SERVICING
38
Auxiliary Alarm Switch
The control is equipped with two Auxiliary Alarm terminals,
labeled CAS, which are typically utilized in series with a con-
densate switch but could also be used with compatible CO
2
sensors or fire alarms.
CAS
SWITCH
This feature can be activated or deactivated through the
thermostat user menus. The auxiliary alarm switch must be
normally closed and open when the alarm occurs. For ex-
ample, a normally closed condensate switch will open when
the base pan’s water level reaches a particular level. The
control will respond by turning off the blower motor and out
-
door unit and displaying the proper fault codes. If the switch
is later detected closed for 30 seconds, normal operation
resumes and the error message is removed. The error will
be maintained in the equipment’s fault history. See FIGURE
15 on the following page for the connection location.
Circulator Blower
This air handler is equipped with a variable speed circulator
blower. This blower provides several automatically-adjusted
blower speeds. The Specification Sheet applicable to your
model provides an airflow table, showing the relationship
between airflow (CFM) and external static pressure (E.S.P.).
The electric heat dip switch default position is set to the OFF,
OFF, OFF position and should be adjusted by the installer
to match the installation requirements for the correct electric
heating CFM.
Using the Electric Heat Airflow table below, set dip switches
9, 10, and 11 for the installed heater kit. Verify selected CFM
by counting the green CFM LED blinks. The green CFM
LED blinks once for each 100 CFM of airflow.
If an electric heater kit has not been installed, set dip switch-
es 9, 10, and 11 to any appropriate heater kit setting.
(See next page table for valid settings)
During the cooling operation, the outdoor unit will determine
the indoor airflow.
COM
TH
TR
DE
CAS
HUM
O
R
2
1
C
2
1
ST4
ST3
ST2
ST1
3A
C
Y2
24VAC
FUSE
W1
W2
R
C
G
W1
W2
Y1
3
2
Dip Switches
Green CFM LED
Seven Segment
LED
Auxiliary
Alarms
Communic
a�n
g Board