Unit Components; Blower Assembly - Lennox CB26UH Unit Information

II−UNIT COMPONENTS
A−Control Box
The CB26UH and CBX26UH control box is located above
the blower section shown in figure 1. Line voltage and elec-
tric heat connections are made in the control box. Optional
electric heat fits through an opening located in the center of
the control box. When electric heat is not used, cover plates
cover the opening. The electric heat control arrangement is
detailed in the electric heat section of this manual.
1−Transformer
All CB26UH and CBX26UH series units use a single line
voltage to 24VAC transformer mounted in the control
box. The transformer supplies power to the control cir-
cuits in the indoor and outdoor unit. Transformers are
rated at 40VA. 208/240VAC single phase transformers use
two primary voltage taps as shown in figure 2.
208 / 240 VOLT TRANSFORMER
PRIMARY
ORANGE
240 VOLTS
RED
208 VOLTS
BLACK
FIGURE 2
2−Blower Relay
All CB26UH and CBX26UH units use a DPST relay to en-
ergize the blower motor. The relay coil is energized by
blower demand from indoor thermostat. When the coil is
energized, a set of N.O. contacts closes to energize the blower
motor on cooling speed. When de−energized, a set of N.C.
contacts allows the electric heat relay to energize the blower on
heating speed (refer to unit wiring diagram).
3−Time Delay Relay
The blower time delay is a 24 volt N.O. relay wired to the
blower relay. See unit diagram. The delay is between 10
and 60 seconds and delays the blower on and off time in the
cooling cycle.
SECONDARY
BLUE
YELLOW
Page 5

BLOWER ASSEMBLY

FIGURE 3
B−Blower Motor (B3)
CB26UH and CBX26UH units use single phase direct drive
blower motors with a run capacitor. Figure 3 shows the
parts arrangement. All motors have two speed taps. Typi-
cally, the high speed tap is energized during normal opera-
tion.
All units are factory wired for the high blower speed for heat
pump and cooling applications with or without electric heat. No
field wiring is required. The wiring diagrams show factory set
blower speeds.
1−Blower Motor Capacitor
All CB26UH and CBX26UH series units use single phase di-
rect drive motors with a run capacitor. The run capacitor is
mounted on the blower housing. See figure 3. Capacitor rat-
ings are shown on side of capacitor and indoor blower motor
nameplate.
C−Coil
CB26UH and CBX26UH units have dual slab coils ar-
ranged in an A" configuration. Each coil has two or three
rows of copper tubes fitted with ripple−edged aluminum
fins. An expansion valve, feeds multiple parallel circuits through
the coils. The coil is designed to easily slide out of the unit cabi-
net.
D−Plastic Drain Pans
Drain pans are provided and installed on the CB26UH and
CBX26UH, The drain pans are made from fiberglass filled
plastic.