Toshiba MMU-AP0152SH Service Manual page 88

Check code name Check code name
[P19] / [08] 4-way valve operation error
(d07 / AI-NET)
Sub-code: Detected outdoor unit No.
NO
Is 4-way valve coil
connector connected?
YES
NO
Are TS1, TE1, Pd, Ps sensor
connectors connected?
YES
NO
Are characteristics of resistance value
of TS1 and TE1 sensors normal?
YES
NO
Are output voltage characteristics
of Pd and Ps sensors normal?
YES
NO
Are connection and installation
of TE1 and TL sensors correct?
YES
Reset the power supply and
start heating test operation.
NO
Is the flow selector unit normal?
YES
Does not discharge
YES
refrigerant gas bypass to
Does 4-way valve operate?
suction side through
NO
4-way valve error Check 4-way valve.
1 Check TS and TE temperature of the outdoor unit which compressors is operated.
(I/F) SW01=[1], SW02=[6], SW03=[2]
SW01=[1], SW02=[7], SW03=[2]
<Judgment criteria>
TE sensor: Normal if TE £ 20˚C except summer season (Outside temp 20˚C or lower)
TS sensor: Normal if TS £ 40˚C except summer season (Outside temp 20˚C or lower)
Cause of operation
1. 4-way valve error
2. TS1 sensor/TE1 sensor error
3. Pd sensor/Ps sensor error
4. TE sensor/TL sensor misconnection
Correct connector connection.
(4-way valve coil: CN317)
Correct connector connection.
TS1 sensor: CN504
TE1 sensor: CN505
Pd sensor: CN501
Ps sensor: CN500
Replace sensor.
Replace sensor.
Correct connection
and installation.
Replace the FS unit.
If an error did not occur
NO
in test operation,
restart the operation.
4-way valve? 1
YES
TS sensor temperature
TE sensor temperature
Check code name Check code name
[P20] / [22] High-pressure protective operation
(d07 / AI-NET)
NO
Are service valves fully opened?
YES
NO
Are characteristics of
high-pressure sensor normal?
YES
Abnormal
Check mispiping of discharge gas/
suction gas main pipes.
Normal
Abnormal
Check operation of PMV3 SV12.
Normal
Abnormal
Is the flow selector unit normal?
Normal
All cooling operation
Reset power supply, and start a test
operation corresponded to the season.
All heating operation
1. Pressure by pressure gauge (Check joint)
2. Pressure display on 7-segment display
3. Output voltage of I/F P.C. board
B All cooling operation
If 1 and 2, 3 are different, an error of pressure sensor is considered.
If 2 and 3 are different, check I/F P.C. board.
NO
Does cooling outdoor fan normally operate?
YES
YES
Is there no fan crack or coming-off?
NO
NO
Is outdoor PMV1, 2 normal?
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
NO
Is SV4 circuit normal?
YES
NO
Does check valve of main
discharge pipe normally operate?
YES
Refrigerant overcharge, clogging,
pipe breakage, abnormal overload condition
Cause of operation
1. Pd sensor error
2. Service valve closed.
3. Indoor/outdoor fan error
4. Indoor/outdoor PMV clogging
5. Indoor/outdoor heat exchanger clogging
6. SV2 circuit error
7. SV4 circuit error
8. SV5 circuit error
9. Outdoor I/F P.C. board error
10. Operation error of check valve of main
discharge pipe
11. Refrigerant overcharge
Open service valves fully.
Check parts.
Failure Replace
Correct piping.
Replace defective parts.
Repair the flow selector unit.
To B
To C
Correct faulty parts.
Correct faulty parts.
(Connector connection, fan IPDU, fan motor, wiring)
Correct faulty position.
(Connector connection wiring, coil mounting, valve clogging, etc)
Eliminate the interfered causes.
Repair SV2 circuit.
(Coil error, clogging, disconnection of cable, etc.)
Repair SV4 circuit.
(Coil error, clogging, disconnection of cable, etc.)
Repair check valve. Replace