Nobu NBFS-48IDU Service Manual page 27

1
10° C
0° C
-15° C
compressor
outdoor
blower fan
indoor
blower fan
four-way
valve
Heating (only applicable to dual temperature units)
● Start up the compressor: when the room temperature is less than or equal to Ts-1 ℃ , compressor →
start-up
● Shut down the compressor: when the room temperature is more than or equal to the set temperature Ts+1 ℃ ,
compressor → shutdown
● The electric heating start-up in the heating mode shall meet the following conditions: ① start up the
compressor for three minutes and indoor blower fan ② Tr ≤ Ts － 3 ℃ ③ TP1< 46 ℃ ④ Tr ≤ 23 ℃ .
● The electric heating shutdown in the heating mode shall meet one of the following conditions: ①
shutdown the indoor blower fan ② Tr ≥ 26 ℃ ③ TP1 ≥ 50 ℃ ④ change mode.
● When the temperature of coil pipe of indoor units is more than or equal to 56 ℃ , the outdoor blower fan
shuts down and it enters the overload protection; when the temperature of coil pipe of indoor units is less
than or equal to 52 ℃ , the outdoor blower fan starts up and it exit the overload protection.
● When the temperature of coil pipe of indoor units rises to 65 ℃ , the compressor and outdoor blower fan are
closed and two minutes later, the change valve is closed. The indoor blower fan is running at the set speed.
Restart up six minutes later; if the above situations appear again within ten minutes, all the outputs are shut
down through the electric control board and the display failure.
Tr