Gas Supply And Piping; G S P; Vac Humidifier; High Altitude Derate - Goodman MH8 Installation Instructions Manual

24 V H
AC UMIDIFIER
The yellow wire connected to the I.D. Blower pressure switch
is powered anytime the pressure switch is closed and
provides 24 VAC humidifier control. Remove the yellow wire
and connect the supplied brown jumper wire to the pressure
switch terminal. Reconnect the yellow wire to the "piggyback"
terminal on the brown jumper and then connect the 24 VAC
line of the humidifier to the stripped end of the brown wire.
Using a wire nut or a field-supplied quick connect terminal
can make this connection. The wiring must conform to all
local and national codes. Connect the COM side of the
humidifier to the B/C terminal on the furnace control board
(or to the COM side of the 24 VAC transformer). DO NOT
CONNECT 115V HUMIDIFIER TO THESE TERMINALS.
G S P
AS UPPLY AND
The furnace rating plate includes the approved furnace gas in-
put rating and gas types. The furnace must be equipped to
operate on the type of gas applied. This includes any conver-
sion kits required for alternate fuels and/or high altitude.
T
O PREVENT UNRELIABLE OPERATION
INLET GAS SUPPLY PRESSURE
RATING PLATE WITH ALL OTHER
.
OPERATING
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 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.
Propane Gas Minimum: 11.0" w.c.
NOTE: Adjusting the minimum supply pressure below the limits
in the above table could lead to unreliable ignition. Gas input to
the burners must not exceed the rated input shown on the
rating plate. Overfiring of the furnace can result in premature
heat exchanger failure. Gas pressures in excess of 13 inches
water column can also cause permanent damage to the gas
valve.
At all altitudes, the manifold pressure must be within 0.3 inches
w.c. of that listed in the Specification Sheet applicable to your
model for the fuel used. At all altitudes and with either fuel, the
air temperature rise must be within the range listed on the fur-
nace nameplate. Should this appliance be converted to LP,
refer to the instructions included in the factory authorized LP
conversion kit.
H A D
IGH LTITUDE ERATE
IMPORTANT NOTE: The furnace will naturally derate itself with
altitude. Do not attempt to increase the firing rate by changing
orifices or increasing the manifold pressure. This can cause
poor combustion and equipment failure.
IPING
CAUTION
OR EQUIPMENT DAMAGE
MUST BE AS SPECIFIED ON THE
HOUSEHOLD GAS FIRED APPLIANCES
Maximum:10.0" w.c.
Maximum:13.0" w.c.
High altitude installations may require both a pressure switch
and an orifice change. These changes are necessary to com-
pensate for the natural reduction in the density of both the gas
fuel and the combustion air at higher altitude.
For installations above 7000 feet, please refer to your distribu-
tor for required kit(s).
Contact the distributor for a tabular listing of appropriate
manufacturer's kits for propane gas and/or high altitude instal-
lations. The indicated kits must be used to insure safe and
proper furnace operation. All conversions must be performed
by a qualified installer, or service agency.
P G
ROPANE
P
OSSIBLE PROPERTY
OCCUR IF THE
APPROPRIATE
FURNACE OPERATION
QUALIFIED INSTALLER
This unit is configured for natural gas. The appropriate
,
THE
manufacturer's propane gas conversion kit, must be applied for
UNIT
propane gas installations. Refer to the "Propane Gas and/or
High Altitude Installations" section for details.
Models using Single Stage Gas Valves
Altitude
0-7000
NOTE: In Canada, gas furnaces are certified to 4500 feet.
NOTE: GMS81405DN** models utilize #43 orifices in Natural gas
applications.
Models using 2-Stage Gas Valves
Gas Altitude
Natural
0-7000
Propane
NOTE: In Canada, gas furnaces are only certified to 4500 feet.
NOTE: GMH81405DN** models utilize #43 orifices in Natural gas
applications.
19
G S
AS UPPLY AND
C
AS ONVERSION
WARNING
,
DAMAGE PERSONAL INJURY
CORRECT CONVERSION KITS ARE
KITS MUST BE APPLIED TO ENSURE
. A
LL CONVERSIONS MUST
.
OR SERVICE AGENCY
Gas Kit Orifice
Natural None #45
Propane LPT-03 #55
Manifold Pressure Pressure
Kit Orifice
High
Stage
None #45 3.5" w.c. 1.9" w.c.
LPM-06 #55 10.0" w.c. 6.0" w.c.
P
IPING
OR DEATH MAY
. T
NOT INSTALLED HE
SAFE AND PROPER
BE PERFORMED BY A
Manifo ld Pressure
Pressu re Switch
3.5" w.c.
None
10.0" w.c.
Switch
Low
Change
Stage
None
None