Gas Connection
When connecting gas supply, the length of the run from
the meter must be considered in determining the pipe
size to avoid excessive pressure drop. A line pressure
of 7" w.c. (178 mm w.c.) for natural gas should be
maintained when sizing piping. For correct sizing of
piping, consult the utility having jurisdiction.
A drip leg should be installed in the vertical pipe run to
the unit. In some localities, codes may require that a
manual main shutoff valve and union (furnished by
installer) be installed external to the unit. Union must
be of the ground joint type. See figure 7.
A 1/8" NPT plugged tap must be installed immediately
upstream of the gas supply connection to the heater.
NOTE
− Compounds used on threaded joints of gas
piping must be resistant to the actions of liquefied
petroleum gases.
GAS SUPPLY CONNECTION
MANUAL
MAIN SHUT−OFF VALVE
(Furnished by Installer)
GROUND
JOINT UNION
1/8 NPT
PLUGGED
GAS FLOW
TAP
DRIP LEG
FIGURE 7
Leak Check
After gas piping is completed, carefully check all piping
connections, (field and factory), for gas leaks. Use a
soap solution or other preferred means.
The appliance must be isolated from the gas supply
piping system by closing its individual manual gas
shutoff valve during any pressure testing of the gas
supply system at test pressures equal to or less than
1/2 psig (3.45kPa).
NOTE
− In case emergency shutdown is required, shut
down main gas valve and disconnect main power to unit.
These devices should be properly labeled by the installer.
GAS SUPPLY TO UNIT HEATER
MANUAL MAIN SHUT−OFF
DISCONNECT GAS
VALVE WILL NOT HOLD
NORMAL TEST
VALVE WHEN TEST
PRESSURES OF 1/2 psig
PRESSURES OF
1/2 psig (3.45kPa)
(3.45kPa) OR HIGHER
OR HIGHER WILL
BE USED.
CAP
UNIT HEATER
FIGURE 8
Unit Start−Up
FOR YOUR SAFETY READ BEFORE LIGHTING
WARNING
Electric shock hazard. Can cause injury
or death. Do not use this appliance if any
part has been under water. Immedi-ately
call a qualified service technician to
inspect the furnace and to replace any
part of the control system and any gas
control which has been under wa-ter.
WARNING
Danger of explosion. Can cause injury or
product or property damage. If
overheating occurs or if gas supply fails
to shut off, shut off the manual gas valve
to the appliance before shutting off
electrical supply
The heater and its individual shut off valve must be
disconnected from the gas supply piping system
during any pressure testing of that system at test
pressures in excess of 1/2 psig (3.45kPa). See
figure 8.
IMPORTANT
DO NOT use matches, candles, flame or other
sources of ignition to check for gas leaks.
CAUTION
Electric shock hazard. Can cause injury
or death. Do not use this appliance if any
part has been under water. Immediately
call a qualified service technician to
inspect the furnace and to replace any
part of the control system and any gas
control which has been under water.
Danger of explosion. Can cause injury or
product or property damage. If overheating
occurs or if gas supply fails to shut off, shut
off the manual gas valve to the appliance
before shutting off electrical supply.
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