Toshiba MMU-P0121H Service Manual page 67

Check code
[21]
Inverter high-pressure SW system alarm
Does inverter
high-pressure switch operate?
YES
Are inverter high-pressure
switch parts normal?
YES
Check parts.
Defective
Is service valve fully open?
YES
Does cooling outdoor fan
normally operate?
YES
Is there a cause to hinder
heat exchanger of outdoor unit?
Blockage of heat exchanger
Short circuit
NO
Is SV2 bypass circuit normal?
YES
A
NO
NO
Replacement
NO
Open service valve fully.
NO
Are the connection, capacitor,
and fan motor normal?
YES
Is high-pressure sensor
characteristics normal?
Remove cause.
NO
YES
*
1
Repair SV2 bypass circuit.
Refrigerant over charge
Blockage
Pipe breakage
Abnormal overload
Operation cause
1. Inverter high-pressure SW error
2. Inverter IOL operation
3. Service valve closed
4. Outdoor fan, capacitor error
5. Indoor/Outdoor PMV blockage
6. Outdoor heat exchanger blockage
7. SV2 circuit blockage
8. Indoor - Outdoor communication error
9. Pd sensor error
10. Refrigerant over charge
See judgment flow of IPDU
IOL operation circuit E5.
Check and modify wiring.
NO
YES
Repair defective position.
NO
YES
Replace high-pressure sensor.
Check outdoor IPDU P.C.board.
Defective Replacement
(Coil error, disconnection of wiring, etc.)
*
1 : In cooling only model
3-64
NO
Is inverter IOL circuit normal?
YES
NO
Is circuit wiring normal?
YES