Various Protections - Fujitsu S24LDC Service Instruction

20. VARIOUS PROTECTIONS

(1). DISCHARGE GAS TEMPERATURE OVERRISE PREVENSION CONTROL
The discharge gas thermosensor (discharge thermistor : Outdoor side) will detect discharge gas
temperature.
When the discharge temperature becomes higher than Temperature ,the compressor frequency
is decreased 20 Hz, and it continues to decrease the frequency for 20 Hz every 120 seconds until
the temperature becomes lower than Temperature .
When the discharge temperature becomes lower than Temperature ,the control of the control of the
compressor frequency is released.
When the discharge temperature becomes higher than Temperature
and the indoor unit LED starts blinking.
(Table 17 : Discharge Temperature Over Rise Prevension Control / Release Temperature)
AS*B24LDC
(2). CURRENT RELEASE CONTROL
The compressor frequency is controlled so that the outdoor unit input current does not exceeds
the current limit velue that was set up with the outdoor temperature.
The compressor frequency returns to the designated frequency of the indoor unit at the time
when the frequency becomes lower than the release value.
(Table 18 : Current Release Operation Value / Release Value)
[ Heating ]
AS*B24LDC
OT (Control / Release)
10.5A / 10.0A
17 C
13.0A / 12.5A
12 C
15.0A / 14.5A
5 C
17.0A / 16.5A
OT : Outdoor Temperature
(3). ANTIFREEZING CONTROL (Cooling and Dry mode)
The compressor frequency is decrease on cooling & dry mode when the indoor heat exchanger
temperature sensor detects the temperature lower than Temperature .
Then, the anti-freezing control is released when it becomes higher than Temperature .
(Table 19 : Anti-freezing Protection Operation / Release Temperature)
Outdoor
AS*B24LDC
Temperature Temperature
104 C
[ Cooling / Dry ]
AS*B24LDC
OT (Control / Release)
7.0A / 6.5A
46 C
9.5A / 9.0A
40 C
11.5A / 11.0A
Temperature
Temperature
4 C
Over than 12 C
4 C
Less than 12 C
Temperature
101 C 110 C
Temperature
7 C
13 C
05-18
,the compressor is stopped