Troubleshooting Problems With Major Components On Bc Controller; Pressure Sensor - Mitsubishi Electric HP120TNU-A Service Handbook

[8-9 Troubleshooting Problems with Major Components on BC Controller ]

8-9 Troubleshooting Problems with Major Components on BC
Controller
8-9-1

Pressure Sensor

Troubleshooting flow chart for pressure sensor
START
Check whether the pressure sensor or the
connectors of P1 and P3 are connected, properly
OK?
NO
Operating at the moment?
On the self-diagnosis monitor, measure
Outdoor high-pressure 63HS1
Outdoor low-pressure 63LS
BC controller pressure P1 (liquid side)
and P3 (intermediate part)
Check whether the result is
63HS1 P1 P3
OK?
All the compressors of the outdoor units to
which the BC controller is connected are stopped.
10 minutes or longer after
the operation stops?
Check P1 and P3 on the self-diagnosis
LED, and check that the detected
pressure is 0.098MPa [14psi] or more.
OK?
Check that the difference between each
detected pressure is 0.098MPa [14psi] or less.
OK?
Both the board and the pressure sensor are normal.
Check whether the refrigerant pipe and the
transmission line are connected correctly
between the outdoor unit and the BC controller.
OK?
30
- chapter 8
Note 1
Repair the fault.
YES
Note 2
63LS
Check whether the refrigerant pipe
NO
and the transmission line are
connected correctly between the indoor
unit and the BC controller.
YES
OK?
NO
NO
NO
Is Pd P1 P3 Ps?
YES
YES
Fix the relation between the
NO
refrigerant piping and the
transmission line.
YES
Fix the relation between
NO
the refrigerant piping
and the transmission line.
YES
Check whether the contact of the pressure
sensor connector in trouble is not faulty.
OK?
YES
NO
Remove the pressure sensor connector
from the board, and check the pressure.
Pressure 0MPa [0psi]
YES
Short-circuit between connecter pins #2 and #3
on the circuit board, and check the pressure.
6MPa [870psi] pressure
or more is displayed.
YES
Replace the failed sensor with a
normal sensor to see if the correct
pressure measurement is displayed.
OK?
YES
Replace the pressure sensor.
Note 3
NO
Note 4
Restore contact failure.
NO
NO
NO
Replace the board.
HWE18220_GB