Fossil Fuel Applications; Gas Supply And Piping; High Altitude Derate; Propane Gas Conversion - Goodman *MSS9* Installation Instructions Manual

F F A
OSSIL UEL PPLICATIONS
This furnace can be used in conjunction with a heat pump in a fossil
fuel application. A fossil fuel application refers to a combined gas
furnace and heat pump installation which uses an outdoor tem-
perature sensor to determine the most cost efficient means of
heating (heat pump or gas furnace).
Strictly follow the wiring guidelines in the fossil fuel kit installation
instructions. All furnace connections must be made to the furnace
two-stage integrated control module and the "FURNACE" terminal strip on the fossil fuel control board.
G S P
AS UPPL Y AND IPING
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 conversion kits required
for alternate fuels and/or high altitude.
Inlet gas supply pressures must be maintained within the ranges
specified in the following table. The supply pressure must be constant and available with all other household gas fired appliances
operating. The minimum gas supply pressure must be maintained to prevent unreliable ignition. The maximum must not be
exceeded to prevent unit overfiring.
H A D
IGH LTITUDE ERATE
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 pressure 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
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
Specification Sheet for pressure switch.
P G C
ROPANE AS ONVERSION
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 in-
staller, or service agency.
G V
AS ALVE
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 convertible 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 Procedure & Adjustment for use of this control during start up and shut down
periods.
HIGH VOLTAGE !
T
O AVOID PERSONAL INJURY OR DEATH DUE TO
,
ELECTRICAL SHOCK DISCONNECT ELECTRICAL POWER
BEFORE SERVICING OR CHANGING ANY ELECTRICAL
.
WIRING
T
O PREVENT UNRELIABLE OPERATION OR EQUIPMENT DAMAGE
GAS MANIFOLD PRESSURE MUST BE AS SPECIFIED ON THE UNIT RATING
. O
PLATE NLY MINOR ADJUSTMENTS SHOULD BE MADE BY ADJUSTING
THE GAS VALVE PRESSURE REGULATOR
content of the fuel used. Consult the furnace
3
P
OSSIBLE PROPERTY DAMAGE
OCCUR IF THE CORRECT CONVERSION KITS ARE NOT INSTALLED
APPROPRIATE KITS MUST BE APPLIED TO ENSURE SAFE AND PROPER
. A
FURNACE OPERATION
QUALIFIED INSTALLER OR SERVICE AGENCY
25
WARNING
CAUTION
.
content of the derated gas and the
3
WARNING
,
PERSONAL INJURY OR DEATH MAY
LL CONVERSIONS MUST BE PERFORMED BY A
.
,
THE
. T
HE