG7 Thermostat (PN 48033)
AG10 Thermostat (PN 91919)
AG11 Thermostat (PN 93435)
Makeup air
AG3, AG8 Control switch (PN 29054)
AG9 Control switch (PN 29054), remote temperature selector (PN 48042)
AG15, AG17,
AG19 Control switch (PN 29054), remote temperature selector (PN 115848), stage adder module(s) (PN 115849)
AG39, AG41 Remote temperature selector (PN 174849)
NOTE: If an optional remote console is ordered, the control switch and temperature selector may be mounted on the console.
Mounting Support Structure
⚠ WARNING ⚠
Before installation, check the supporting structure to ensure that it has sufficient load-carrying
capacity to support the weight of the unit.
⚠ CAUTION ⚠
• Before installing the curb, verify that the size is correct for the system being installed.
• Whether using an optional roof curb available with the system or a field-supplied curb, the curb
must be secure, square and level.
• IMPORTANT:The area enclosed by the roof curb must comply withTable 5.If the roof is constructed
of combustible materials, the area within curb must be either ventilated, left open, or covered
with non-combustible material that has an R-value of at least 5.0.

10 SSCBL-RPBL-IOM (10-22) 149159-C
INSTALLATION—CONTINUED
Mounting Support Structure—Continued
NOTES:
• Prior to installation, ensure that the method of support is in agreement with all local building
codes and, for outdoor installations, is suited to the climate.
• If the area within the curb is left open, higher radiated sound levels may result.
• The system can have a variety of configurations that affect installation. If the system does not
have a downturn plenum, the discharge is horizontal.
Curb Cap Base
•Units are equipped with a load bearing curb cap that forms an integral part of the unit. The curb cap is welded at
all joints.
• Model SSCBL: The curb cap has suspension holes at each corner and hanger brackets on the sides. Each
suspension location requires a 1/2-inch threaded rod (refer to Suspension (Model SSCBL) section).
• Model RPBL: The curb cap has a skirt that fits over a roof curb to provide a weatherproof installation. Four holes
are provided at the curb cap corners for lifting the unit. These holes do not interfere with unit weatherproofing. The
curb cap is not designed to be placed directly on the roof surface. The system may be mounted on an optional roof
curb purchased with the unit, a field-supplied roof curb, or field-supplied supports. If the system has a downturn
plenum and/or a bottom return air opening, a roof curb is recommended to provide a weatherproof installation
as well as more workable clearances for ductwork (refer to Bottom Duct Connections (Model RPBL) section).
Optional Curb (Option CJ1, CJ2, CJ4, or CJ5) Assembly (Model RPBL)
NOTES:
• Curbs are shipped unassembled. Field-assembly and mounting on the roof are the responsibility
of the installer. All required hardware necessary to complete the assembly is provided.
• The system can have a variety of configurations that affect installation. Option CJ1 is for a
standard RPBL unit. Option CJ2 is for a unit with a factory-installed downturn plenum (option
AQ5 or AQ8). Option CJ4 is for a unit with a field-installed cooling coil cabinet (option AU2 or
AU3). Option CJ5 is for a unit with a field-installed cooling coil cabinet with a downturn plenum
(option AU11, AU12, AU13, or AU14). Figure 3 shows a unit with an option AQ5 or AQ8 downturn
plenum. If the system does not have a downturn plenum, the discharge is horizontal.
• Field installed means that the cooling coil cabinet, with or without the downturn, is factory-
assembled and shipped separately. The roof curb is sized to accommodate the complete length
of the system. The shipped-separate cooling coil cabinet, with or without a downturn, must be
lifted to the roof separately from the packaged system, set on the roof curb, and connected to
the furnace section.