Lennox SCA 010 Installation, Operation & Maintenance Manual page 44

GAS BURNER GAS BURNER GAS BURNER GAS BURNER GAS BURNER
CONNECT GAS PIPING (LG_/LD_ UNITS)
Before connecting piping, ensure that installation satisfies
national and local standards.
Supply should be at the correct nominal pressure for the
gas type used (see table), and should remain within +/- 5
mbar of this pressure under all operating conditions. Pipes
should be sized to ensure that the pressure remains within
the correct operating range with all appliances operating.
Figure 55 shows complete bottom gas entry piping.
GAS PIPE CONNECTION OUTSIDE UNIT
Pressure tap
3,2 mm
Ground joint union
Manual main shut-off
valve
Gas piping support
NOTE :
LENNOX LINEA GAS FIRED
ROOFTOPS ARE NOT SUITABLE
FOR INTERNAL INSTALLATION.
THEY SHOULD BE INSTALLED
EXTERNAL TO THE BUILDING AND
IN CONJUNCTION WITH THE
GUIDELINES LAID OUT IN THIS
MANUAL.
GAS HEAT START UP
Gas Valve operation (Figure 56)
Gas appliance must only be started-up and commissioned
by suitably qualified personnel. The unit is equipped with a
fully automatic Spark ignitor system, there is no pilot. The
gas valve is fully automatic, and does not incorporate any
manual control.
During commissioning the manifold (gas valve outlet)
pressure must be checked at both high and low fire
conditions and adjusted as necessary (see above table).
Once commissioned, the burner operation is fully automatic.
In the event of failure to light, contact a suitably qualified
gas technician.
TO GAS VALVE
To Turn Off Gas To Unit
PRESSURE TEST GAS PIPING (LG_
Drip leg
UNITS)
Figure 55
When pressure testing gas lines, the gas valve must be
disconnected and isolated. Gas valves can be damaged if
subjected to more than 60mbar. See figure 57
If the test pressure is equal to or less than 60mbar, use the
main manual shut-off valve before pressure testing to isolate
the furnace fromthe gas supply system.
NOTE : Codes may require that manual main shut-off valve
and union (furnished by installer) be installed in gas line
external to unit. Union must be of the ground joint type.
After all connections have been made, check all piping
connections for gas leaks. Use a soap solution or
otherpreferred means. Do not use matches candles or other
sources of ignition to check for gas leaks.
NOTE : In case of emergency, shut down is required. Turn
off the main manual shut-off valve and disconnect main
power to unit. These devices should be properly labeled by
the installer.
GAS VALVE PRESSURE TAPPING LOCATIONS
1. Lower setpoint using KP02 maintenance controller.
2. Turn off all electrical power to unit if service is to be
performed.
3. Isolate gas supply external to unit.
PRESSURE TEST GAS VALVE
Manual main shut-off valve
Gas valve
IOM / Rooftop Smart and Linéa™ Range - Page 43
Inlet pressure tapping
point
Outlet pressure
tapping point
Figure 56
Cap
Figure 57