Toshiba MMD-AP0071SH-C Service Manual page 100

Check code name Check code name
[P04] / [21] Actuation of
high-pressure SW
(d07 / AI-NET)
Sub-code: 01: Compressor 1 side 02: Compressor 2 side
NO
Does high-pressure SW operate? Is circuit cabling normal?
YES
NO
Are parts of high-pressure SW normal?
YES
NO
Is service valve fully opened?
YES
Abnormal
Check mispiping of
discharge/suction gas main pipes.
Normal
Abnormal
Check operation of PMV3 SV12 valve.
Normal
Abnormal
Is the flow selector normal?
Normal
All cooling operation
Reset power supply, and start a test
operation corresponded to the season.
All heating operation
Are characteristics of
high-pressure sensor normal?
B All cooling operation
NO
Is there no crack or
Does cooling outdoor fan normally operate?
YES
Is there a cause to interfere operation
YES
of heat exchanger of outdoor unit?
1. Heat exchanger clogging
2. Air short circuit
NO
NO
Is SV2 circuit normal?
YES
A
Cause of operation
1. High-pressure SW error
2. Service valve closed
3. Pd sensor error
4. Indoor/outdoor fan error
5. Indoor/outdoor PMV choke
6. Indoor/outdoor heat exchanger clogging, air short circuit
7. SV2 circuit error
8. SV4 circuit error
9. SV5 circuit error
10. Discharge line check valve malfunction
11. Refrigerant overcharge
Note) High-pressure SW is normally closed.
(B contact)
NO
Check and correct cabling.
YES
Check I/F P.C. board.
Failure Replace
Check parts.
Failure Replace
Open service valve fully.
Correct piping.
Replace defective parts.
Repair the flow selector unit.
To B
To C
Replace the high-pressure sensor.
NO
Repair faulty parts.
coming-off of fan?
Connector connection,
YES
fan IPDU, fan motor, wiring
Eliminate the interfered causes.
Repair SV2 circuit.
Coil error, clogging,
(
disconnection of wiring, etc.
A
NO
Is SV4 circuit normal?
YES
Refrigerant overcharge,
clogging,pipe breakage,
abnormal overload condition
Is indoor
PMV normal?
Is there a cause to
interfere operation of
YES
indoor heat exchanger?
1 Air filter clogging
2 Heat exchanger clogging
3 Air short circuit
Eliminate the
interfered causes.
NO
Is 4-way valve normal?
Replace 4-way valve.
NO
Is SV11 circuit normal?
Repair faulty position.
NO
Are not indoor units of different
refrigerant circuit connected?
YES
Check and
correct the cabling.
Check code name
[P05] / [AF] Open phase, negative phase
(d07 / AI-NET)
• Check the phase power line of outdoor unit.
)
• Check error of outdoor I/F P.C. board.
• Check there is no looseness, etc of terminal.
C All heating operation
Repair SV4 circuit.
( )
Coil error, clogging,
disconnection of wiring, etc.
All heating operation
YES
Does heating indoor fan
normally operate?
Is connector
NO NO
connection,
coil normal?
YES
YES
Repair
faulty parts.
Are connector connection,
heat exchanger, fan, and
fan motor normal?
NO
YES
Are characteristics of TC2
YES
and TCJ sensor resistance
value normal?
YES
YES
NO
Is there clogging
Check indoor P.C. board.
of valve? Failure
YES
Check with miscabling check
( )
function of outdoor unit.
Refrigerant overcharge, clogging,
pipe breakage, abnormal overload condition
Check code name Cause of operation
1. Power supply open phase
2. Power supply negative phase
NO
NO
Repair
faulty parts.
NO
Replace TC2
or TCJ sensor.
Replace
Replace PMV body.