MITSUBISHI ELECTRIC P500YMF-C User Manual

Page 92

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Troubleshooting the major components of the BC controller

1) Pressure sensor

Pressure sensor troubleshooting flow

Check on the LED monitor dis-
play.

• TH2 or LPS of outdoor unit.
• HPS of outdoor unit
• PS1, PS3 of BC controller and

confirm the following relationship
HPS > PS1

PS3 > TH2 or LPS

(puressure calculated value)

Check that refrigerant pip-
ing and transmission line
connections are in agree-
ment between outdoor
unit and BC controller.

START

Check pressure sensor, PS1,
PS3, connectors for discon-
nection, looseness, or incor-
rect attachment.

OK?

Stop the unit (compres-
sor OFF).

At least

10 minutes passed since

stopping?

Check PS1, PS3 on LED
monitor display and confirm
that none of the detected
pressure values is below
1kg/cm

G (0.098MPa).

OK?

Change board.

Repair faulty connection.

Change pres-
sure sensor.

OK?

Replace the wrong
puressure sensor with the
correct pressure sensor, and
confirm It’s detected pres-
sure is indicated correctly.

Short connectors 2 and 3 on the
board and check the pressure.

Pressure

range within 0 to 1kg/cm

(0.098MPa)

Pressure

of at least 32kg/cm

(3.14MPa) indicated?

Remove the pressure sensor
connector from the board, and
check the pressure.

Check for faulty connector on
applicable pressure sensor.

Correct refrigerant
piping and trans-
mission line.

OK?

Note 3

Take corrective action.

HPS PS1 PS3 TH2
or LPS (pressure calcu-
lated value) (The differ-
ence is less than 1kg/
cm

G (0.098MPa)

No board or pressure
sensor abnormality.

Check that refrigerant piping and
transmission line connections are
in agreement between outdoor
unit and BC controller.

Confirm the

following relationship PS1

PS3?

Correct refrigerant
piping and the trans-
mission line.

Unit running?

Note 1

Note 2

Yes

Note 4

Yes