441 01 2613 05
29
Specifications are subject to change without notice
MANIFOLD PRESSURE AND ORIFICE SIZE FOR HIGH ALTITUDE APPLICATIONS
Table 6
NATURAL GAS MANIFOLD PRESSURE (in wc)
HEATING
VALUE
at ALTITUDE
BTU/CU. FT.
MEAN ELEVATION ABOVE SEA LEVEL
!
ft(m)
0 to 2000
(0 to 610)
2001 to 3000
*
(610 to 914)
*
3001 to 4000
(915 to 1219)
4001 to 5000
(1220 to 1524)
5001 to 6000
(1524 to 1829)
6001 to 7000
(1829 to 2134
)
7001 to 8000
(2134 to 2438)
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
700
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
41
3.7
725
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
41
3.7
41
3.4
750
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
41
3.5
42
3.6
775
!!
!!
!!
!!
!!
!!
!!
!!
41
3.6
42
3.6
42
3.3
800
!!
!!
!!
!!
!!
!!
41
3.6
42
3.7
42
3.4
42
3.1
825
!!
!!
!!
!!
41
3.7
41
3.4
42
3.5
42
3.2
42
2.9
850
!!
!!
!!
!!
41
3.5
42
3.6
42
3.3
42
3.0
42
2.8
875
!!
!!
41
3.6
42
3.6
42
3.4
42
3.1
42
2.8
42
2.6
900
!!
!!
42
3.7
42
3.4
42
3.2
42
2.9
42
2.7
42
2.5
925
41
3.7
42
3.5
42
3.3
42
3.0
42
2.8
42
2.5
44
3.3
950
41
3.5
42
3.3
42
3.1
42
2.9
42
2.6
42
2.4
44
3.1
975
42
3.7
42
3.2
42
2.9
42
2.7
42
2.5
44
3.2
45
3.6
1000
42
3.5
42
3.0
42
2.8
42
2.6
42
2.4
45
3.7
45
3.4
1050
42
3.2
42
2.7
42
2.5
44
3.3
45
3.6
!!
!!
!!
!!
1100
43
3.6
42
2.5
44
3.2
45
3.6
!!
!!
!!
!!
!!
!!
Conversion: 1 in wc = .25 kPa
NOTE:
Natural gas data is based on 0.60 specific gravity. For fuels with different specific gravity consult the National Fuel Gas Code ANSI Z223.1/NFPA
54
!
2009 or National Standard of Canada, Natural Gas And Propane Installation Code CSA B149.1
!
05.
*
In the USA,
derating of these furnaces at 2% (Natural Gas) and 4% (Propane Gas) has been tested and design
!
certified by CSA.
In Canada
, the input rating must be derated 5% (Natural Gas) and 10% (Propane Gas) for altitudes of 2,000 to 4,500 (610 to
1372m) above sea level. Use the 2001 to 3000 (610 to 914m) column in
Table 6
and
Table 7
.
Table 7
PROPANE GAS MANIFOLD PRESSURE (in wc)
HEATING VALUE
at ALTITUDE
BTU/CU. FT.
MEAN ELEVATION ABOVE SEA LEVEL
!
ft(m)
0 to 2000
(0 to 610)
2001 to 3000
*
(610 to 914)
*
3001 to 4000
(915 to 1219)
4001 to 5000
(1220 to 1524)
5001 to 6000
(1524 to 1829)
6001 to 7000
(1829 to 2134)
7001 to 8000
(2134 to 2438)
2500
10.0
10.0
9.0
10.0
9.4
8.5
10.0
Orifice Size
#54
#54
#54
#55
#55
#55
#56
Conversion: 1 in wc = .25 kPa
NOTE:
Propane data is based on 1.53 specific gravity. For fuels with different specific gravity consult the National Fuel Gas Code ANSI Z223.1/NFPA
54
!
2009 or National Standard Of Canada, Natural Gas And Propane Installation Code CSA B149.1
!
05.
*
In the USA,
derating of these furnaces at 2% (Natural Gas) and 4% (Propane Gas) has been tested and design
!
certified by CSA.
In Canada
, the input rating must be derated 5% (Natural Gas) and 10% (Propane Gas) for altitudes of 2,000 to 4,500 (610 to
1372m) above sea level. Use the 2001 to 3000 (610 to 914m) column in
Table 6
and
Table 7
.
The burner orifice part nos. are as follows:
Orifice #41
1096942
Orifice #42
1011351
Orifice #43
1011377
Orifice #44
1011352
Orifice #45
1011353
Orifice #54
1011376
Orifice #55
1011354
Orifice #56
1011355
High Altitude Air Pressure Switch
The factory
!
installed pressure switch need NOT be changed for
any furnace installations from sea level up to and including 8,000
′
(2438m) altitude
Changing Orifices
1. After disconnecting power and gas supply to the furnace,
remove the burner compartment door, exposing the burner
compartment.
2. Disconnect gas line from gas valve so manifold can be
removed.
3. Disconnect wiring at gas valve. Be sure to note the proper
location of all electrical wiring before being disconnected.
4. Remove the four (4) screws holding the manifold and gas
valve to the manifold supports. Do not discard any screws.
See
Figure 33.
5. Carefully remove the manifold assembly.
6. Remove the orifices from the manifold and replace them with
proper sized orifices. See
Figure 34.
7. Tighten orifices so they are seated and gas
!
tight. See
Figure 34.
8. Reassemble all parts in reverse order as removed. Be sure to
engage the main burner orifices in the proper openings in the
burners.
National Excelsior Company
www.excelsiorhvac.com
Subject to change without notice.
