Mitsubishi Heavy Industries FDT40ZSXW1VH Service Manual Download

Page: 17 / 93

'19 • PAC-SM-302

(11) Drain pump control

(a) This control is operated when the inverter frequency is other than 0 Hz during the cooling operation and automatic

cooling and dehumidifying operations.

(b) Drain pump ON condition continues for 5 minutes even when it enters the OFF range according to (i) above after

turning the drain pump ON, and then stops. The 5-minute delay continues also in the event of anomalous stop.

(c) The drain pump is operated with the 5-minute delay operation when the compressor is changed from ON to OFF.
(d) Even in conditions other than the above (such as heating, fan, stop, cooling thermostat OFF), the drain pump control is

performed by the drain detection.

(e) Following settings can be made using the indoor function setting of the wired remote control.

(i)
(ii)
(iii)
(iv)

Note (1) Values in

〔

〕

are for the RC-EX3A model.

Standard

in cooling & dry

: Drain pump is run during cooling and dry.

Operate in standard & heating

: Drain pump is run during cooling, dry and heating.

Operate in heating & fan

: Drain pump is run during cooling, dry, heating and fan.

Operate in standard & fan

: Drain pump is run during cooling, dry and fan.

(12) Drain pump motor (DM) control

(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.

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.)

(b)

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

(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 unit control 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.