GAS PIPING
Natural Gas Connection
IMPORTANT NOTE: This unit is factory set to operate on natural
gas at the altitudes shown on the rating plate.
TO AVOID PROPERTY DAMAGE, PERSONAL INJURY OR DEATH WHEN EITHER
USING PROPANE GAS ALONE OR AT HIGHER ALTITUDES, OBTAIN AND INSTALL
THE PROPER CONVERSION KIT(S). FAILURE TO DO SO CAN RESULT IN
UNSATISFACTORY OPERATION AND/OR EQUIPMENT DAMAGE. HLGH ALTITUDE
KITS ARE FOR U . S . INSTALLATIONS ONLY AND ARE NOT APPROVED FOR USE
IN CANADA.
The rating plate is stamped with the model number, type of gas and
gas input rating. Make sure the unit is equipped to operate on the
type of gas available. Conversion to LP gas is permitted with the
use of the factory authorized conversion kit LPT-OOA.
Inlet Gas Pressure Must Not Exceed the Maximum Value Shown in Table
Above.
The minimum supply pressure should not vary from that shown in
the table above because this could prevent the unit from having
dependable ignition. In addition, gas input to the burners must not
exceed the rated input shown on the rating plate. Overfiring of the
unit could result in premature heat exchanger failure.
HIGH ALTITUDE DERATE (U.S. INSTALLATIONS ONLY)
IMPORTANT NOTE: The gas/electric units naturally derate with al-
titude. Do not attempt to increase the firing rate by changing orifices
or increasing the manifold pressure. This can cause poor combus-
tion and equipment failure. At all altitudes, the manifold pressure
must be within 0-3 inches W.C. of that listed on the nameplate for
the fuel used. At all altitudes and with either fuel, the air tempera-
ture rise must be within the range listed on the unit nameplate.
Refer to the Installation Manual provided with the LP kit for
conversion from natural gas to propane gas and for altitude
adjustments.
PIPING
IMPORTANT NOTE: To avoid possible unsatisfactory operation or
equipment damage due to under firing of equipment, do not under-
size the natural/propane gas piping from the meter/tank to the unit.
When sizing a trunk line as shown in Table 2, include all appliances
on that line that could be operated simultaneously.
The rating plate is stamped with the model number, type of gas and
gas input rating. Make sure the unit is equipped to operate on the
type of gas available. The gas line installation must comply with
local codes, or in the absence of local codes, with the latest edition
of the National Fuel Gas Code NFPA54/ANSI Z223.1.
Heating Value of Gas (BTU/Cubic_Foot)
Refer to the Proper Piping Practice drawing for the general layout at
the unit. The following rules apply:
1. Use black iron pipe and fittings for the supply piping. The
use of a flex connector and/or copper piping is permitted as
long as it is in agreement with local codes.
2. Use pipe joint compound on male threads only. Pipe joint
compound must be resistant to the action of the fuel used.
3. Use ground joint unions.
4. Install a drip leg to trap dirt and moisture before it can enter
the gas valve. The drip leg must be a minimum of three inches
long.
5. Use two pipe wrenches when making connection to the gas
valve to keep it from turning.
6. Install a manual shut-off valve in a convenient location (within
six feet of unit) between the meter and the unit.
7. Tighten all joints securely.
8. The unit must be connected to the building piping by one of
the following methods:
Rigid metallic pipe and fittings
• Semirigid metallic tubing and metallic fittings (Aluminum alloy
tubing must not be used in exterior locations)
Listed gas appliance connectors used in accordance with
the terms of their listing that are completely in the same
room as the equipment
• In the prior two methods above the connector or tubing
must be protected from physical and thermal damage.
Aluminum alloy tubing and connectors must be coated to
protect against external corrosion when in contact with
masonry, plaster or insulation or are subject to repeated
wettings by liquids (water - not rain water, detergents or
sewage)
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