Outline Of Heating Operation - Mitsubishi Heavy Industries SRK20ZFX-S Technical Manual

4.9 Outline of heating operation

(1) Operation of major functional components in heating mode
Functional
components
Indoor fan motor
Flap and louver
Display
52C
Outdoor fan motor
4-way valve
Electronic expansion valve
(2) Air flow selection
(a) Speed of inverter changes within the range of selected air flow.
Air flow selection
Inverter command speed
Auto
Air flow
Inverter command speed
HI
Air flow
Inverter command speed
MED
Air flow
Inverter command speed
LO
Air flow
(b) When the defrosting, protection device, etc. is actuated, operation is performed in the corresponding mode.
(c) Outdoor unit blower operates in accordance with the inverter command speed.
(3) Details of control at each operation mode (pattern)
(a) Fuzzy operation
Deviation between the room temperature setting correction temperature and the suction air temperature is calculated in
accordance with the fuzzy rule, and used for control of the air capacity and the inverter speed.
(b) Heating thermostat operation
¡ Operating conditions
If the speed obtained with the fuzzy calculation drops below -24 rps during the heating fuzzy operation, the operation
changes to the heating thermostat operation.
¡ Detail of operation
Item
Inverter speed
Indoor fan
Outdoor fan
Flap and louver
(c) Hot keep operation
If the hot keep operation is selected during the heating operation, the indoor blower is controlled based on the temperature of
the indoor unit heat exchanger (detected with Th2, indoor unit heat exchanger sensor) to prevent blowing of cool wind.
¡ Normal mode (Normal heating operation, operation after HI POWER completion)
Indoor fan
4th speed
3rd speed
1st speed
OFF
A B 20~35: 23°C
50: 20°C
Note (1) Refer to the table shown above right for the values A and B.
Item
When the inverter
speed is 0rps
ON
ON or OFF
Lights up
ON
OFF (20, 25, 35 type)
Depending on the stop mode (50 type)
Depending on the stop mode
Model
SRK20ZFX-S
Model
SRK20ZFX-S, 25ZFX-S, 35ZFX-S
0rps [Comp. stopped]
7th speed
6th speed
5th speed
28 29.5 31.5 34
Indoor heat exchanger temp. (˚C)
When the inverter speed
is other than 0rps
ON
ON or OFF
Lights up
ON
ON
ON
Depending on the EEV control
SRK25ZFX-S
30~94rps
Depends on inverter command speed.
30~94rps
30~66rps 30~72rps
30~38rps 30~42rps
10 rps [10sec.] → 0rps [Comp. stopped]
Hot keep normal mode → 1st speed
6th speed [1min.] → stop
Stop
Horizontal, center
(20, 25, 35 only)
9th speed
8th speed
36 37.5 39
16
- -
When the inverter speed is 0rps
due to an anomalous stop
OFF
Stop position control
Lights up or flashes
OFF after stop mode
OFF (20, 25, 35 type)
Depending on the stop mode (50 type)
Depending on the stop mode
SRK35ZFX-S
30~102rps
30~102rps
8th speed fixed
30~76rps
6th speed fixed
30~46rps
4th speed fixed
SRK50ZFX-S
¡ Values of A, B
At 0 rps command
Other than 0 rps
command
40
SRK50ZFX-S
20~120rps
20~120rps
20~80rps
20~38rps
A B
22 25
17 19