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364861-UIM-B-0708
10 Johnson Controls Unitary Products
The furnace must be isolated from the gas supply piping system by
closing its individual external manual shutoff valve during any pressure
testing of the gas supply piping system at pressures equal to or less
than 1/2 psig (3.5 kPa).
Gas piping may be connected from either side of the furnace using any
of the gas pipe entry knockouts on both sides of the furnace. Refer to
Figure 12, "Dimensions".
GAS ORIFICE CONVERSION FOR PROPANE (LP)
This furnace is constructed at the factory for natural gas-fired operation,
but may be converted to operate on propane (LP) gas by using a fac-
tory-supplied LP conversion kit. Follow the instructions supplied with
the LP kit.
HIGH ALTITUDE GAS ORIFICE CONVERSION
This furnace is constructed at the factory for natural gas-fired operation
at 0 –5,000 feet (0-m – 1,524 m) above sea level.
The manifold pressure must be changed in order to maintain proper
and safe operation when the furnace is installed in a location where the
altitude is greater than 5,000 feet (1,524 m) above sea level. Refer to
Table 5, "Nominal Manifold Pressure - High Fire" for proper manifold
pressure settings.
HIGH ALTITUDE PRESSURE SWITCH CONVERSION
For installation where the altitude is less than 5,000 feet (1,524m), it is
not required that the pressure switch be changed unless you are in an
area subject to low pressure inversions.
SECTION V: ELECTRICAL POWER
ELECTRICAL POWER CONNECTIONS
Field wiring to the unit must be grounded. Electric wires that are field
installed shall conform to the temperature limitation for 63°F (35°C) rise
wire when installed in accordance with instructions. Refer to Table 6,
"Ratings & Physical / Electrical Data" in these instructions for specific
furnace electrical data.
The gas valve body is a very thin casting that cannot take any
external pressure. Never apply a pipe wrench to the body of the gas
valve when installing piping. A wrench must be placed on the octa-
gon hub located on the gas inlet side of the valve. Placing a wrench
to the body of the gas valve will damage the valve causing improper
operation and/or the valve to leak.
Table 5: Nominal Manifold Pressure - High Fire
Manifold Pressures (in wc) Manifold Pressures (kpa)
Altitude (feet) Altitude (m)
0-7999 8000-8999 9000-9999 0-2437 2438-2742 2743-3048
Gas Heating Value
(BTU/cu ft.)
800 3.5 3.5 3.5
Gas Heating Value
(MJ/cu m)
29.8 0.87 0.87 0.87
850 3.5 3.5 3.5 31.7 0.87 0.87 0.87
900 3.5 3.5 3.5 33.5 0.87 0.87 0.87
950 3.5 3.5 3.3 35.4 0.87 0.87 0.81
1000 3.5 3.2 2.9 37.3 0.87 0.80 0.73
1050 3.5 2.9 2.7 39.1 0.87 0.73 0.67
1100 3.2 2.7 2.4 41.0 0.80 0.66 0.61
2500 (LP) 9.8 8.2 7.5 93.2 (LP) 2.44 2.03 1.86
PROPANE AND HIGH ALTITUDE CONVERSION KITS
It is very important to choose the correct kit and/or gas orifices for the altitude and the type of gas for which the furnace is being installed.
Only use natural gas in furnaces designed for natural gas. Only use propane (LP) gas for furnaces that have been properly converted to use pro-
pane (LP) gas. Do not use this furnace with butane gas.
Incorrect gas orifices or a furnace that has been improperly converted will create an extremely dangerous condition resulting in premature heat
exchanger failure, excessive sooting, high levels of carbon monoxide, personal injury, property damage, a fire hazard and/or death.
High altitude and propane (LP) conversions are required in order for the appliance to satisfactory meet the application.
An authorized distributor or dealer must make all gas conversions.
In Canada, a certified conversion station or other qualified agency, using factory specified and/or approved parts, must perform the conversion.
The installer must take every precaution to insure that the furnace has been converted to the proper gas orifice size when the furnace is installed.
Do not attempt to drill out any orifices to obtain the proper orifice size. Drilling out a gas orifice will cause misalignment of the burner flames,
causing premature heat exchanger burnout, high levels of carbon monoxide, excessive sooting, a fire hazard, personal injury, property damage
and/or death.
Use copper conductors only.