30
Conversion
Conversion of this furnace to use LP/propane
gas must be made by qualifi ed service person-
nel, using only approved parts.
High Altitude Application
High altitude application with this furnace can
be fi eld performed by a simple adjustment of
manifold pressure, and if necessary changing
the orifi ces. The changes required depend on
the installation altitude and the heating value
of the gas. The gas heating value based on sea
level can be obtained from your local gas util-
ity. The heating value of gas at high altitude is
always lower than the sea level heating value.
The heating values used in Tables 8 & 9 are
based on sea level values.
Natural Gas High Altitude
Conversion
All factory shipped furnaces are ready to operate
between zero and 4999 ft. above sea level. For
higher altitudes (between 5000 and 10,000 ft.
above sea level), conversion can be achieved
simply by adjusting the furnace manifold pres-
sure as shown in Table 8.
LP/Propane Gas Sea Level and
High Altitude Conversion
IMPORTANT NOTE: When converting a low
NOx furnace from Natural gas to LP/pro-
pane gas, it is necessary to remove the NOx
Baffl es from the furnace.
Conversion of this furnace to utilize LP/propane
gas must be made by qualifi ed service person-
nel, using factory authorized or approved parts.
Conversion to LP/propane gas can be accom-
plished by fi rst replacing the natural gas orifi ces
with the appropriate LP/propane orifi ces shown
in Table 10 or 11. Note: for installations between
zero and 5000 ft. above sea level, a #54 or #55
drill size orifi ce should be used depending upon
the rated fi ring rate of the unit (see Table 10 or
11). However for installations above 5000 ft.
above sea level, a # 55 or #56 drill size orifi ce
should be used. After changing the orifi ces, use
Table 9 to determine the appropriate manifold
pressure for your installation.
Conversion to LP/propane, sea level, and high
altitude is detailed in the installation instructions
provided with the conversion kit. Approved con-
version kits are listed below.
United States LP/Propane Gas Sea Level and
High Altitude Conversion Kit - P/N 904090A
This kit is for LP/propane conversion in the
United States at altitudes between zero and
10,000 ft. above sea level. Follow the installa-
tion instructions supplied with the kit for proper
installation.
* Time-delay fuses or HACR-type circuit breakers are required.
Table 12. Electrical Data
Furnace Cabinet Nominal Maximum Minimum Maximum on Minimum Maximum on
Input Width Electrical Operating Operating Furnace Wire Fuse or Circuit
(Btuh) (in.) Supply Voltage Voltage Amperes Gauge Breaker Amps*
40,000 14.25 115-60-1 127 103 7.8 14 15
60,000 14.25 115-60-1 127 103 7.8 14 15
80,000 19.75 115-60-1 127 103 9.7 14 15
100,000 19.75 115-60-1 127 103 9.7 14 15
120,000 22.50 115-60-1 127 103 12.9 12 20
Thermostat
Wire
Gauge
Recommended Maximum Thermostat
Wire Length
2-wire 4 or 5-wire
(heating) (cooling)
24 55 ft. 25 ft.
22 90 ft. 45 ft.
20 140 ft. 70 ft.
18 225 ft. 110 ft.