Basic Mode - Hitachi RAS-S24H2A Service Manual

(ON OFF TIMER DURING OPERATION) (OFF ON TIMER DURING STOP)
Med
Operating mode
Operating mode is judged by room temperature and outdoor temperature
1. Judging by outdoor temperature
• Operating mode is judged by outdoor temperature
If outdoor temperature ≥ 25°C or 21°C ≤ outdoor temperature
(i)
< 25°C : restricted to cooling.
(ii) If outdoor temperature <18°C or 18°C ≤ outdoor temperature
< 21°C : restricted to heating.
(iii) If 21°C ≤ outdoor temperature < 25°C or 18°C ≤ outdoor
temperature < 21°C : restricted to dehumidifying.
2. Judging by room temperature
(a) Condition for judgement (any of followings)
• When auto operation is started after 1 hour elapsed since the
operation was stopped.
• When auto operation is started after the previous manual mode
operation.
• When the operating mode is switched to auto while operating
at manual mode.
(b) Operating mode is judged by room temperature.
Room temperature > 27°C ± 3°C : cooling.
(i)
(ii) Room temperature ≤ 23°C ± 3°C : heating.
(iii) Room temperature or room temperature > 23°C :
dehumidifying.
* ±3°C is the shift value, can be set by remote controller.
Judging operating mode change during operation (continuous judgement)
(a) Condition for judgement (any of followings)
KAFON
• The mode is reviewed at every internal time.
KAFOF
• When auto operation is started again before 1 hour has elapsed
since the operation was stopped.
(b) Judging method
• Judge by setting the hysterisis on the final preset temperature, the
final preset temperature is the actually targeted preset temperature
heating
which is the sum of basic preset temperature and each type of shift
value (eg: shift value by remote controller, preset temperature
correction value, powerful shift value, etc).
[CURRENTLY COOLING]
• Room temperature ≤ final preset temperature -3°C change to heating
• Room temperature > final preset temperature - 3°C continue to cooling
[CURRENTLY HEATING]
• Room temperature ≥ final preset temperature +2°C change to cooling.
• Room temperature < final preset temperature +2°C continue heating.
Cooling
Heating
– 39 –