Toshiba MMU-P0121H Service Manual page 92

- ( * 1) 2-way valve leakage/blockage check procedure
1. After resetting power supply, start a trial operation.
2. Set SW01/SW02/SW03 on interface P.C. board to
1/16/1, respectively.
3. Check display on 7 segment of interface P.C. board.
In case of judgment result "A0" → Oil level is adequate. Resume the operation.
In case of judgment result "A1" → Oil level is insufficient. Check the following items.
3. Remove SV3C valve connector, reset the power
supply, and start a trial operation.
4. After operation for several minutes, check
temperature at secondary side of SV3C valve
(A in the right figure).
→ When temperature is high (Equivalent to
discharge temp.), leakage occurs from
SV3C valve.
Replace SV3C valve.
5. Remove SV3A valve connector, and start a trial
operation under condition that AC220V–240V-
power is on to SV3C valve.
6. After operation for several minutes, check
temperature at secondary side of SV3A valve
(B in the right figure).
→ When temperature is high (Equivalent to discharge temp.), leakage occurs from SV3A valve.
Replace SV3A valve.
7. Using charge hose, etc., connect the check joint of gas pipe and the charge port of balancing pipe.
8. Start a trial operation under condition that AC220–240V, 50Hz (
valve.
9. After operation for several minutes, check temperature at secondary side of SV3B valve (C in the right
figure).
→ When temperature is low (Equivalent to suction temp.), blockage occurs in SV3B valve or strainer.
Replace blockage part.
( * 2) Blockage check procedure for oil return circuit of oil separator
1. Check temperature of oil circuit during operation of outdoor unit.
→ If temperature is low, clogging occurs in capillary or strainer. Replace blocked part.
Check code
[d8]
TK1 temperature detection circuit alarm
Is TK1 sensor out of place?
NO
Is there miswiring of
TK1/TK2/TK3 sensor?
NO
Is resistance value characteristics
of TK1 sensor normal?
NO
Check interface P.C. board.
When operation has started
During detection of oil level
Judgment result of oil level
TK1
sensor
Capillary
A
tank Check
SV3A
valve
Check
B
valve
Balancing pipe valve
TK1 sensor out of place, miswiring, resistance value
characteristics error
YES
YES
YES
3-89
Check joint
SV3C valve
Strainer Oil
separator
Strainer
TK2
sensor
Compressor
Oil
Oil
removal
valve
valve
Strainer
AC220V, 60Hz ) power is on to SV3B
Operation cause
Modify sensor mounting.
Modify miswiring.
TK1 sensor : CN516
[
TK2 sensor : CN515
TK3 sensor : CN507
Sensor error.
7 segment display
"OL" "– –"
"OL" "FF" or "Numeral"
"OL" "A0" or "A1"
Capillary
Accumulator
C
Check
SV3B
valve
valve
]