Activation Of Low Pressure Sensor - Daikin REYQ-XA Service Manual

Troubleshooting by Error Code

3.34 Activation of Low Pressure Sensor

E4
Error Code
Applicable
All outdoor unit models
Models
Method of Error
Make judgment of pressure detected by the low pressure sensor with the outdoor unit main PCB.
Detection
Error Decision When low pressure caused a drop while the compressor is in operation:
Conditions
Supposed
Causes
Troubleshooting
∗1. Make a comparison between voltage measured by the pressure sensor and that read by the
Note:
CHECK 2
CHECK 12
295
Operating pressure: 0.07 MPa (10.2 psi)
Abnormal drop in low pressure
Defective low pressure sensor
Defective outdoor unit main PCB
The stop valve is not opened
Be sure to turn off the power switch before connecting or disconnecting
Caution
connectors, or parts may be damaged.
Is the stop
valve open?
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.
Are the
characteristics
of the low pressure
sensor normal?
(∗1)
YES
Service Checker CHECK 12
Compare the low pressure value checked with the Service Checker and the actual value
measured by pressure sensor (∗1).
Check if
the low
pressure value
and the actual value
measured by
pressure sensor
are the same.
YES
- The low pressure sensor is normal, and the outdoor unit main PCB is also normal.
- The low pressure has really become low.
: Eliminate factors that cause the low pressure to decrease.
CHECK 2
pressure gauge.
(The pressure sensor makes measurement of voltage at its connector block to convert it to
pressure. CHECK 12 )
Refer to page 375.
Refer to page 388.
NO
Open the stop valve.
NO
Replace the low pressure sensor
(S1NPL).
NO
Replace the outdoor unit main
PCB (A1P).
SiUS371901E
Service Diagnosis