Daikin RXYQ-TA Series, Service Manual

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Troubleshooting by Error Code SiUS341615E
217 Service Diagnosis
3.30 Actuation of Low Pressure Sensor
Error Code
E4
Applicable
Models
All outdoor unit models
Method of Error
Detection
Make judgement of pressure detected by the low pressure sensor with the outdoor unit main PCB.
Error Decision
Conditions
When low pressure caused a drop while the compressor is in operation:
„
Operating pressure: 0.07 MPa (10.2 psi)
Supposed
Causes
„
Abnormally drop in low pressure
„
Defective low pressure sensor
„
Defective outdoor unit main PCB
„
The stop valve is not opened
Troubleshooting
YES
NO
NO
YES
Are the
characteristics
of the low pressure
sensor normal?
(
∗
1)
NO
YES
(1)Mount a pressure gauge on the low pressure
service port.
(2)Reset the operation using the remote
controller, and then restart the operation.
Is the stop
valve open?
- The low pressure sensor is normal, and pressure detection with the
outdoor unit main PCB is also normal.
- The low pressure has really become low.
Replace the outdoor unit main
PCB (A1P).
Replace the low pressure sensor
(S1NPL).
Open the stop valve.
CHECK 2
CHECK 12
Check if
the low
pressure value
and the actual value
measured by
pressure sensor
are the
same.
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
: Eliminate factors that cause the low pressure to decrease.
Compare the low pressure value checked with the Service Checker and the
actual value measured by pressure sensor (
∗
1).
Service Checker