Page 11
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 6.
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.
FIGURE 6
GROUND
JOINT UNION
DRIP LEG
MANUAL
MAIN SHUT−OFF VALVE
(Furnished by Installer)
GAS FLOW
1/8 NPT
PLUGGED
TAP
GAS SUPPLY CONNECTION
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.
CAUTION
DO NOT use matches, candles, flame or other
sources of ignition to check for gas leaks.
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).
IMPORTANT
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 fig-
ure 7.
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.
FIGURE 7
CAP
GAS SUPPLY TO UNIT HEATER
UNIT HEATER
MANUAL MAIN SHUT−OFF
VALVE WILL NOT HOLD
NORMAL TEST
PRESSURES OF 1/2 psig
(3.45kPa) OR HIGHER
DISCONNECT GAS
VALVE WHEN TEST
PRESSURES OF
1/2 psig (3.45kPa)
OR HIGHER WILL
BE USED.
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.
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