Vac Hum; Gas Supply And Piping; General; High Altitude Derate - Goodman GME8 Installation Instructions Manual

Control Module
Hot 120 VAC
Optional
Accessories
If it is necessary for the installer to supply additional line voltage
wiring to the inside of the furnace, the wiring must conform to all
local codes, and have a minimum temperature rating of 105°C.
All line voltage wire splices must be made inside the furnace
junction box.
The integrated control module electronic air cleaner terminals
(EAC) are energized with 115 volts whenever the circulator blower
is energized.
24 V H
AC UM
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.
IX. GAS SUPPLY AND PIPING
G
ENERAL
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.
T
O PREVENT UNRELIABLE OPERATION OR EQUIPMENT DAMAGE
I
NLET 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 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.
Inlet Gas Supply Pressure
Natural Gas
Minimum: 5.0" w.c.
Propane Gas Minimum: 11.0" w.c.
Neutral 120 VAC
Air Cleaner
CAUTION
Maximum:10.0" w.c.
Maximum:13.0" 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 furnace
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
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.
When this furnace is installed at high altitude, the appropriate
High Altitude orifice kit must be applied. The furnace is supplied
with orifices sized for natural gas at altitudes up to 4,500 feet
using a heating value of approximately 1,000 Btu/hr, and should
not normally require change. Most cases will not require a change
at altitudes up to 7,500 feet. For use at altitudes in excess of 4,500
feet, refer to the following table for maximum input rates based on
altitude. Contact your local gas utility for the heating value of the
gas. Refer to National Fuel Gas Code ANSI Z223.1 and the
following section to calculate firing rates.
Maximium Firing Rates At Altitude
Altitude (ft)
5,000
7,500
10,000
* Firing rates may be lower than listed in table
It is important to check and adjust the input rate of the furnace to
prevent an overfiring situation. Overfiring can cause premature
heat exchanger failure. The input is controlled by the supply
pressure, orifice size, manifold pressure and heating (calorific)
value of the gas.
The supply pressure must be measured with this and all other
gas burning appliances in operation. The supply pressure must
,
THE
be adjusted to the pressure range stated on the rating plate.
Applications for altitudes in excess of 4,500 feet usually require
an orifice change.
A H
LTERNATE IGH
Alternately standard derate for altitude from National Fuel Gas
Code ANSI Z223.1 of 4% per 1000' may be taken. Refer to the
most recent version of ASNI Z223.1 for correct gas orifice. The
orifices must be selected using the table below. The furnace derate
is 4% for each 1,000 feet above sea level. This table is based
upon a heating value of approximately 1,000 Btu/ft
17
ERATE
Model (Kbtu/hr)
70 90
58,500 78,000
52,500 70,000
51,000 68,000
A D
LTITUDE ERATE
115
97,500
87,500
77,000
3