Energy Recovery Wheels - Lennox LGH480 Installation Instructions Manual

Optional Energy Recovery Wheel
Unit may contain an optional energy recovery wheel. The
ERW is located in the outdoor air entering and exhaust air
streams. In the heating mode, the wheel rotates to transfer
heat from the exhaust air stream to the outdoor air intake air
stream. In the cooling mode the process reverses. See
figure 55.
The ERW motor (B28) is energized when outdoor air is
above 65°F (S125) or below 40°F (S23). Refer to wiring
diagram on unit panels.
EXHAUST
AIR
507232-04 7/2017
ENERGY RECOVERY WHEEL
OUTDOOR
AIR
DIVISION
PANEL
Note - When the outdoor air temperature is between 65°F
and 40°F, DL43 will energize the ERW for one minute every
ten minutes to clean the wheel.
By-pass dampers will close as outdoor air dampers close or
move to minimum position.
ERW should operate on unit start-up unless the outdoor
temperature is between 40°F and 65°F. To check ERW
operation when outdoor air temperature is between 40°F
and 65°F, install a jumper between S125 thermostat
terminal "R" and K94 relay coil terminal "A".
ERW WHEEL
BY-PASS DAMPERS
FIGURE 55
Page 59
EXHAUST
AIR
ERW MOTOR