Typical Operating Characteristics; Maintenance - Lennox EL297DFV Series Unit Information

V-TYPICAL OPERATING CHARACTERISTICS
A-Blower Operation and Adjustment
1 - Blower operation is dependent on thermostat control
system.
2 - Generally, blower operation is set at thermostat
subbase fan switch. With fan switch in ON position,
blower operates continuously. With fan switch in
AUTO position, blower cycles with demand or runs
continuously while heating or cooling circuit cycles.
3 - Depending on the type of indoor thermostat, blower
and entire unit will be off when the system switch is
in OFF position.
B-Temperature Rise (FIGURE 54)
Temperature rise for EL297DFV units depends on unit in-
put, blower speed, blower horsepower and static pressure
as marked on the unit rating plate. The blower speed must
be set for unit operation within the range of "TEMP. RISE
°F" listed on the unit rating plate.
TEMPERATURE RISE
Supply Duct Temperature
Return Duct Temperature
Temperature Rise =
FIGURE 54
C-External Static Pressure
1 - Tap locations shown in FIGURE 55.
2 - Punch a 1/4" diameter hole in supply and return
air plenums. Insert manometer hose flush with
inside edge of hole or insulation. Seal around the
hose with permagum. Connect the zero end of the
manometer to the discharge (supply) side of the
system. On ducted systems, connect the other end
of manometer to the return duct as above.
3 - With only the blower motor running and the
evaporator coil dry, observe the manometer
reading. Adjust blower motor speed to deliver the
air desired according to the job requirements. For
heating speed (second stage heat speed) external
static pressure drop must not be more than 0.8"
_
Return
Temperatures
Supply
W.C. For cooling speed (second stage cool speed)
external static pressure drop must not be more than
1.0" W.C.
4 - Seal the hole when the check is complete.
EXTERNAL STATIC PRESSURE
Supply Duct Static
Return Duct Static +
Total Duct Static =
(dry coil)
VI-MAINTENANCE
ELECTRICAL SHOCK, FIRE,
OR EXPLOSION HAZARD.
Failure to follow safety warnings exactly could
result in dangerous operation, serious injury, death
or property damage.
Improper servicing could result in dangerous
operation, serious injury, death, or property damage.
Before servicing, disconnect all electrical power to
furnace.
When servicing controls, label all wires prior
to disconnecting. Take care to reconnect wires
correctly. Verify proper operation after servicing.
At the beginning of each heating season, system should
be checked as follows by a qualified service technician:
Blower
Check the blower wheel for debris and clean if necessary.
The blower motors are prelubricated for extended bearing
life. No further lubrication is needed.
The blower access panel must be securely in place
when the blower and burners are operating. Gas
fumes, which could contain carbon monoxide, can
be drawn into living space resulting in personal
injury or death.
Page 64
Return
+
−
Low "-"
or
High "+"
Supply
FIGURE 55
WARNING
WARNING