Vertical; Installation Of Control Wiring; Installation Of Discharge Air Sensor - LG GEN2 Series Installation And Operation Manual

Installation of Two Pipe Venting – Vertical
Refer to the diagram for venting vertical two pipe
systems. The combustion air pipe must terminate at
least 12 inches above the roof. This clearance may
need to be increased to accommodate for snow
accumulation. The exhaust must terminate at least
12 inches above and 12 inches horizontally from the
combustion air inlet.
A = 12 inch minimum, but size
according to expected snow depth B
= 12 inch minimum
C = 12 inch minimum
D = 12 inch minimum
Roof Line
Vent Connection Diameter
Vent terminals must
be used. The vent kit
includes two terminals
per furnace. Construct
the vent system as
shown in the drawings
and refer to the table
for the correct vent connection diameters.
Vent Length
Refer to table for minimum and maximum vent lengths.
The minimum vent length is 10 feet and the maximum
vent length is 70 feet. The total equivalent vent length
must include elbows. The
equivalent length of a
4 inch elbow is 6 feet and
the equivalent length of a
6 inch elbow is 10 feet.
Install Exhaust Pipe
Run an exhaust pipe from the unit's combustion exhaust
through the roof to the outdoors. The exhaust pipe must
terminate at least 24 inches above the outside surface of
the roof. This clearance may need to be increased to
accommodate snow accumulation. Attach the exhaust
vent terminal to the end of the exhaust pipe.
Exhaust Vent
Terminal
Combustion
Air Inlet
Terminal
Tee with
drip leg and
clean-out cap
Vertical Two Pipe Venting
Vent Connection Diameter
Furnace Size Exhaust Combustion
(MBH) (inches) (inches)
75-175 4
200-400 6
Vertical Two Pipe Venting
Vent Length
Vent Minimum Maximum
Length (feet) (feet)

Vertical

10
Install Combustion Air Pipe
Run a combustion air pipe from the unit's combustion
air intake through the roof to the outdoors. The
combustion air pipe must terminate at least 12 inches
horizontally and vertically from the combustion exhaust
pipe and at least 12 inches from the exterior surface of
the roof. These clearances may need to be increased
to accommodate for expected snow accumulation.
Attach the combustion air terminal to the end of the
combustion air pipe.
Seal Roof Penetration
Using an appropriate method, seal the roof openings
around the vent pipes.

Installation of Control Wiring

Disconnect power supply before making any wiring
connections to prevent electrical shock and equipment
damage.
All appliances must be wired strictly in accordance with
the wiring diagram furnished with the unit. Any wiring
different from the diagram could result in a hazard to
persons and property.
Any original factory wiring that requires replacement
must be replaced with wiring material having a
temperature rating of at least 105° C.
1. Installation of wiring must conform with local building
codes. In the absence of local building codes,
installation must conform to the National Electrical
Code and ANSI/NFPA 70 - Latest Edition. Unit must
be electrically grounded in conformance with this
code. In Canada, wiring must comply with CSA
C22.1, Canadian Electrical Code.
4
2. All furnaces are provided with a wiring diagram
6
located on the inside of the access panel or door to
the unit's furnace. Refer to this diagram for all wiring
connections.

Installation of Discharge Air Sensor

Every furnace has a Discharge Air Sensor included.
It is typically attached to the terminal strip on the
furnace control center. If the ventilating unit has a
microprocessor controller, the discharge air sensor will
be connected to the microprocessor controller. See the
70
unit-specific wiring diagram. Install sensor in the supply
air duct, as far downstream as possible for accurate
temperature measurement. Additional wire may be
added to the sensor as necessary.