Table of Contents
Advertisement
FURNACE CONTROL BOARD AND BLOWER CONTROL
32. INDOOR BLOWER OPERATION
All models have multiple speed direct drive blower
motors. If supply and return ducts are connected to the
unit, the ducts must be of adequate size. Refer to the
appropriate blower tables. See Tables 10, 11, 12, 13,
14 and 15 for maximum static pressures acceptable.
Note the minimum CFM for cooling operation.
If voltage and duct design permit, (see blower tables)
single speed operation can be achieved as follows:
230 VOLT BLOWER MOTOR SPEED CHANGE
1. Disconnect main power supply to unit.
2. Remove and tape off the unwanted indoor motor
speed tap from the heat or cool terminal on the
furnace control board.
3. Next install a jumper wire with multiplier between
heat and cool terminal and attach desired blower
motor speed to other side of multiplier.
4. Energize the system in cooling and heating modes
and check for proper blower operation.
FIGURE 18
460 VOLT BLOWER MOTOR SPEED CHANGE
Field changeover from the factory blower motor speed
settings can require change several different motor
leads, the addition or deletion of a wire.
Refer to blower motor wiring options as shown below
for the correct wiring of the blower motor for the
application involved.
S
p
e
e
d
L
o
w
M
e
. d
L
o
M
e
. d
M
e
. d
H
g i
H
g i
h
FURNACE CONTROL
BOARD
ATTACH JUMPER WIRE
HERE FOR SINGLE
SPEED OPERATION
MIS-1482
TABLE 9
MOTOR SPEED TAPS
s
3
S
p
e
e
d
M
t o
r o
R
e
d
w
N
A
B
u l
e
h
N
A
B
a l
k c
Manual 2100-376
Page 36
4
S
p
e
e
d
M
t o
r o
R
e
d
P
u
p r
e l
N
A
B
u l
e
B
a l
k c
Advertisement
Table of Contents
