Toshiba RAS-4M27U2AVG-E Service Manual page 78

Block distinction
Check Check
Block
code
The others
(including
compressor)
* 4, 8 or 11 times ; When first error is detected, error is count as 1 time, then once operation is stop and re-started.
After re-starting operation within 6 minutes, if same error is detected, error count is add (count become 2
times) When error count comes 4, 8, 11 or 18 times, record error to check code. But after re-starting operation,
if no error is detected and air conditioner can operate more than 6 minutes, error count is cleared.
Operation of diagnosis function
Cause of operation
code
Return signal of the outdoor
unit has been sent when
operation start. But after
that, signal is stop some time.
Instantaneous power
failure.
Some protector
(hardware) of the
outdoor unit open circuit
of signal.
Signal circuit of indoor
P.C. board or outdoor
P.C. board is failure in
some period.
TE, TC high tmperature
TE for cooling operation
TC for heating operation.
(TE only exists in
the Heat Pump system)
TE or TS sensor; abnormal.
Out of place, disconnection,
shortage, or misconnection
(TE sensor is connected to
TS connector, TS sensor is
connected to TE sensor
connector)
TE sensor; Outdoor heat
exchanger temperature
sensor
TS sensor; Suction pipe
temperature sensor
Air
Display
conditioner
flashing error
status
Indoor unit Flashes when
operates error is detected
continue.
11 times*.
Outdoor unit
Flashing stop
stop.
and outdoor unit
start to operate
when the return
signal from the
outdoor unit is
normal.
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FILE NO. SVM-18052
Action and Judgment
1. . Check power supply (Rate +10%)
2. . If the air conditioner repeat operat
and stop with interval of approx. 10 to
40 minutes.
(In case of these exist)
Check protector (hardware) such as
Hi-Pressure switch, Thermal-Relay,
etc.
Check refrigerant amount, packed
valve opening and any possibility
cause which may affect high
temperature or high pressure.
3. Check operation signal of the indoor
unit by using diode. Measure voltage at
terminal block of the indoor unit
between No.2 and No.3 (or L2 and S) If
signal is varied 15-60V continuously,
replace inverter P.C. board.
If signal is not varied, replace indoor
P.C. board.
4. Check and clean heat exchanger area
Indoor and Outdoor unit.
5. Check sensors, TE, TS connection.
In case of sensors and it's connection is
normal, check the inverter P.C. board.
6. Check 4way valve operation/position. In
case TE, TS detected temperature
relationship are different from normal
operation, "21" might be detected.