Start Up; Typical Operating Characteristics - Lennox Elite CBA27UHE Series Manual

IV-START‐UP - OPERATION
A-Preliminary and Seasonal Checks
1- Make sure the unit is installed in accordance with the
installation instructions.
2- Inspect electrical wiring, both field and factory installed for
loose connections. Tighten as required.
3- Check voltage at disconnect switch. Voltage must be with­
in range listed on the nameplate. If not, consult the power
company and have voltage condition corrected be­
fore starting unit.
4- Check to ensure that refrigerant lines are in good
condition and pipe insulation is intact.
5- Inspect condition of condensate drain pan and piping as­
sembly. Disassemble and clean seasonally.
B-Cooling Start‐Up
NOTE-The following is a generalized procedure and
does not apply to all thermostat control systems. Electronic
thermostat control systems may operate differently.
1- Set fan switch to AUTO or ON and move the system
selection switch to COOL. Adjust the thermostat to a set­
ting far enough below room temperature to bring on the
compressor. Compressor will start and cycle on demand
from the thermostat.
2- The refrigerant circuit is charged with HFC-410A re­
frigerant. See outdoor unit rating plate for correct
charge amount.
3- Refer to the correct outdoor unit service manual for more
information.
C-Heating Start‐Up
1- Set the fan switch to AUTO or ON and move the sys­
tem selection switch to HEAT. Adjust the thermostat
setting above room temperature.
2- The indoor blower immediately starts and the electric heat
will stage on based on sequencer timing.
D-Safety or Emergency Shutdown
Turn off unit power at circuit breaker.
E-Extended Period Shutdown
Turn off thermostat or set to "UNOCCUPIED" mode. Turn
off power to unit. All access panels and covers must be in
place and secured. The condensate assembly should be
clean and dry for extended period shutdown.
V-TYPICAL OPERATING CHARACTERISTICS
A-Blower Operation and Adjustment
NOTE- The following is a generalized procedure and
does not apply to all thermostat controls.
1- Blower operation is dependent on thermostat con­
trol system.
2- Generally, blower operation is set at thermostat sub­
base fan switch. With fan switch in ON position, blower
operates continuously. With fan switch in AUTO posi­
tion, blower cycles with demand.
3- In all cases, blower and entire unit will be off when the
system switch is in OFF position.
B-External Static Pressure
1- Measure tap locations as shown in figure 12.
STATIC PRESSURE TEST
SUPPLY
HORIZONTAL DIS-CHARGE LEFT POSITION
2- Punch a 1/4" (6mm) 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 re­
turn duct as above. For systems with non-ducted re­
turns, leave the other end of the manometer open to the
atmosphere.
3- With only the blower motor running and the evapora­
tor coil dry, observe the manometer reading. Adjust
blower motor speed to deliver the air desired accord­
ing to the installation requirements.
4- External static pressure drop must not exceed 0.8"
W.C.
5- Seal around the hole when the check is complete.
C-Blower Speed Taps
Motor Speed Taps
NOTE - Motor is programmed for a 45‐second delay off on
all speed taps except TAP #1 (continuous fan speed).
Tap Operation
1 Continuous or
low speed fan
(for 2-speed
heat pumps or
A/C units)
2 Low‐speed
operation on
high static
system
3 Cooling speed
setting
4 Heat pump
with electric
heat
5 High static
applications
Page 28
MANOMETER
RETURN
UNIT SHOWN IN
FIGURE 12
TABLE 1
Remarks
Continuous fan speed is energized
(24 volt input to "G") when either "G"
or "Y1" has a 24 volt signal (24 volt
input from "Y1" passes through the
room thermostat's "Fan Automatic
contacts" to the "G" terminal).
CFM set at 1/2 ton less than nominal
of unit (e.g. 3‐ton set at 1000 CFM).
CFM set at 400 cfm per nominal ton
at ARI minimum static allowed, as
follows: 1.5 to 2.0 ton - 0.10
2.5 to 3.5 ton - 0.15
4 to 5 ton - 0.20.
CFM set at 400 cfm per nominal ton
at .4 static. Energized when electric
heat element has a call for heat.
CFM set at 400 cfm per nominal ton
at .8 static.