E4" Outdoor Unit: Actuation Of Low Pressure Switch - Daikin R-410A Service Manual

Troubleshooting by Indication on the Remote Controller

4.16 "E4" Outdoor Unit: Actuation of Low Pressure Switch

E4
Remote
Controller
Display
Applicable
AII outdoor unit models
Models
Method of
Malfunction
Detection
Malfunction
Error is generated when the low pressure is dropped under specific pressure.
Decision
Conditions
! Abnormal drop of low pressure
Supposed
! Defect of low pressure sensor
Causes
! Defect of outdoor unit PC board
! Stop valve is not opened.
Troubleshooting
∗1: Voltage measurement point
∗2: Refer to pressure sensor, pressure / voltage characteristics table on P200.
128
Be sure to turn off power switch before connect or disconnect connector,
Caution
or parts damage may be occurred.
NO
Is stop valve opened?
YES
Is the malfunction YES
due to abnormal drop of low
pressure?
NO
Measure
the voltage (VL)
of X45A pin No.
(2) - (3) of outdoor PC board
YES
(A1P).∗1 Is the
relationship between
low voltage and VL
normal?
∗2
NO
Outdoor unit PC board A1P
Microcomputer
A/D input
∗2 Measure voltage (DC) within this space.
+5V
GND
SiBE39-402A
Open stop valve.
Out of gas, refrigerant system
clogging, wiring and piping wrong
connection, stop valve closed,
electronic expantion valve fully
close malfunction.
Replace the low pressure sensor.
Replace outdoor unit PC board A1P.
X45A
(blue)
Red
Black
White
Troubleshooting
(V2791)