Blower Compartment - Lennox G32V Series Service Literature

C−Blower Compartment (Figure 17)
Located inside the blower compartment are the variable
speed blower motor (B3), coil choke (L13), and the sec-
ondary limit switches [(1)S21 and (2)S21]. To access the blow-
er compartment follow the steps outlined below:
1. Blower Motor (B3)
G32V units use a three-phase, electronically controlled D.C.
brushless motor (controller converts single phase a.c. to three
phase D.C.), with a permanent-magnet-type rotor (figure 18).
Because this motor has a permanent magnet rotor it does not
need brushes like conventional D.C. motors. Internal compo-
nents are shown in figure 19. The stator windings are split into
three poles which are electrically connected to the controller.
This arrangement allows motor windings to turn on and off
in sequence by the controller.
SUPPLY AIR BLOWER
AND SECONDARY LIMITS
COIL
CHOKE
(L13)
To Remove Blower From Unit: Remove Bolts and
Wiring Jackplugs. Then Slide Out Front of Unit.
FIGURE 17
To Remove Blower:
1. Turn off line voltage power. Unplug J69
from P69 located on blower deck.
2. Disconnect thermostat wiring connec-
tions at the terminal strip.
3. Disconnect J58/P58 and located on blow-
er deck.
4. Disconnect J43/P43 and J49/P49 from
blower motor.
5. Disconnect wires from power choke.
6. Remove screw from control panel brack-
et at the blower.
7. Loosen screws (2) and remove control
box assembly from unit. Holes are slotted
so screws do not need to be removed.
8. Remove screws (2) and remove blower
from unit.
BLOWER
BLOWER
WHEEL
MOTOR (B6)
1
8
G32V BLOWER MOTOR B3
SHAFT
MOTOR
CONTROLLER
G32V BLOWER MOTOR COMPONENTS
A solid-state controller is permanently attached to the
motor. The controller is primarily an A.C. to D.C. convert-
er. Converted D.C. power is used to drive the motor. The
controller contains a microprocessor which monitors
varying conditions inside the motor (such as motor work-
load).
The controller uses sensing devices to sense what position
the rotor is in at any given time. By sensing the position of the
rotor and then switching the motor windings on and off in se-
quence, the rotor shaft turns the blower.
G32V series blower motor ratings are listed in table 29.
All G32V blower motors use single phase power. An ex-
ternal run capacitor is not used. The motor uses perma-
nently lubricated ball-type bearings.
7
7
2
5
FIGURE 20
Page 30
J48
J49
FIGURE 18
STATOR
(WINDINGS)
BEARING
OUTPUT
SHAFT
ROTOR
FIGURE 19
3 3
4 4
6