Various Protections - Fujitsu AB 14LBAJ Series Service Instruction

21. VARIOUS PROTECTIONS

1. DISCHARGE GAS TEMPERATURE OVER RISE PREVENTION CONTROL
The discharge gas thermosensor (discharge thermistor : Outdoor side) will detect discharge gas
temperature.
When the discharge temperature becomes higher than
is decreased 10 Hz, and it continues to decrease the frequency for 10 Hz every 120 seconds until
the temperature becomes lower than
When the discharge temperature becomes lower than
frequency is released.
When the discharge temperature becomes higher than
When the discharge temperature becomes lower than
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.
3. ANTI-FREEZING CONTROL (Cooling mode)
The compressor frequency decreases on cooling mode when the indoor heat exchanger
temperature sensor detects the temperature lower than
Then, the anti-freezing control is released when it becomes higher than
(Fig 13 : Anti-freezing Protection Operation / Release Temperature)
Indoor heat exchange
temperature
3°C
6°C
12°C
110°C .
The compressor frequency is
decreased 10Hz every 120 seconds.
Hold
Compressor OFF : Hold
Compressor ON : Release of protection
Release of protection
01-33
110°C ,the compressor frequency
105°C ,the control of the compressor
120°C ,the compressor stops.
80°C ,the compressor operates.
3°C.
6°C.