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NOTE: Do not remove the gas valve inlet plug before the gas
line is installed. Replace if water or debris has been introduced.
INLET GAS SUPPLY PRESSURE
Natural Gas
Minimum: 4.5" w.c.
Propane Gas
Minimum: 11.0" w.c.
NOTE: Adjusting the minimum supply pressure below the limits
in the above table could lead to unreliable ignition. Gas input to
the burners must not exceed the rated input shown on the
rating plate. Overfiring of the furnace can result in premature
heat exchanger failure. Gas pressures in excess of 13 inches
water column can also cause permanent damage to the gas
valve.
At all altitudes, the manifold pressure must be within 0.3 inches
w.c. of that listed in the Specification Sheet applicable to your
model for the fuel used. At all altitudes and with either fuel, the
air temperature rise must be within the range listed on the fur-
nace nameplate. Should this appliance be converted to LP,
refer to the instructions included in the factory authorized LP
conversion kit.
H
A
D
IGH
LTITUDE
ERATE
IMPORTANT NOTE: The furnace will naturally derate itself with
altitude. Do not attempt to increase the firing rate by changing
orifices or increasing the manifold pressure. This can cause
poor combustion and equipment failure.
High altitude installations may require both a pressure switch
and an orifice change. These changes are necessary to com-
pensate for the natural reduction in the density of both the gas
fuel and the combustion air at higher altitude.
For installations above 7000 feet, please refer to your distribu-
tor for required kit(s).
Gas
Altitude
Kit
Orifice
Natural
None
#45
0-7000
Propane
LPM-06
#55
NOTE: In Canada, gas furnaces are only certified to 4500 feet.
Consult the furnace Specification Sheet for appropriate
manufacturer's kits for propane gas and/or high altitude instal-
lations. The indicated kits must be used to insure safe and
proper furnace operation. All conversions must be performed
by a qualified installer, or service agency.
P
G
C
ROPANE
AS
ONVERSION
P
OSSIBLE
PROPERTY
DAMAGE
OCCUR
IF
THE
CORRECT
CONVERSION
APPROPRIATE
KITS
MUST
BE
APPLIED
. A
FURNACE
OPERATION
LL
CONVERSIONS
QUALIFIED
INSTALLER
OR
SERVICE
Maximum: 10.0" w.c.
Maximum: 13.0" w.c.
Manifold Pressure
Pressure
High Stage Low Stage
Switch Change
3.5" w.c.
1.9" w.c.
10.0" w.c.
6.0" w.c.
WARNING
,
PERSONAL
INJURY
OR
DEATH
MAY
KITS
ARE
NOT
INSTALLED
TO
ENSURE
SAFE
AND
PROPER
MUST
BE
PERFORMED
.
AGENCY
This unit is configured for natural gas. The appropriate
manufacturer's propane gas conversion kit, must be applied for
propane gas installations. Refer to the "Propane Gas and/or
High Altitude Installations" section for details.
If converting to LP gas, it is recommended that an LPLP0* kit
also be installed. The use of this kit will prevent the furnace
from firing when the LP gas supply pressure is too low to sup-
port proper combustion.
Consult the furnace Specification Sheet for a listing of appropri-
ate manufacturer's kits for propane gas and/or high altitude in-
stallations. The indicated kits must be used to insure safe and
proper furnace operation. All conversions must be performed
by a qualified installer, or service agency.
G
P
C
AS
IPING
T
O
AVOID
POSSIBLE
DAMAGE
DUE
/
OF
NATURAL
/
THE
METER
TANK
When sizing a trunk line, be sure to include all appliances
which will operate simultaneously.
The gas piping supplying the furnace must be properly sized
based on the gas flow required, specific gravity of the gas, and
length of the run. The gas line installation must comply with
local codes, or in their absence, with the latest edition of the
National Fuel Gas Code, NFPA 54/ANSI Z223.1.
Length of
Pipe in Feet
10
20
30
40
50
60
None
70
80
None
90
100
(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on
0.60 Specific Gravity Gas)
CFH = BTUH Furnace Input
Heating Value of Gas (BTU/Cubic Foot)
To connect the furnace to the building's gas piping, the installer
must supply a ground joint union, drip leg, manual shutoff valve,
and line and fittings to connect to gas valve. In some cases,
the installer may also need to supply a transition piece from 1/
2" pipe to a larger pipe size.
The following stipulations apply when connecting gas piping.
•
Gas piping must be supported external to the furnace
. T
HE
cabinet so that the weight of the gas line does not
distort the burner rack, manifold or gas valve.
BY
A
20
ONNECTIONS
WARNING
UNSATISFACTORY
OPERATION
TO
UNDERFIRING
OR
EQUIPMENT
PROPANE
GAS
PIPING
NEEDED
WHEN
.
TO
THE
FURNACE
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Nominal Black Pipe Size
1/2"
3/4"
1"
132
278
520
92
190
350
73
152
285
63
130
245
56
115
215
50
105
195
46
96
180
43
90
170
40
84
160
38
79
150
OF
EQUIPMENT
,
USE
THE
PROPER
SIZE
RUNNING
PIPE
FROM
1 1/4"
1 1/2"
1050
1600
730
1100
590
980
500
760
440
670
400
610
370
560
350
530
320
490
305
460
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