Toshiba MMU-AP0121MH User Manual
Page 86
86
Check code name
[P19]
Check code name
4-way valve operation error
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
Auxiliary code : Detected outdoor unit No.
Replace sensor.
Replace sensor.
Does not discharge
refrigerant gas bypass to
suction side through
4-way valve?
*
1
Check 4-way valve.
If an error did not occur
in test operation,
restart the operation.
Does 4-way valve operate?
Is the flow selector unit normal?
4-way valve error
Is 4-way valve coil
connector connected?
Are TS1, TE1, Pd, Ps sensor
connectors connected?
Are characteristics of resistance value
of TS1 and TE1 sensors normal?
Are output voltage characteristics
of Pd and Ps sensors normal?
Are connection and installation
of TE1 and TL sensors correct?
Reset the power supply and
start heating test operation.
Correct connector connection.
(4-way valve coil: CN317)
Correct connection
and installation.
*
1 Check TS and TE temperature of the outdoor unit which compressors is operated.
(I/F) SW01=[1], SW02=[6], SW03=[2]
®
TS sensor temperature
SW01=[1], SW02=[7], SW03=[2]
®
TE sensor temperature
≤
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)
Correct connector connection.
TS1 sensor: CN504
TE1 sensor: CN505
Pd sensor: CN501
Ps sensor: CN500
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
Replace the FS unit.
NO
NO
YES
Check code name
[P20]
Check code name
High-pressure protective operation
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
Reset power supply, and start a test
operation corresponded to the season.
Open service valves fully.
Check parts.
Failure
Replace
1. Pressure by pressure gauge (Check joint)
2. Pressure display on 7-segment display
3. Output voltage of I/F P.C. board
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.
Is there a cause to interfere operation
of heat exchanger of outdoor unit?
1. Heat exchanger clogging
2. Air short circuit
Refrigerant overcharge, clogging,
pipe breakage, abnormal overload condition
(Connector connection, fan IPDU, fan motor, wiring)
YES
YES
YES
YES
Normal
Normal
Normal
YES
NO
NO
YES
YES
YES
YES
NO
NO
Correct piping.
Correct faulty parts.
Correct faulty parts.
(Connector connection wiring, coil mounting, valve clogging, etc)
NO
Correct faulty position.
(Coil error, clogging, disconnection of cable, etc.)
NO
Repair SV2 circuit.
(Coil error, clogging, disconnection of cable, etc.)
NO
Repair SV4 circuit.
NO
Repair check valve.
Replace
Abnormal
Replace defective parts.
Abnormal
Repair the flow selector unit.
Eliminate the interfered causes.
Abnormal
NO
All cooling operation
To B
All heating operation
To C
Is SV2 circuit normal?
Is SV4 circuit normal?
Is outdoor PMV1, 2 normal?
Is there no fan crack or coming-off?
B All cooling operation
Are service valves fully opened?
Check operation of PMV3 SV12.
Is the flow selector unit normal?
Does check valve of main
discharge pipe normally operate?
Does cooling outdoor fan normally operate?
Are characteristics of
high-pressure sensor normal?
Check mispiping of discharge gas/
suction gas main pipes.