Malfunction Of Low Pressure Sensor - Daikin E-Series Service Manual

SiENBE18-621

7.16 Malfunction of Low Pressure Sensor

JC
Remote Control
Display
Applicable
AII outdoor unit models
Models
Method of Malfunction is detected from pressure detected by low pressure sensor.
Malfunction
Detection
Malfunction
When the low pressure sensor is short circuit or open circuit.
Decision
Conditions
" Defect of low pressure sensor
Supposed
" Connection of high pressure sensor with wrong connection.
Causes
" Defect of outdoor unit PCB.
Troubleshooting
∗1: Voltage measurement point
∗2: Refer to "Pressure Sensor", pressure/voltage characteristics table on P357.
Troubleshooting
Be sure to turn off power switch before connect or disconnect connector,
Caution
or parts damage may be occurred.
The low
pressure sensor is
connected to X18A (blue)
of outdoor unit PC
board (A1P).
YES
The
relationship
between the *1
VL and low pressure is
normal (see *2) when voltage
is measured between X18A pins
(2) and (3) of outdoor unit
PC board (A1P)
(see *1).
NO
Outdoor unit PC board A1P
Microcomputer
A/D input
NO
YES
+5V
GND
*2 Measure voltage here.
Troubleshooting for Outdoor Unit
Connect low pressure sensor
property and restart system.
Replace outdoor unit PC board
(A1P).
Replace the low pressure sensor.
X18A
Red
Black
White
(V2809)
(V2808)
325