Barometric Relief Dampers; Outdoor Air Dampers; Outdoor Air Hoods - Lennox LGH480 Installation Instructions Manual

1- Connect field-provided 1/4" tubing to the (+) port on the
transducer. Route tubing through unit return air opening
to a return air grille in the duct work.
2- Locate the outdoor air kit shipped in a box in the unit
filter section. Install outdoor air kit on the top of the unit
in location shown in figure 44. Use manufacturer's
instructions.
Note - Outdoor kit reduces fluctuations in reference reading
due to wind gusts.
3- Locate the tubing provided with the outdoor air kit.
Route the tubing from the outdoor kit through the hole
under the intake hood to A34 as shown in figure 44.
Connect tubing to the (-) port on the transducer. Coil
and secure excess tubing - do not cut.
ROUTE TUBING TO OUTDOOR (REFERENCE) AIR
INSTALL OUTDOOR
AIR KIT ON UNIT
ROUTE REFERENCE
TUBING THROUGH
HOLE TO (A34)
FIGURE 44
Power Exhaust VFD By-Pass Plug (Optional)
The power exhaust VFD may be by-passed using jack/plug
connections. Locate J/P211 connectors in control box area
under the relays. Disconnect J211 from P211 and connect
J215 to P211. See figure 45. Exhaust blower will operate at
maximum speed.
POWER EXHAUST VFD BY-PASS CONNECTOR
CONNECTORS USED
FOR EXHAUST VFD
OPERATION
J211
P211
FIGURE 45
507232-04 7/2017
TO A34
TRANSDUCER
CONNECTORS USED TO BY-
PASS VFD AND OPERATE
EXHAUST BLOWER AT
MAXIMUM SPEED
J215
P211
Optional Outdoor Air Dampers
Unit may contain optional outdoor air dampers which
provide fresh outdoor air. Dampers are either motorized or
manually set. Motorized dampers are controlled by the Unit
Controller. Manual dampers are adjusted and remain in the
same position. Set the damper minimum position in the
same manner as the economizer.
Optional Barometric Relief Dampers
Unit may contain optional barometric relief dampers in the
unit return air compartment to relieve excess building
pressure. Remove shipping strap and replace screws
before operation. No adjustments are necessary.
Optional Outdoor Air / Barometric Relief
Hoods
Hoods are shipped in the filter section.
1-Remove the shipping covers over the outdoor air
openings.
2-Assemble hoods as shown in figure 46.
3-Secure hoods to unit as shown in figure 47. Outdoor air
filters are factory-installed in unit.
4-When installing outdoor air hoods, secure hinged panel
on screen to unit . See figure 48. Install two screws to
hold screen in place.
Page 51
ASSEMBLE HOOD
FIGURE 46