Page 29
Table 2 shows the recommended factory blower speed tap
selections for CBA27UHE series units.
These settings are for nominal tonnage match-ups with the
CBA27UHE units. When matched with other sizes, it is rec
ommended that the CFM be adjusted to approximately 400
CFM per ton.
To change blower motor speed tap remove the speed tap
from Y2 on the terminal strip and insert the desired speed
tap. See blower data on pages 4 and 5 for the desired CFM
setting
TABLE 2
Recommended Blower Speed Tap Selection
Operation
CBA27UHE
Outdoor unit
Tap
Cooling
ALL
MODELS
Condensing unit
3
Heat pump
3
Heating*
Condensing unit with elec
tric heat only
4
Heat pump with electric heat
4
* Minimum setting for heat
NOTE -
Motor is programmed for a 45‐second delay off on
all speed taps except TAP #1 (continuous fan speed).
VI-MAINTENANCE
NOTICE !
Failure to follow instructions will cause damage to
the unit.
This unit is equipped with an aluminum coil. Alu
minum coils may be damaged by exposure to solu
tions with a pH below 5 or above 9. The aluminum coil
should be cleaned using potable water at a moderate
pressure (less than 50psi). If the coil cannot be
cleaned using water alone, Lennox recommends use
of a coil cleaner with a pH in the range of 5 to 9. The
coil must be rinsed thoroughly after cleaning.
In coastal areas, the coil should be cleaned with
potable water several times per year to avoid corro
sive buildup (salt).
WARNING
Disconnect power before performing any
maintenance.
At the beginning of each heating / cooling season, the sys
tem should be checked as follows:
A-Filters
IMPORTANT
Filter access panel must be in place during unit op
eration. Excessive warm air entering the unit may re
sult in water blow-off problems.
Filters may be duct-mounted or installed in the cabinet. A
filter is installed at the factory. Note that filter access door
fits over access panel. Air will leak if the access panel is
placed over the filter door.
Filters should be inspected monthly and must be cleaned or
replaced when dirty to assure proper air handler operation.
Units are equipped with standard throw-away type filters
which should be replaced when dirty.
To remove filter, loosen the thumbscrews holding the filter
panel in place. Slide filter out of the guides on either side of
cabinet, insert new filter and replace panel.
TABLE 3
CBA27UHE Model
Filter Size - In. (mm)
-018, -024, -030, -036
20 x 20 (508 x 508)
-042, -048, -060
20 x 24 (508 x 610)
B-Supply Air Blower
1‐ Check and clean blower wheel.
2‐ Motors are pre-lubricated for extended life; no further lu
brication is required.
C-Electrical
1‐ Check all wiring for loose connections.
2‐ Check circuit breaker located in unit control box.
3‐ Check for correct voltage at unit (unit operating).
4‐ Check amp‐draw on blower motor.
5‐ Check to see that heat (if applicable) is operating.
D-CONSTANT TORQUE SPEED BLOWER
MOTOR (ECM) (B3)
Blower Motor (B3)
To Remove Blower From Unit: Remove wiring jack plug and
three screws and slide blower out.
TYPICAL BLOWER MOTOR
(B3) REMOVAL
FIGURE 13
