Service manual

24
2. INDOOR UNIT CONTROL
2-1COOL operation
(1) Compressor control
1 3-minute time delay
To prevent overload, the compressor will not start within 3 minutes after stop.
2 The compressor runs when room temperature is higher than set temperature.
The compressor stops when room temperature is equal to or lower than the set temperature.
3 The compressor stops in check mode or during protective functions.
4 Coil frost prevention
To prevent indoor coil frost, the compressor will stop when the indoor coil thermistor (RT2) reads 1°C or below after the
compressor has been continuously operated for at least 16 minutes or more. The coil frost prevention is released under any
of the following conditions.
● The indoor coil thermistor rises to 10°C or above.
● The room temperature becomes equal to or lower than the set temperature.
● COOL mode is stopped or changed to another mode.
NOTE : By cutting the jumper wire JRO2 on the indoor controller board, the temperature to start coil frost prevention
changes from 1°C to -3°C.
5 Coil frost protectiony
When indoor coil temperatuer becomes -15°C or below, coil frost protection will proceed as follows.
<Start condition>
After the compressor has been continuously operated for 3 minutes or more, and the indoor coil temperature has been -15°C
or below for 3 minutes, the coil frost protection will start.
<Coil frost protection>
Compressor stops for 6 minutes, and then restarts.
If the start condition is satisfied again during the first 10 minutes of compressor operation, both the indoor and outdoor units
stop, displaying a check code of ¨P6¨ on the remote controller.
<How to operate>
1 Press POWER ON/OFF button.
2 Press MODE SELECT button to set operation mode to COOL.
3 Check lamp is ON and set desired temperature with UP
or DOWN button.
NOTES : 1. When lamp is ON, press TIMER/TEMP button
to change the display to temperature mode.
2. Set temperature changes by 1°C in the range 18 ~ 29°C
each time UP or DOWN button is pressed.
3. The lighting lamp shows the set temperature, and the
flashing lamp shows the room temperature.
When the room temperature is equal to the set tempera-
ture, the lamp keeps lighting, 0.5 seconds brightly and
0.5 seconds faintly.
TIMER
TEMP.
MIN. 3 minutes w1
ON
Thermostat
Indoor fan
Louver
Compressor
ON
LOW or HIGHLOW or HIGH
ON
OFF
OFF
ON
OFF
OFF
Operation starts by
POWER button
ON.
Operation stops by
POWER button
OFF.
Room temperature
becomes equal to
set temperature.
Room temperature
rises above set
temperature.
Depends on remote controller setting
<COOL operation time chart>
w1 Even if the room temperature rise above the set temperature during this period, the compressor will not start until this period has ended.
MITSUBISHI ELECTRIC
12
11
10
9
8
7
6
5
4
3
2
1
29
28
27
26
25
24
23
22
21
20
19
18
TIMER TEMP
TIMER/TEMP.
UP
DOWN
POWER
COOL
ON/OFF
LOUVER
MODE
SELECT
FAN
SPEED
TIMER
MODE
DRY
FAN
HIGH
LOW
ON
AUTO
STOP
START