Toshiba MiNi-SMMS MCY-MAP0501HT Service Manual page 133

Check code Check code name
[H04] / [44] Compressor 1 case thermo operation
(TCC-L / AI-NET)
Is case thermo circuit normal?
NO
1. Connector connection
2. Wiring
(Note 1)
3. I/F P.C. board (Note 1)
1. Case thermo is usually closed.
2. Operation temperature of case thermo is 120˚C.
YES
Are service valves of NO
gas pipe and liquid pipe of
outdoor unit fully opened?
YES
Are outdoor PMV normal?
NO
1. Connector connection
2. Wiring 3. Coil
Connector CN300, White
4. Valve body 5. I/F P.C. board
YES
Start operation.
Are SV4
Valve circuits normal?
NO
1. Incorrect installation and
connection of SV4
SV4 valve: Connector CN311, Blue
2. Leakage from SV4 circuit
YES
Does not refrigerant
YES
bypass from discharge to
suction through 4-way valve?
NO
YES
Is not refrigerant bypassed
from discharge to suction?
NO
NO
Is compressor normal? (Note 2)
YES
(Note 2) Check the following items mainly.
1. Existence of abnormal sound and abnormal vibration during operation or when starting
2. Abnormal overheat of case during operation or stop (Do not touch.)
3. Current of compressor during operation or starting (No rapid current change)
YES
Is flow selector unit normal?
NO
Refrigerant shortage,
(After checking there is no slogging or pipe breakage, charge refrigerant again.)
clogging, pipe breakage
Cause of operation
1. Case thermo circuit error
2. I/F P.C. board error
3. Service valve closed
4. Outdoor PMV clogging
5. SV4 valve leak, Coil misinstallation
6. 4-way valve error
7. Compressor error
8. Refrigerant shortage
Repair case thermo circuit.
Open service valves fully.
Repair outdoor PMV.
Correct SV4
valve circuits.
Check 4-way valve.
Check piping.
Compressor error
Check flow selector unit.
Check code Check code name
[H06] / [20] Low-pressure
protective operation
(TCC-L / AI-NET)
NO
Are service valves of gas and
liquid pipe of outdoor unit fully opened?
YES
NO
Are characteristics of low-pressure sensor normal?
* 1 Pressure by pressure gauge (Check joint)
YES
2 Pressure display on 7-segment display
3 Output voltage of I/F P.C. board
NO
Are SV2 and SV4 circuits normal?
YES
YES
Is indoor unit connected to different refrigerant systems?
NO
(Check with miswiring check function of outdoor unit.)
In cooling season, go to (A), in heating season, go to (B)
(A) Cooling
NO
Does indoor fan operate
normally in cooling season?
YES
YES
Is there clogging of indoor
Cleaning
air filter or heat exchanger?
NO
NO
Is the PMV Kit used?
YES
NO
Is the PMV built in the indoor unit
made full open?
YES
Is the connection cable NO
between PMV Kit and indoor unit
connected certainly?
YES
NO
Is the PMV of "PMV Kit" normal?
YES
Refrigerant shortage or
clogging or pipe deformed.
(B) Heating
NO
Is outdoor fan operating
normally in heating season?
YES
YES
Is there clogging of
Cleaning
outdoor heat exchanger?
NO
NO
Is outdoor PMV normal?
YES
Refrigerant shortage or
clogging or pipe deformed.
Cause of operation
1. Service valve close
2. Ps sensor error
3. SV2, SV4 circuit error
4. Miscabling of communication between indoor and outdoor
5. Indoor/outdoor fan and condenser error
6. Indoor/outdoor PMV clogging
7. Indoor/outdoor heat exchanger clogging
8. Refrigerant shortage
Open service valves fully.
Exchange low-pressure sensor.
If 1 and 2, 3 are different, an error of pressure sensor error is considered.
If 2 and 3 are different, check I/F P.C. board.
Correct SV2 and SV4 circuits.
Correct cabling.
Are following items normal?
1. Connection NO
2. Condenser
Repair faulty parts.
3. Motor
4. Fan
YES
Check indoor P.C. board.
Failure ® Replace
YES
Refrigerant shortage or
Is indoor PMV normal?
clogging or pipe deformed.
NO
PMV built in the indoor unit
is made full open.
Connection
NO
Is connection or coil normal? Repair faulty parts.
YES
YES
Is there clogging of the valve? Replace PMV body.
NO
Check indoor I/F P.C. board.
Failure ® Replace
NO
Is indoor fan system normal?
Check outdoor I/F P.C. board.
• Fan cracked
Failure ® Replace
• Fan loose
YES
Repair faulty parts.
NO
Check outdoor I/F P.C. board.
Is connection or coil normal?
Failure ® Replace
YES
Repair faulty parts.