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5. Troubleshooting method of main parts of BC controller
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6MPa pressure or
more is displayed.
OK?
OK?
OK?
OK?
Pressure
0MPa
10 minutes or longer after
the operation stops?
OK?
Start
Fix the fault.
Restore contact
failure.
Replace
the board.
Replace the pressure sensor.
OK?
OK?
Both the board and the pressure sensor are normal.
OK?
Is Pd P1
P3 Ps?
Note3
6MPa pressure or
more is displayed.
Note4
Note1
Note2
Operating at
the moment?
Fix the relation be-
tween the refriger-
ant piping and the
transmission line.
Check whether the connection relation between
the refrigerant piping, between the outdoor unit
arrow and the BC controller, and the trans-
mission line corresponds.
Check that the difference between each detect-
ed pressure is 0.098MPa or less.
Check whether the connector of the ap-
plied pressure sensor is not faulty.
Remove the pressure sensor connector
from the board, and check the pressure.
Short-circuit the connector pins between No.2
and 3 on the board, and check the pressure.
Replace the pressure sensor, which de-
tects less than 6MPa pressure, with the
pressure sensor, which detects 6MPa or
more pressure, check the pressure, and
check whether the detected pressure is
displayed normally.
Stop the applied BC controller system.
(Compressor OFF)
Check P1 and P3 with the self-diagnosis moni-
tor, and check that the detection pressure is
0.098MPa or more.
Check whether the pressure sensor or the con-
nectors of P1 and P3 are not disconnected, not
loose, or not connected wrongly.
With the self-diagnosis monitor, measure
· Outdoor high-pressure 63HS
· Outdoor low-pressure 63LS
· BC controller pressure P1 (liquid side) and
P3 (intermediate part)
Check whether the result is 63HS P1 P3 63LS.
Check whether the
connection relation
between the refriger-
ant piping, between
the outdoor unit ar-
row and the BC
controller, and the
transmission line
corresponds.
Fix the relation between the
refrigerant piping and the
transmission line.
(1) Pressure sensor
Troubleshooting flow chart for pressure sensor