Mitsubishi Heavy Industries FDT90VNPWVH Service Manual page 12

(ii) Regardless of the setting temperature, the cooling or heating operation mode is judged according to the "Judgment based on
(ii) Regardless of the setting temperature, the cooling or heating operation mode is judged according to the "Judgment
Room temperature/Cooling or Heating and Outdoor temperature/Cooling or Heating".
based on Room temperature/Cooling or Heating and Outdoor temperature/Cooling or Heating".
1) In case of "Room temperature/Cooling < Indoor return air temperature" and "Outdoor temperature/Cooling < Outdoor air tem
1) In case of "Room temperature/Cooling < Indoor return air temperature" and "Outdoor temperature/Cooling < Out-
perature" ⇒ Operation mode: Cooling
door air temperature" ⇒ Operation mode: Cooling
2) In case of "Room temperature/Heating > Indoor return air temperature" and "Outdoor temperature /Heating > Outdoor air tem 2)  I n case of "Room temperature/Heating > Indoor return air temperature" and "Outdoor temperature /Heating > Out-
perature" ⇒ Operation mode: Heating
door air temperature" ⇒ Operation mode: Heating
3) The outdoor air temperature of the above judgment conditions is sampled at every 10 minutes.
3) The outdoor air temperature of the above judgment conditions is sampled at every 10 minutes.
4) In the range where the above cooling and heating zones are overlapped ⇒ Forced thermostat OFF
4) In the range where the above cooling and heating zones are overlapped ⇒ Forced thermostat OFF
30
28
26
24
22
20
18
16
14
12
12
(2) Operations of functional items during cooling/heating
(2) Operations of functional items during cooling/heating
Operation
Operation
Thermostat
Thermostat
Functional item
Functional item
Compressor
Compressor
4-way valve
4-way valve
Outdoor unit fan
Outdoor fan
Indoor unit fan
Indoor fan
(3)
(3)
Drain pump
Drain pump
Notes (1) : Operation
Notes (1) : Operation Í: Stop
(2) ON during the drain pump motor delay control.
(2) ON during the drain pump motor delay control.
(3) Drain pump ON setting may be selected with the indoor unit function setting of the wired remote control.
(3) Drain pump ON setting may be selected with the indoor unit function setting of the wired remote control.
(3) Dehumidifying (DRY) operation
(a) FDT series
Indoor ambient temperatures and humidity are controlled simultaneously with the relative humidity sensor (HS) and the
suction temperature sensor [Thi-A (or the remote control sensor when it is activated)], which are installed at the suction inlet.
(i) When the operation has been started with cooling, if there is a difference of 2°C or less between the suction and setting
temperatures, the tap of indoor fan is lowered by one tap. This tap is retained for 3 minutes after changing the tap.
(ii) After the above condition, when a difference between suction and setting temperature is lower than 3°C, and the
relative humidity is high, the tap of indoor unit fan is lowered by one tap.
When the difference between suction and setting temperature is larger than 3°C, the fan of indoor unit fan is raised by
one tap. This tap is retained for 3 minutes after changing the tap.
(iii) When relative humidity becomes lower, the indoor unit fan tap is retained.
(iv) In case of the thermostat OFF, the indoor unit fan tap at the thermostat ON is retained.
Room temperature/Cooling
Room temperature/Cooling
30
28
26
Forced thermostat OFF
Forced thermostat OFF
24
22
Forced thermostat
Forced thermostat
OFF
OFF
20
18
16
Heating
Heating
14
12
12 14 16 18 20
14 16 18 20 22
Indoor return air temperature (℃)
Indoor return air temperature (℃)
Cooling
Cooling
Fan
Fan
Thermostat
Thermostat
ON OFF
ON OFF
Í Í
Í Í Í
Í Í
(2)
(2) (2)
Í Í
: Stop / : Turned ON/OFF by the control other than the room temperature control.
/Í: Turned ON/OFF by the control other than the room temperature control.
-
Room temperature/Heating
Room temperature/Heating
Cooling
Cooling
Outdoor temperature/Heating
Outdoor temperature/Cooling
Forced thermostat
Forced thermostat
OFF
OFF
22 24 26 28 30
24 26 28 30
Heating
Heating
Thermostat Thermostat
Thermostat Thermostat
ON OFF
ON OFF
Í
Í
/ /
/Í /Í
(2) / (2)
/Í
(2)
11
-
'19 • PAC-SM-334
Outdoor temperature/Heating
Outdoor temperature/Cooling
Dehumidifying
Dehumidifying
Hot start
Hot start
(Defrost)
(Defrost)
/
/Í
( )
(Í)
Í
( )
(Í) /
/Í
/
/Í /
/Í
Thermostat ON:
Thermostat ON:
Thermostat OFF: Í (2)
Thermostat OFF: (2)