Service manual

ESIE05-03 Error Codes: Outdoor Units
Part 3 – Troubleshooting 3–61
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3.4 Actuation of Low Pressure Sensor: RZQ71B8V3B (E4)
Remote Controller
Display
E4
Method of
Malfunction
Detection
Actual value of the low pressure is continuously measured using the low pressure sensor.
Malfunction
Decision
Conditions
Error is generated when the low pressure is dropped under specific pressure.
Supposed Causes
P Abnormal drop of low pressure (Lower than 0.15MPa)
P Defect of low pressure sensor
P Defect of outdoor unit PC board
P Stop valve is not opened.
Troubleshooting
*1: Voltage measurement point
Low
pressure at stop
due to malfunction is
0.15 MPa.
Measure
the voltage (VL)
of X64A pin No. (2) - (3)
of outdoor PC board (A1P).∗1
Is the relationship between
low voltage and VL
normal?
Is stop
valve opened?
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.
NO
NO
YES
YES
Open stop valve.
NO
YES
ESIE05-03.book Page 61 Wednesday, April 6, 2005 4:09 PM