Capacity Control; Auto Changeover Operation - Fujitsu ASU18RMLQ 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

2-1 For AS, AU type
When the air conditioner is set to the AUTO mode by remote control, operation starts in the optimum
mode from among the HEATING, COOLING, DRY and MONITORING modes. 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, only the indoor and outdoor fans are operated for 1 minute. After 1 minute,
1
the room temperature and outside air temperature are sensed and the operation mode is
selected in accordance with the table below.
( Fig.1 : Outside air temperature zone selection )
C zone
90°F(32°C)
B zone
32°F(0°C)
A zone
( Table.1 Operation mode selection table)
Outside air temperature (TO)
Room temperature (TB)
TB > TS+4°F(2°C)
TS+4°F(2°C) TB
TB TS- 4°F(2°C)
2
.When COOING was selected at
The same operation as COOLING OPERATION of item 1 above is performed.
When the room temperature has remained at (set temperature -2°F(1°C)) for 8 minutes, operation is
automatically switched to DRY and the same operation as DRY OPERATION of item 3 above
is performed.
If the room temperature reaches (set temperature +4°F(2°C) during DRY operation, operation returns to
COOLING operation.
3 .When HEATING was selected at
above is performed.
4 When the compressor was stopped for 6 consecutive minutes by the temperature control function
after the COOLING or HEATING operation mode was selected at
to MONITORING and the operation mode is selected again.
TS - 4°F(2°C)
<
1 , the air conditioner operates as follow:
, the same operation as HEATING OPERATION of item 2
1
01-01
A zone B zone
Cooling
Monitoring
(automatic dry)
Monitoring Monitoring
Heating Heating
above, operation is switched
1
C zone
Cooling
(automatic dry)
Monitoring
Monitoring