Lennox XC21 Installation Instructions Manual page 45

A177 FAN MOTOR CONTROL
PULSE−WIDTH MODULATION (PWM)
CONTROL PANEL
A175 MAIN
CONTROL
VERIFY DC VOLTAGE OUTPUT USING FAN PWM OUT AND
COM TERMINALS. SEE TABLE 16 FOR OPTIMAL DC
VOLTAGE BASED ON CFM PROFILE USED.
GREEN
RED
RED
YELLOW
YELLOW
YELLOW
Figure 24. A177 Fan Control, Wiring, Jumper Settings, Testing and LED Location
J2
COM
FAN PWM OUT
S4 HIGH PRESSURE SWITCH
A175 MAIN CONTROL
Page 45
CFM Profile Pin Select
JUMPER
JUMPER
OFF
ON
J2
YELLOW
BLUE
BLACK
YELLOW
YELLOW
A177 FAN
MOTOR
SEE TABLE 16 FOR CFM PROFILE
CONTROL
SELECTION OPTIONS.
LED
GREEN
RED
RED
B4 FAN
MOTOR
BLACK
BROWN
XC21 SERIES