Outline Of Automatic Operation; Protective Control Function - Mitsubishi Heavy Industries SRK63ZR-WF Technical Manual

(a) Operation of major functional components in cooling mode
(17) Outline of dehumidifying (DRY) operation
(a) Purpose of DRY mode
Compressor
The purpose is "Dehumidification", and not to control the humidity to the target condition.
Indoor fan motor
Indoor/outdoor unit control the operation condition to reduce the humidity, and also prevent over cooling.
Outdoor fan motor
(b) Outline of control
4-way valve
(i) Indoor fan speed and compressor are controlled by the area which is selected by the temperature difference.
(b) Detail of control in each mode (Pattern)
1) Fuzzy operation
Indoor
fan speed
Fan speed
AUTO
HI
Compressor
MED
speed
LO
ULO
(ii) The indoor unit check the current area by every 5 minutes, and operate by the next checking.

(17) Outline of automatic operation

(a) Determination of operation mode
(c) Other
When the outside temperature and room temperature is low for cooling operation, indoor unit can not operate in cooling, and
dehumidifying. In this case, the units operate in heating to rise the room temperature and after that start dehumidifying operation.
(18) Outline of automatic operation
(a) Determination of operation mode
Operation mode is determined by indoor air temperature and outdoor air temperature as following.
Indoor air temperature (˚C)
Indoor air
temperature (˚C)
(b)
(b) Operation mode is changes when keep cooling and heating thermostat off 20 minutes and be satisfied with following conditions.
If the setting temperature is changed with the remote control, the operation mode is judged immediately.
(i)
(ii)
When both the indoor and the outdoor air temperatures are in the range "A", cooling or heating is switched depending on
the difference between the setting temperature and the indoor air temperature.
(iii)
When the operation mode has been judged following the change of setting temperature with the remote control, the hourly
judgment of operation mode is cancelled.
※It can not be changed to heating mode if outdoor air temperature is 28℃ or higher.
(c)
(c) When the unit is started again within one hour after the stop of automatic operation or when the automatic operation is
selected during heating, cooling or DRY mode, the unit is operated in the previous operation mode.
(d)
(d) Setting temperature can be adjusted within the following range. There is the relationship as shown below between the signals
of the wireless remote control and the setting temperature.
Cooling
Setting
temperature
Heating
(19) Protection control function
(a) Dew prevention control [Cooling]: Prevents dewing on the indoor unit.
(i) Operating conditions
When the following conditions have been satisfied for more than 30 minutes after starting operation.
1) Compressor's command speed is 28 rps or higher.
2) Detected value of humidity is 68% or higher.
Thermostat ON
ON
ON
ON
OFF
Indoor fan speed
D C
ULo(Lo) speed
STOP
Model
SRK63ZR-WF
12-106rps
12-106rps
12-68rps
Minimum
12-50rps
STOP
12-32rps
Difference between set temperature and return temperature
27.5
25.5
18.0
SP
Heating
Outdoor air temperature (˚C)
Keep operation
mode
Heating
SP － 1
Indoor air temperature (˚C)
18 19
20 21
19 20
Cooling
Thermostat OFF
OFF
ON
OFF
(few minutes ON)
OFF
Area
B
Me speed
SRK71ZR-WF SRK80ZR-WF
Limited （Lower than
20-98rps
normal cooling operation）
20-76rps
20-98rps
20-76rps
Limited
20-64rps
20-56rps
（Lower than the speed in"Area A"）
20-46rps
20-40rps
20-26rps 20-26rps
Set temperature
A Dehumidifying
Cooling
Heating
SP: Setting temperature
18
Outdoor air temperature (˚C)
28
Cooling
SP: Setting temperature
SP ＋ 1
Signals of wireless remote control (Display)
20 21 22 23 24
22 23 24 25 26
21 22 23 24 25
45
- -
Failure
'22 • SRK-T-362
OFF
OFF
OFF
(few minutes ON)
OFF
A
Cooling
30
25 26 27 28
27 28 29 30
26 27 28 29
29 30
31 32
30 31