Mitsubishi Heavy Industries SRRM40HENG-L, Handbook, Page: 1038 / 1106

1036
FDC-HKXR
(10) Condensate pump motor (DM) control (Only FDT, FDTW, FDTS, FDR, FDUM models)
(a) Drain motor is started no sooner than the compressor is turned ON during cooling or dehumidifying operation. The drain motor
continues to operate for 2 minutes after the stop of unit operation, stop with the error stop, thermostat stop and at switching
from cooling or dehumidifying operation to blowing or heating operation. When there is any unit subjected to oil return
control, the drain motor is operated for 3 minutes at such occasion.
Note (1) Drain motor may be operated forcibly by turning ON the dip switch SW
5-3
on the PCB. Turn the switch OFF to stop the drain motor.
(b) Overflow detection is always operable by means of the float switch regardless of operation modes. If the overflow is detected
(or when the float switch is disconnected or its wire is broken), operation is stopped with the error stopped. (FDT, FDTW,
FDTS, FDR and FDUM) If the overflow is detected while the drain motor is stopped, the drain motor is operated for 3 minutes
and then the overflow detection is performed to judge whether it is normal or not.
* 1 In the flow in the frame of broken line, operations of operation mode change and thermostat reset are effective and operated immediately upon selection. However,
the compressor ON command is not transmitted.
(i) Control A
a) If the float switch detects the draining, operation is stopped with the error stop (E9 is displayed) and operate the drain pump.
b) Float switch is checked 3 minutes later on the unit stopped by the error and, if the error persists still, the drain motor is left
at ON but, if the error has already been reset, the drain motor is turned OFF. E9 is displayed till the error is reset.
(ii) Control B
a) If the float switch detects the draining, the expansion valve is closed, the drain motor is turned ON for 3 minutes and, as 10
seconds elapses after the drain motor OFF, the float switch is checked. If the result is normal, the operation stops in the
normal way while, if it is not normal, E9 is displayed, the drain motor is turned ON and the operation stops with the error
stop with the expansion valve being closed completely. (It is left at ON while the draining is detected.)
During compressor ON Control A
During compressor OFF Control B
Indoor unit operation mode
OFF
(1)
COOL DRY FAN
(2)
HEAT
Notes (1) Including OFF and error stop during
COOL, DRY, FAN and HEAT.
(2) Including “FAN” operation due to unmatch
of operation mode.
•
Flow chart of drain motor operation
Drain motor ON continues
Float switch operation (Contactor : Open)
Control B
NO
*1
Operation mode?
Control A
Drain motor ON
3 minutes
after float operation?
3 minutes
after float operation?
Drain motor OFF
10 seconds after
drain motor OFF?
Reset
YES
YES
NO
Reset
Float SW?
Float SW?
Operation
Operation
End
Error stop E9
Drain motor 3-minute ON
Error stop E9
Drain motor ON
Compressor OFF
Drain motor OFF
Error stop E9 continues
Float operation?