SiENBE28-901
Troubleshooting
Air Cooled Refrigeration Condensing Unit
89
Troubleshooting
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Check for the points shown below.
(1)Is the stop valve open?
(2)Is the HPS connector properly connected to the
main PCB?
(3)Does the high pressure switch have continuity?
Are the three
points above
OK?
(1)Mount a pressure gauge on the high pressure
service port.
(2)Reset the operation with power breaker or
operation switch and then restart the operation.
Does the stop due to
malfunction (
E3
)
recur?
Is the HPS operating
value normal (i.e.,
3.8MPa)?
Are the characteristics of
the high pressure sensor
normal? (See
∗
1.)
Service Checker
Connect the service checker to compare the “high pressure” value and the
actual measurement value by pressure sensor (Refer to
∗
1) by using the
service checker.
Check if the “high
pressure” value and the
actual measurement
value by pressure sensor
are the same.
· The high pressure sensor is normal, and the pressure detected with the PCB is also normal.
· The high pressure has really become high.
Referring to information on P134, remove the causes by
which the high pressure has become high.
CHECK 5
NO
YES
YES
NO
NO
YES
NO
YES
NO
YES
Rectify the defective points, if
any.
Replace the HPS.
Replace the high pressure sensor.
Replace the main PCB (A1P).
∗
1:Make a comparison between the voltage of the pressure sensor and that read by the
pressure gauge.
∗
2:Make measurement of voltage of the pressure sensor.
+5V
Connector for high
pressure sensor (Red)
(4)
(3)
(2)
(1)
Red
Black
White
High
pressure
sensor
Micro-controller
A/D input
Make measurement of DC
voltage between these wires.