Hitachi RAS-2-HVNP Service Manual page 460

11. Electrial checks of main parts
4 If compressor upper part temperature increases excessively the protection control is activated and the compressor is
stopped according to the following method.
Operation
Cooling
Heating
Defrosting
Thermistor for outdoor ambient temperature
The thermistor resistance characteristics are shown in the figure below.
Thermistor for evaporating temperature of outdoor unit in heating operation (for defrosting)
The characteristics for the thermistor is the same with the value of outdoor ambient temperature thermistor as shown in
the figure below.
Thermistor
Resistance
(kΩ)
446
Upper part temperature of compressor
Over 132 ºC
Over 140 ºC
Over 132 ºC
Over 140 ºC
Over 132 ºC
90
80
74
70
60
56
50
43
40
33
30
26
20
10
0
-15 -10 -5 0 5
Ambient and Evaporating Temp. Thermistor Characteristics
SMGB0079 rev.0 - 01/2013
20
16 12.5
10
8
5.3
10 15 20 25 30 35 40
Ambient Temperature ( C)
o
for Outdoor Unit
Defecting period
10 minutes (continuously)
5 seconds (continuously)
10 minutes (continuously)
5 seconds (continuously)
5 seconds (continuously)
3.6
2.5
45 50 55 60