Troubleshooting - Indoor Unit - Daikin DX20VC Service Instructions Manual

SERVICING
TROUBLESHOOTING-INDOOR UNIT FOR EEV APPLICABLE UNIT
AC C -OUT
(Accessory)
ACC -IN
(Accessory)
FUS E
X3A
E EV
COIL
Auxiliary Switch
The control is equipped with two Auxiliary Alarm terminals,
labeled TB4 and TB5, which are typically utilized in series
with a condensate switch but could also be used with com-
patible CO2 sensors or fire alarms.
TB5
ALARM
TB4
The auxiliary alarm switch must be normally closed and open
when the alarm occurs. For example, a normally closed con-
densate 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.
HIGH VOLTAGE
DISCONNECT ALL POWER BEFORE SERVICING OR
INSTALLING THIS UNIT. MULTIPLE POWER SOURC-
ES MAY BE PRESENT.
CAUSE PROPERTY DAMAGE, PERSONAL INJURY
OR DEATH.
A UXA LA R M
TB1
TB5 TB4 TB2
S E G 2
S E G 1
X15A
THE R MIST OR
P R ESS UR ESE NS OR
INDOOR UNIT CONTROL BOARD
SWITCH
WARNING
FAILURE TO DO SO MAY
X8A
R X LE D
CPU LED STATUS LED
7seg
7seg
X5A
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 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.).
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 accordance with the Electric Heating Airflow Table. Con-
figuring the dip switches and resetting power to the unit will
clear the error code.
C R 2 1
C C R R 2 2 1 1
X13A
X12A
Micro
P rocessor
45