Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 1036

FDC-HKXR
(5) Dehumidifying (Thermal dry)
• This cooling operation is mainly for dehumidifying, with which the compressor, indoor and outdoor fans are operated in the patterns as listed
in the following table and in accordance with operation blocks switched with the room temperature sensor. The operation blocks are selected
by checking the return air temperature at 4-minute intervals. Respective functional items are operated in each operation block as shown by the
following table.
D C B A
Low -2 +2 High
Room temperature
setting point
• Indoor unit fan will be operated in
D block as shown below.
Lo
OFF
4 min.
Temperature check Temperature check
(6) Heating operation
(a) Heating
• This is same as the cooling operation.
(b) Heating operation with thermostat OFF
1) Intermittent fan operation control
a) When the jumper wire J3 on the indoor PCB is shorted (installed at shipping),the fan of the unit of which the thermostat is
turned OFF during heating is operated in the Lo mode, and the indoor fan is turned OFF if the temperature rises 1˚C or more
than the return air temperature at the thermostat OFF.
b) Indoor fan OFF condition is maintained for 5 minutes and then the operation is reset at the Lo mode again. After operating
for 2 minutes in the Lo mode, return air temperature is checked and, if it is 1˚C or higher, the indoor fan is turned OFF or, if
it is not higher than 1˚C, the Lo mode operation continues.
Notes (1) If the heating thermostat has been turned OFF, the temperature is indicated on the remote controller only when the indoor fan is operated in the Lo
mode. When it is OFF, the room temperature at the end of Lo operation is indicated.
(2) If the operation is changed to the defrosting mode while the heating thermostat is at OFF or the thermostat is turned OFF during defrosting, the indoor
fan is turned OFF.
(3) Residual operation of heater is dominant over this control.
2) Fan stop control
a) If the jumper wire J3 on the indoor PCB (installed at shipment) is opened or the thermostat is turned OFF during heating
operation with the remote control sensor operating, the fan on the indoor unit is turned OFF.
(c) Hot start (Prevention of cold draft during heating)
If the required frequency in the room is other than 0 Hz at the start of heating operation, the indoor fan is controlled in
accordance with the temperature of indoor air heat exchanger (detected with Th
(Setting blow rate)
Stop
Indoor air heat exchanger temperature (˚C)
1034
Operation block
Item
22 model
28 model
36 model
45 model
56 model
71 model
90 model
112 model
140 model
Compressor
20 sec.
Indoor unit electronic expansion valve
Indoor unit fan
Outdoor unit fan
Notes(1) When the hot start (the compressor is operating and the indoor unit fan is not operating at the setting
blow rate) is going on, the heating preparation is displayed (LCD on the remote controller).
(2) When the required frequency is other than 0 Hz, once the blower should start, it will not stop even
if the temperature drops below 20˚C.
(3) After the blower has been turned OFF for 7 minutes, the blower is operated regardless of the heat
exchanger temperature. (For 7 minutes after completion of defrosting during defrosting operation)
A B
10 10
15 10
20 15
20 15
25 15
30 20
40 25
50 40
60 45
Sum of frequencies on combined indoor units
Frequency adaptation
Me Lo
Operationt Operationt
-R).
I
C D
10 0
10 0
10 0
10 0
15 0
15 0
15 0
35 0
35 0
Lo Lo↔OFF
Operationt Stop