Operation Check/Drain Pump Test Run Operation Mode - Mitsubishi Electric FDT125VNVF Technical Manual

Indoor unit performs the control A or B depending on each operating condition.
(b)
Stop
Compressor ON
Compressor OFF
Control A
1)
a) If the float switch detects any anomalous draining condition, the unit stops with the anomalous stop (displays E9)
and the drain pump starts. After detecting the anomalous condition, the drain motor continues to be ON.
b) It keeps operating while the float switch is detecting the anomalous condition.
Control B
2)
If the float switch detects any anomalous drain condition, the drain motor is turned ON for 5 minutes, and at 10
seconds after the drain motor OFF it checks the float switch. If it is normal, the unit is stopped under the normal
mode or, if there is any anomalous condition, E9 is displayed and the drain motor is turned ON. (The ON condition is
maintained during the drain detection.)

(13) Operation check/drain pump test run operation mode

(a) If the power is turned on by the dip switch (SW7-1) on the indoor PCB when electric power source is supplied, it enters the
mode of operation check/drain pump test run. It is ineffective (prohibited) to change the switch after turning power on.
(b) When the communication with the remote controller has been established within 60 seconds after turning power on by the
dip switch (SW7-1) ON, it enters the operation check mode. Unless the remote controller communication is established, it
enters the drain pump test run mode.
Note (1) To select the drain pump test run mode, disconnect the remote controller connector (CNB) on the indoor PCB to shut down the remote controller
communication.
(c) Operation check mode
There is no communication with the outdoor unit but it allows performing operation in respective modes by operating the
remote controller.
(d) Drain pump test run mode
As the drain pump test run is established, the drain pump only operates and during the operation protective functions by
the microcomputer of indoor unit become ineffective.
(14) Cooling, dehumidifying frost protection
(a) To prevent frosting during cooling mode or dehumidifying mode operation, the of compressor speed is reduced if
the indoor heat exchanger temperature (detected with Th
compressor operation. If the indoor unit heat exchanger temperature is 1.0 °C or lower after 1 minutes, the compressor
speed is reduced further. If it becomes 2.5 °C or higher, the control terminates. When the indoor heat exchanger
temperature has become as show below after reducing the compressor speed, it is switched to the fan operation. For the
selection of indoor fan speed, refer to item 2).
(b) Selection of indoor fan speed
If it enters the frost prevention control during cooling operation (excluding dehumidifying), the indoor unit fan speed is
switched.
1) When the indoor return air detection temperature (detected with Th
exchanger temperature (detected with Th
of indoor unit fan speed is increased by 20rpm.
2) If the phenomenon of 1) above is detected again after the acceleration of indoor unit fan, indoor unit fan speed
is increased further by 20rpm.
Note (1) Indoor unit fan speed can be increased by up to 2 taps.
• Compressor frequency drop start temperature
Item
Temperature - Low (Factory default)
Temperature - High
Note (1) Frost prevention temperature setting can be selected with the indoor unit function setting of the wired remote controller.
Indoor unit operation mode
(1) Cooling Dehumidifying
Control A
Control B
Fan operation
Indoor heat exchanger temperature (°C)
Symbol
(2)
Fan Heating
Note (1) Including the stop from the cooling, dehumidifying, fan
-R) drops to 1.0 °C or lower at 4 minutes after the start of
I
Cooling operation
1.0 10
-R) detects the compressor frequency drop start temperature A°C+1°C,
I
A
1.0
2.5
305
- -
'12 • PAC-T-174
and heating, and the anomalous stop
(2) Including the "Fan" operation according to the
mismatch of operation modes
Symbol
Model
SRC40~60
FDC100~140
-A) is 23°C or higher and the indoor heat
I
A B C
4 1 1.0
4 1 1.0