Troubleshooting Problems With Major Components On Hydro Unit; Pressure Sensor - Mitsubishi Electric PUHY-M200YNW-A1 Service Handbook

[8-9 Troubleshooting Problems with Major Components on Hydro unit ]

8-9 Troubleshooting Problems with Major Components on Hydro
unit
8-9-1

Pressure Sensor

Troubleshooting flow chart for pressure sensor
START
Check the connectors on pressure sensor Prf,
Pw1, Pw2 for proper connections.
OK?
NO
Operating at the moment?
On the self-diagnosis monitor, measure
Outdoor high-pressure 63HS1
Outdoor low-pressure 63LS
Hydro unit pressure Prf (refrigerant side),
Pw1, Pw2 (water side)
Check whether the result is
63HS1 > Prf > 63LS
OK?
All the compressors of the outdoor units to
which the Hydro unit is connected are stopped.
10 minutes or longer after
the operation stops?
Check P1 on the self-diagnosis LED, and
check that the pressure reading is
0.098 MPa [14 psi] or above.
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 Hydro unit.
OK?
34
- chapter 8
Repair the fault.
YES
Note 1
Check whether the refrigerant pipe
NO
and the transmission line are
connected correctly between the outdoor
unit and the Hydro unit.
YES
OK?
NO
NO
NO
Is Pd P1 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 pressure sensor, which detects
less than 6MPa [870psi] pressure, with the
pressure sensor, which detects 6MPa [870psi]
or more pressure, check the pressure, and
check whether the detected pressure is
displayed normally.
OK?
YES
Replace the pressure sensor.
Note 2
NO
Note 3
Restore contact failure.
NO
NO
NO
Replace the board.
BS_08_E