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915SB: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
54
Table 22 – Orifice Size and Manifold Pressure (in. w.c.) for Gas
Input Rate
26,000 BTUH ONLY
A150571
(Continued) - Orifice Size and Manifold Pressure (in. w.c.)
for Gas Input Rate
26,000 BTUH ONLY
A150572
SERVICE AND MAINTENANCE PROCEDURES
Untrained personnel can perform basic maintenance functions such as
cleaning and replacing air filters. All other operations must be performed
by trained service personnel. A qualified service person should inspect
the furnace once a year.
General
These instructions are written as if the furnace is installed in an upflow
application. An upflow furnace application is where the blower is
located below the combustion and controls section of the furnace, and
conditioned air is discharged upward. Since this furnace can be installed
in any of the 4 positions shown in
, you must revise your
orientation to component location accordingly.
Electrical Controls and Wiring
Each pressure switch is labeled with the reference location (noted as
“COLLECTOR BOX-LPS” or “HOUSING-HPS” on the switch). The
nominal break point of each switch is shown on the label below the
reference location in inches of water column, “W.C.” The maximum and
minimum break point of the switch is +/- 0.05 inches of water column
from the nominal break point of the switch. The maximum make point of
the switch is 0.10 inches of water above the maximum break point of the
switch.
AVG. GAS
HEAT VALUE
AT ALTITUDE
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
(Btu/cu ft)
No.
Pressure
No.
Pressure
No.
Pressure
No.
Pressure
900
44
1.8
43
1.7
43
1.7
43
1.8
0
925
44
1.7
44
1.8
43
1.6
43
1.7
(0)
950
44
1.6
44
1.7
44
1.8
44
1.8
975
44
1.6
44
1.6
44
1.7
44
1.7
to
1000
44
1.5
44
1.5
44
1.6
44
1.6
1025
44
1.4
44
1.5
44
1.5
44
1.6
2000
1050
44
1.3
44
1.4
44
1.4
44
1.5
(610)
1075
44
1.3
44
1.3
44
1.4
44
1.4
1100
44
1.2
44
1.3
44
1.3
44
1.4
U.S.A.
800
43
1.7
43
1.8
43
1.8
42
1.6
2001 (611)
825
43
1.6
43
1.7
43
1.7
43
1.8
to
850
44
1.8
44
1.8
43
1.6
43
1.7
3000 (914)
875
44
1.7
44
1.7
44
1.8
44
1.8
900
44
1.6
44
1.6
44
1.7
44
1.7
Canada
925
44
1.5
44
1.5
44
1.6
44
1.6
2001 (611)
950
44
1.4
44
1.5
44
1.5
44
1.6
to
975
44
1.3
44
1.4
44
1.4
44
1.5
4500 (1372)
1000
44
1.3
44
1.3
44
1.4
44
1.4
775
43
1.7
43
1.8
43
1.8
42
1.5
800
44
1.8
43
1.7
43
1.7
43
1.8
3001
825
44
1.7
44
1.8
44
1.8
43
1.7
(915)
850
44
1.6
44
1.7
44
1.7
44
1.8
875
44
1.5
44
1.6
44
1.6
44
1.7
900
44
1.4
44
1.5
44
1.5
44
1.6
4000
925
44
1.4
44
1.4
44
1.5
44
1.5
(1219)
950
44
1.3
44
1.3
44
1.4
44
1.4
750
43
1.7
43
1.7
43
1.8
43
1.8
775
44
1.8
43
1.6
43
1.7
43
1.7
4001
800
44
1.7
44
1.7
44
1.8
43
1.6
(1220)
825
44
1.6
44
1.6
44
1.7
44
1.8
850
44
1.5
44
1.5
44
1.6
44
1.7
to
875
44
1.4
44
1.5
44
1.5
44
1.6
5000
900
44
1.3
44
1.4
44
1.4
44
1.5
(1524)
925
44
1.3
44
1.3
44
1.4
44
1.4
725
43
1.7
43
1.7
43
1.8
43
1.8
5001
750
44
1.8
44
1.8
43
1.7
43
1.7
(1525)
775
44
1.7
44
1.7
44
1.8
44
1.8
800
44
1.6
44
1.6
44
1.7
44
1.7
825
44
1.5
44
1.5
44
1.6
44
1.6
850
44
1.4
44
1.4
44
1.5
44
1.5
6000
875
44
1.3
44
1.3
44
1.4
44
1.4
(1829)
900
44
1.2
44
1.3
44
1.3
44
1.4
675
43
1.8
43
1.8
42
1.5
42
1.6
6001
700
43
1.6
43
1.7
43
1.7
43
1.8
(1830)
725
44
1.7
44
1.8
43
1.6
43
1.7
750
44
1.6
44
1.7
44
1.7
44
1.8
775
44
1.5
44
1.6
44
1.6
44
1.7
7000
800
44
1.4
44
1.5
44
1.5
44
1.6
(2133)
825
44
1.3
44
1.4
44
1.4
44
1.5
850
44
1.3
44
1.3
44
1.4
44
1.4
* Orifice numbers shown in
BOLD
are factory-installed.
