Amana GUIA Series Service Instructions Manual page 56

PRODUCT DESIGN
Gas Supply and Piping
The furnace rating plate includes the approved furnace gas
input rating and gas types. The furnace must be equipped to
operate on the type of gas applied. This includes any con-
version kits required for alternate fuels and/or high altitude.
CAUTION
To prevent unreliable operation or equipment dam-
age, the inlet gas supply pressure must be as specified
on the unit rating plate with all other household gas
fired appliances operating.
Inlet gas supply pressures must be maintained within the
ranges specified below. The supply pressure must be con-
stant and available with all other household gas fired appli-
ances operating. The minimum gas supply pressure must
be maintained to prevent unreliable ignition. The maximum
must not be exceeded to prevent unit overfiring.
Inlet Gas Supply Pressure
Natural Gas Minimum: 5.0" W.C. Maximum :10.0" W.C.
Propane Gas
Minimum:11.0" W.C. Maximum :13.0" W.C.
HIGH ALTITUDE DERATE
When this furnace is installed at high altitude, the appropri-
ate High Altitude orifice kit must be applied. This is required
due to the natural reduction in the density of both the gas
fuel and combustion air as altitude increases. The kit will
provide the proper design certified input rate within the speci-
fied altitude range.
High altitude kits are purchased according to the installa-
tion altitude and usage of either natural or propane gas. Refer
to the product Specification Sheet or Technical Manual for a
tabular listing of appropriate altitude ranges and correspond-
ing manufacturer's high altitude (Natural, Propane gas, and/
or Pressure Switch) kits.
Do not derate the furnace by adjusting the manifold pres-
sure to a lower pressure than specified on the furnace rating
plate. The combination of the lower air density and a lower
manifold pressure will prohibit the burner orifice from draw-
ing the proper amount of air into the burner. This may cause
incomplete combustion, flashback, and possible yellow tip-
ping.
In some areas the gas supplier may artificially derate the
gas in an effort to compensate for the effects of altitude. If
the gas is artificially derated, the appropriate orifice size
must be determined based upon the BTU/ft
derated gas and the altitude. Refer to the National Fuel Gas
Code, NFPA 54/ANSI Z223.1, and information provided by
the gas supplier to determine the proper orifice size.
A different pressure switch may be required at high altitude
regardless of the BTU/ft 3
the product Specification Sheet or Technical Manual for a
tabular listing of appropriate altitude ranges and correspond-
ing manufacturer's pressure switch kits.
56
Rev. 1
3 content of the
content of the fuel used. Refer to
Propane Gas Conversion
WARNING
Possible death, personal injury or property damage
may occur if the correct conversion kits are not installed.
The appropriate kits must be applied to insure safe
and proper furnace operation. All conversions must be
performed by a qualified installer or service 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.
Gas Valve
This unit is equipped with a 24 volt gas valve controlled dur-
ing furnace operation by the integrated control module. As
shipped, the valve is configured for natural gas. The valve is
field convertible for use with propane gas by using the ap-
propriate propane gas conversion kit. Taps for measuring
the gas supply pressure and manifold pressure are provided
on the valve.
The gas valve has a manual ON/OFF control located on the
valve itself. This control may be set only to the "ON" or "OFF"
position. Refer to the Lighting Instructions Label or the "Put-
ting the Furnace Into Operation" section of this manual or
the installation instructions for use of this control during start
up and shut down periods.
GAS PIPING CONNECTIONS
CAUTION
To avoid possible unsatisfactory operation or equip-
ment damage due to underfiring of equipment, use
the proper size of natural/propane gas piping needed
when running pipe from the meter/tank to the furnace.
When sizing a trunk line, be sure to include all appliances
which will operate simultaneously when sizing a trunk line.
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.