High Altitude Derate; Propane Gas Conversion; Gas Piping Connections - Maytag Amana MES9 Series Installation Instructions Manual

not be exceeded to prevent unit overfiring.
T
O AVOID POSSIBLE UNSATISFACTORY OPERATION OF EQUIPMENT
DAMAGE DUE TO UNDERFIRING OR EQUIPMENT
/
OF NATURAL PROPANE GAS PIPING NEEDED WHEN RUNNING PIPE FROM
/
THE METER TANK TO THE FURNACE

High Altitude Derate

When this furnace is installed at high altitude, the appropriate
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 specified altitude
range.
High altitude kits are purchased according to the installation
altitude and usage of either natural or propane gas. Consult
the furnace Specification Sheet for appropriate 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 drawing the proper amount of air into the burner. This
may cause incomplete combustion, flashback, and possible
yellow tipping.
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 furnace Specification Sheet for pressure switch.

Propane Gas Conversion

This unit is configured for natural gas. To operate this furnace
on L.P. gas, an LPM-07 LP Conversion kit must be used.
The indicated kit must be used to insure safe and proper
furnace operation. All conversions must be performed by
a qualified installer, or service agency.
Gas Valve
This unit is equipped with a 24 volt gas valve controlled during
furnace operation by the integrated control module. As shipped,
the valve is configured for natural gas. The valve is field convert-
ible for use with propane gas by replacing the regulator spring
with a propane gas spring from an appropriate manufacturer's
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 Startup
WARNING
,
USE THE PROPER SIZE
.
content of the
3
content of the fuel used. Consult
Procedure & Adjustment for use of this control during start
up and shut down periods.

Gas Piping Connections

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 or CAN/CSA
B149.1-15 in Canada.
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 tran-
sition piece from 1/2" pipe to a larger pipe size.
The following stipulations apply when connecting gas piping.
Refer to Gas Piping Connections figure for typical gas line
connections to the furnace.
• Gas piping must be supported external to the furnace
cabinet so that the weight of the gas line does not
distort the burner rack, manifold or gas valve.
•
Use black iron or steel pipe and fittings for building
piping. Where possible, use new pipe that is properly
chamfered, reamed, and free of burrs and chips. If
old pipe is used, be sure it is clean and free of rust,
scale, burrs, chips, and old pipe joint compound.
•
Use pipe joint compound on male threads ONLY.
Always use pipe joint compound (pipe dope) that is
APPROVED FOR ALL GASSES. DO NOT apply compound
to the first two threads.
•
Use ground joint unions.
•
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.
•
Install a 1/8" NPT pipe plug fitting, accessible for test
gauge connection, immediately upstream of the gas
supply connection to the furnace.
•
Always use a back-up wrench when making the
connection to the gas valve to keep it from turning.
The orientation of the gas valve on the manifold must
be maintained as shipped from the factory. Maximum
torque for the gas valve connection is 375 in-lbs;
excessive over-tightening may damage the gas valve.
•
Install a manual shutoff valve between the gas meter
and unit within six feet of the unit. If a union is
installed, the union must be downstream of the
manual shutoff valve, between the shutoff valve and
the furnace.
•
Tighten all joints securely.
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