51
SERVICING
AUXILIARY A LARM S WITCH
The control is equipped with two Auxiliary Alarm terminals, la-
beled TB4 and TB5, which are typically utilized in series with a
condensate switch but could also be used with compatible CO
2
sensors or fire alarms.
TB5
SWITCH
ALARM
TB4
The auxiliary alarm switch must be normally closed and open
when the alarm occurs. For example, a normally closed conden-
sate 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 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 switch is closed as part of the
default factory setting. The error will be maintained in the
equipment's fault history.
CIRCULATOR B LOWER
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.).
NOTE: Upon start up in communicating mode the circuit board
may display an “Ed” error. This is an indication that the dip
switches on the control board need to be configured in accor-
dance with the Electric Heating Airflow Table. Configuring the dip
switches and resetting power to the unit will clear the error code.
TROUBLESHOOTING-INDOOR UNIT
HIGH VOLTAGE !
D
ISCONNECT
ALL
POWER
BEFORE
SERVICING
.
M
ULTIPLE
POWER
SOURCES
MAY
BE
PRESENT
. F
AILURE
TO
DO
SO
MAY
CAUSE
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
.
WARNING
X3A
X15A
X5A
SEG2
SEG1
X 12A
X13A
X8A
INDOOR UNIT PCB
THERMISTOR
Micro
Processor
PRESS UR E SE NSOR
EEV
COIL
FUS E
TB4
TB1
TB5
TB 2
C
R
2
1
S1 S2 S3 S 4
Heater Kit
Output
ECM M otor
ON
OFF
DS1
DS2
DS3
D
S
4
D
S
5
F
U
S
E
F
1
U
X
1
A
SHARE DAT A
S5 S6 S7 S 8
S9 S1 0 S11 S12
S13 S1 4 S15 S 16
S17 S18 S19 S20
S21 S22
F
2
U
T
B
6
T
B
8
T
B
7
T
B
1
0
T
B
3
D
S
6
O
N
O
F
F
7seg
7seg
X
2
A
X
7
A
C
R
2
1
AU X AL A
C
R
2
1
ACC-OUT
ACC-IN
(Accessory)
(Ac cessory)
B
S
2
B
S
1
F
A
U
L
T
R
E
C
A
L
L
L
E
A
R
N
RX LED
CPU LED
STATUS LED
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