Pcb Function - Nobu NBFS-48IDU Service Manual

6.

PCB function:

NOTE: Ts is the set temperature, Tr is indoor room temperature, TP1 is indoor coil pipe temperature, TP2 is
outdoor coil pipe temperature.
Cooling
● Start up the compressor: when the room temperature is more than or equal to Ts+1 ℃ , compressor →
start-up
● Shut down the compressor: when the room temperature is equal to or less than the set temperature Ts-1 ℃ ,
compressor → shutdown
● When the temperature of coil pipe of the indoor units is less than or equal to 0 ℃ and the compressor has
continuous run for more than ten minutes, the compressor and outdoor blower fan shut down through the
electric control board and the indoor blower fan is running at set speed.
● When the temperature of coil pipe of the indoor units is more than 10 ℃ or room temperature less than or
equal to set temperature and the compressor has shutdown for more than three minutes, the compressor and
outdoor blower fan start to run and the indoor blower fan is running at set speed.
● When the temperature of coil pipe of the indoor units is equal to or less than － 15 ℃ for three minutes in
the compressor has continuous run for six minutes, the compressor, indoor and outdoor blower fans and
swinging wind shut down. Restart up six minutes later; if the above situations appear again within six
minutes, all the outputs are shut down through the electric control board and the display failure.