Troubleshooting Chart; Troubleshooting Procedure; Basic Check Items - Toshiba RAS-24UAH-E-1 Service Manual

9-1. Troubleshooting Procedure :

Follow the details of 9-2. Basic Check Items.
If there is no trouble corresponding to 9-2, check
whether or not there are faulty parts following
9-4. Self-Diagnosis by Remote Control.

9-2. Basic Check Items

9-2-1. Power supply voltage
The line voltage must be AC 220 – 240 V. If it is not
within this range, the air conditioner may not operate
normally.
No. Operation of air conditioner
1 When the main power supply is turned
on, the OPERATION lamp on the
indoor unit blinks.
2 The indoor fan motor speed does not
change in the Dry operation.
3 The compressor is not turned off even
though the room temperature is in the
range that the compressor is turned off.
4 The compressor is not turned on and
off even though the thermo control is
operated in the Dry operation.
*5 The PRE-DEF. lamp is indicated when
the Heating operation starts.
*6 The outdoor fan motor stops in the
Heating operation.
7 The compressor is not turned on even
though the room temperature is in the
range that the compressor is turned on.
8 The operation mode changes in the
Automatic operation.
9 The Fan only operation continues in the
Automatic operation.
10 The ECO operation or Hi-POWER
operation does not work.
11 When [Hi POWER] button is pressed,
the display on the remote control does
not change at all.
Note *5 and *6 are for Heat pump model :

9. TROUBLESHOOTING CHART

9-2-2. Incorrect cable connection between Indoor
The indoor unit is connected to the outdoor unit with
4 cables. Check that the indoor and outdoor units have
been properly connected with terminals assigned the
same numbers. If the connectors are not properly
connected, the outdoor unit will not operate normally,
or OPERATION lamp and TIMER lamp will blink (5 Hz).
9-2-3. Program control
The microcontroller operates as shown in Table 9-2-1
to control the air conditioner. If there are any opera-
tional problems, check whether or not the problems
correspond to Table 9-2-1. If they correspond to the
Table, they are not problems with the air conditioner,
but they are indispensable operations to control and
maintain the air conditioner properly.
Table 9-2-1
The OPERATION lamp blinks to indicate that power is turned on. If the
[START/STOP] button is pressed, the lamp stops blinking.
The indoor fan motor speed is automatically controlled in the Dry
operation.
The compressor has a function that it is not turned off for 3 minutes
after it is turned on even though the room temperature is in the range
that the compressor is turned off.
In the Dry operation, the compressor is turned on and off automatically
at the regular intervals, independent of the thermo control.
The PRE-DEF. lamp is indicated during the Defrosting operation or if
the indoor heat exchanger temperature is low when the Heating
operation starts. At this time, the indoor fan motor stops to prevent
cold air from blowing in the room.
When the indoor heat exchanger temperature is high, the outdoor fan
motor is stopped by the high-temperature limit control operation.
The compressor is not turned on in the restart delay timer (3-minutes
timer) operation. It is also not turned on after the power supply is
turned on because of this timer operation.
In Automatic operation, the room temperature is detected all time
for control fan speed and the operation mode is changed every
15 minutes according to difference between the room temperature
and the preset temperature.
When the room temperature is in the range
(Preset temperature ± 1°C), the Fan only operation is selected.
These operations do not work when the unit is in the Dry
operation or Fan only operation.
The display on the remote control does not change when
[Hi POWER] button is pressed. However the microcontroller gives
commands to change the preset temperature and air flow level.
– 55 –
FILE NO. SVM-03010(1)
and outdoor units
Descriptions