Capacity Control; Auto Changeover Operation - Fujitsu ARU7RLF Service Instruction

1. CAPACITY CONTROL

1-1 COOLING, HEATING, DRY CAPACITY CONTROL
Compressor frequency decides by capacity of an indoor unit, operation number of an indoor unit,
set temperature, room temperature and outside temperature.

2. AUTO CHANGEOVER OPERATION

When the air conditioner is set to the Auto mode by remote controller, operation starts in the optimum
mode from among the Heating, Cooling, Dry and Monitoring mode. During operation, the
optimum mode is automatically switched in accordance with temperature changes. The temperature
can be set between 64°F(18°C) and 88°F(30°C) in 2°F(1°C) steps.
When operation starts, indoor fan and outdoor fan are operated for around 3 minutes.
1
Room temperature and outdoor temperature are sensed,
and the operation mode is selected in accordance with the table below. <Monitoring mode>
( Table 1 : Operation mode selection table )
Room temperature (TR)
TR> Ts+4°F(+2°C)
Ts+4°F(+2°C)
TR < Ts -4°F(-2°C)
*
If it's Middle zone, operation mode of indoor unit is selected as below.
(1). Same operation mode is selected as outdoor unit.
If outdoor unit is operating in Cooling, Dry, and Heating mode,
indoor unit will be operated by the same operation mode.
(2). Selected by the outdoor temperature.
If outdoor unit is operating in other than Cooling, Dry, and Heating mode,
indoor unit will be operated according to the outdoor temperature as below.
( Fig. 1 : Outdoor temperature zone selection )
77°F (25°C)
2 When Cooling or Dry mode was selected at
The same operation as COOLING OPERATION AND DRY OPERATION.
When the room temperature has remained at set temperature -3°F(-1.5°C),
operation is automatically switched to Dry mode.
If the room temperature reaches set temperature +4°F(+2°C) during Dry mode, operation returns to Cooling.
( Fig.2 : Auto changeover : Cooling - Dry )
( Air flow mode : Auto )
Ts +2°F(+1°C)
Ts -3°F(-1.5°C)
Ts -5°F(-2.5°C)
When the room
temperature drops
Operation mode
(Autmatic dry)
TR Ts -4°F(-2°C)
Cooling mode
Heating mode
1
Cooling
Dry(X zone)
Cooling
Dry(J zone)
Compressor stop
Cooling
*
Middle zone
Heating
and air flow mode is Auto, the air conditioner operates as follow.
Ts +4°F(+2°C)
Ts -1°F(-0.5°C)
Ts -3°F(-1.5°C)
When the room
temperature rises
01-01
TR : Room temperature
Ts : Setting temperature
TR : Room temperature
Ts : Setting temperature