Mitsubishi Heavy Industries 140KXZEN1 Service Manual Download

Page: 17 / 166

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'17 • KX-SM-272

(12) Drain pump abnormalities detection

(a)

Drain detection switch is turned ON or OFF with the float switch (FS) and the timer.

[

＊

1] Drain detection switch is turned “ON” when the float switch “Open” is detected for 3 seconds continuously in the

drain detectable space.

[

＊

2] Drain detection switch is turned “OFF” when the float switch “Close” is detected for 10 seconds continuously.

(i) It detects always from 30 seconds after turning the power ON.

1) There is no detection of anomalous draining for 10 seconds after turning the drain pump OFF.
2) Turning the drain detection switch “ON” causes to turn ON the drain pump forcibly.
3) Turning the drain detection switch “OFF” releases the forced drain pump ON condition.

(b)

Indoor unit performs the control A or B depending on each operating condition.

Normal state

[*1]

[*2]

Normal state

Drain detection switch ON

Stop

(1)

Indoor unit operation mode

Control A

Control B

Compressor ON

Compressor OFF

Cooling

Dry

Heating

Fan

(2)

Notes (1) Including the stop from the cooling, dehumidifying, fan

and heating, and the anomalous stop

(2) Including the “Fan” operation according to the

mismatch of operation modes

(i) Control A

1) 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.

2) It keeps operating while the float switch is detecting the anomalous condition.

(ii) Control B

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 control 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 control communication is established, it
enters the drain pump test run mode.

Note (1) To select the drain pump test run mode, disconnect the remote control connector (CnB) on the indoor PCB to shut down the remote control

communication.

There is no communication with the heat source unit but it allows performing operation in respective modes by operating
the remote control.

(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

To prevent frosting during cooling mode or dehumidifying mode operation, the of thermostat-OFF if the indoor heat exchanger
temperature (detected with Thi-R) drops to 1.0 °C or lower at 4 minutes after the thermostat-ON. If the indoor unit heat
exchanger temperature is 1.0 °C or lower after 5 minutes, the indoor unit is controlled thermostat-OFF. If it becomes 10°C or
higher, the control terminates. When the indoor heat exchanger temperature has become as show, the indoor unit send heat
source unit the “Anti-frost” signal.

1.0

Indoor heat exchanger temperature (°C)

Thermostat-OFF

5 minutes

Thermostat-ON capable

SRC40~60

FDC100~140

Model

Symbol

1.0

2.5

• Frost prevention temperature setting can be selected with the