U.S.A. Only
U.S.A. Only
to
U.S.A. Only
to
ORIFICE SIZE* AND MANIFOLD PRESSURE (IN WC) FOR GAS INPUT RATE
(TABULATED DATA BASED ON 13,000 BTUH PER BURNER, DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL
ALTITUDE
RANGE
U.S.A. and Canada
U.S.A. and Canada
U.S.A. Only
ft (m)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
to
650
43
1.7
43
1.8
42
1.5
42
1.6
7001
675
44
1.8
43
1.7
43
1.7
43
1.8
(2134)
700
44
1.7
44
1.8
44
1.8
43
1.7
725
44
1.6
44
1.7
44
1.7
44
1.8
750
44
1.5
44
1.5
44
1.6
44
1.6
8000
775
44
1.4
44
1.4
44
1.5
44
1.5
(2438)
800
44
1.3
44
1.4
44
1.4
44
1.4
825
44
1.2
44
1.3
44
1.3
44
1.4
625
43
1.7
43
1.8
43
1.8
42
1.6
8001
650
44
1.8
43
1.7
43
1.7
43
1.8
(2439)
675
44
1.7
44
1.8
44
1.8
43
1.6
700
44
1.6
44
1.6
44
1.7
44
1.7
725
44
1.5
44
1.5
44
1.6
44
1.6
9000
750
44
1.4
44
1.4
44
1.5
44
1.5
(2743)
775
44
1.3
44
1.3
44
1.4
44
1.4
9001
600
43
1.7
43
1.8
43
1.8
42
1.6
(2744)
625
44
1.8
43
1.6
43
1.7
43
1.7
650
44
1.7
44
1.7
44
1.8
44
1.8
675
44
1.6
44
1.6
44
1.7
44
1.7
10000
700
44
1.4
44
1.5
44
1.5
44
1.6
(3048)
725
44
1.3
44
1.4
44
1.4
44
1.5
* Orifice numbers shown in
BOLD
are factory-installed.
U.S.A. Only
to
U.S.A. Only
to
U.S.A. Only
to
ORIFICE SIZE* AND MANIFOLD PRESSURE (IN WC) FOR GAS INPUT RATE
(TABULATED DATA BASED ON 13,000 BTUH PER BURNER, DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL
WARNING
!
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in personal injury, death
and/or property damage.
The ability to properly perform maintenance on this equipment requires
certain knowledge, mechanical skills, tools, and equipment. If you do
not possess these, do not attempt to perform any service and
maintenance on this equipment other than those procedures
recommended in the Owner’s Manual.
CAUTION
!
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental pollution.
Remove and recycle all components or materials (i.e. oil, refrigerant,
control board, etc.) before unit final disposal.
WARNING
!
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury or death,
or property damage.
Before installing, modifying, or servicing system, main electrical
disconnect switch must be in the OFF position and install a lockout tag.
There may be more than one disconnect switch. Lock out and tag
switch with a suitable warning label. Verify proper operation after
servicing. Always reinstall access doors after completing service and
maintenance.
CAUTION
!
ELECTRICAL OPERATION HAZARD
Failure to follow this caution may result in improper furnace operation
or failure of furnace.
Label all wires prior to disconnection when servicing controls. Wiring
errors can cause improper and dangerous operation.