Excessive High Discharge Air Temperature Prevention Control - Hitachi FSXN Series Service Manual

5 Control system
Temperature conditions under defrosting operation:
A: Outdoor evaporating temperature °C.
B: Defrost operation stop area.
C: Outdoor temperature °C.
D: Defrost operation start area.
5.2.9 Excessive high discharge air temperature prevention control (only for RCI, RCD and
RPI (≤ 6 HP))
105
SMGB0065 rev. 1 - 12/2010
Heating Operation
Discharge
Air Temp. of
Indoor Unit
Thermo-OFF
No
Is it continuous
more than 3 min.?
Yes
Discharge Air Temp.
of Indoor Unit
Is setting temp.
No
lower than inlet air temp.
of Indoor Unit?
Yes
Thermo-ON
Thermo ON/OFF Control of Indoor Unit
B
15
10
A
5
-15 -10 -5 5 10 15
0
6
-2
C
-6
-10
D
-15
-21
5