Iv-Start Up - Operation - Lennox LGT Series Unit Information

IV-START-UP - OPERATION
Refer to start-up directions and to the unit wiring diagram
when servicing. See unit nameplate for minimum circuit
ampacity and maximum fuse size.
A-Preliminary and Seasonal Checks
1 - Make sure the unit is installed in accordance with
the installation instructions and applicable codes.
2 - Inspect all electrical wiring, both field and factory
installed for loose connections. Tighten as required.
Refer to unit diagram located on inside of unit
control box cover.
3 - Check to ensure that refrigerant lines are in good
condition and do not rub against the cabinet or
other refrigerant lines.
4 - Check voltage. Voltage must be within the range
listed on the nameplate. If not, consult power
company and have the voltage corrected before
starting the unit.
5 - Recheck voltage and amp draw with unit running. If
voltage is not within range listed on unit nameplate,
stop unit and consult power company. Refer to unit
nameplate for maximum rated load amps.
6 - Inspect and adjust blower belt (see section on
Blower Compartment - Blower Belt Adjustment).
B-Cooling Start-up See figure 23
NOTE-Crankcase heaters must be energized 24 hours
before attempting to start compressor. Set thermostat so
that there is no demand to prevent compressor from cy-
cling. Apply power to unit.
REFRIGERANT STAGES -
All-Aluminum Coil
CONDENSER COIL
STAGE 1
EVAPORATOR
COIL STAGE 2
2
1
FIGURE 23
(BOTH FANS ARE ENERGIZED
WITH A Y1 DEMAND)
B4
B5
CONDENSER COIL
STAGE 2
EVAPORATOR
COIL STAGE 1
1 - Initiate first, second or third stage cooling demands
according to instructions provided with thermostat.
2 - With 2-stage cooling thermostat, the first-stage
thermostat demand will energize compressor 1
Full Load. Second-stage thermostat demand will
energize compressor 2.
With 3-stage cooling thermostat, the first-stage ther-
mostat demand will energize compressor 1 Part Load.
Second-stage thermostat demand will energize com-
pressor 2.
Third-stage thermostat demand will energize compres-
sor 1 Full Load and Compressor 2
3 - Units contain two refrigerant circuits or stages.
4 - Each refrigerant circuit is separately charged with
refrigerant. See unit rating plate for correct amount
of charge.
C-Heating Start-up
FOR YOUR SAFETY READ BEFORE LIGHTING
Danger of explosion. Can cause injury
or product or property damage. If
overheating occurs or if gas supply
fails to shut off, shut off the manual gas
valve to the appliance before shutting off
electrical supply.
Electric shock hazard. Can cause injury
or death. Do not use this unit if any part
has been under water. Immediately call a
qualified service technician to inspect the
unit and to replace any part of the control
system and any gas control which has
been under water.
BEFORE LIGHTING smell all around the appliance area
for gas. Be sure to smell next to the floor because some
gas is heavier than air and will settle on the floor.
Use only your hand to push in or turn the gas control knob.
Never use tools. If the knob will not push in or turn by
hand, do not try to repair it, call a qualified service tech-
nician. Force or attempted repair may result in a fire or
explosion.
Units equipped with a Hot Gas Reheat system MUST
be charged in standard cooling mode.
In case of a safety shutdown, move thermostat switch to
OFF and return the thermostat switch to HEAT to reset
ignition control.
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WARNING
WARNING
IMPORTANT