
[3-4 Functions of the Major Components of Indoor Unit ]
HWE18240_GB
chapter 3 -
7
3 Major Components, Their Fu
nctions and Refrigerant Circuits
3-4
Functions of the Major Components of Indoor Unit
Part
Name
Symbol
(functions)
Notes Usage
Specification Check
method
Linear
expan-
sion valve
LEV
1) Adjusts superheat at the
indoor heat exchanger
outlet during cooling
2) Adjusts subcool at the in-
door unit heat exchanger
outlet during heating
DC12V
Opening of stepping motor
driving valve 0-(1800) pulses
Continuity Test with a
Tester.
Continuity between
white, red, and or-
ange.
Continuity between
yellow, brown, and
blue.
Thermis-
tor
TH1
(Suction air tem-
perature)
Indoor unit control (Thermo)
0°C [32°F]:15 k
ȍ
10°C [50°F] :9.7 k
ȍ
20°C [68°F]:6.4 k
ȍ
25°C [77°F] :5.3 k
ȍ
30°C [86°F] :4.3 k
ȍ
40°C [104°F] :3.1 k
ȍ
Resistance check
TH2
(Pipe tempera-
ture)
1) Indoor unit control (Frost
prevention, Hot adjust)
2) LEV control during heat-
ing operation (subcool
detection).
TH3
(Gas pipe tem-
perature)
LEV control during cooling op-
eration (superheat detection)
TH4
Outdoor air tem-
perature)
Indoor unit control (Thermo)
Temperature
sensor (Indoor
air temperature)
Indoor unit control (Thermo)
Yellow
White
Red
Orange
Brown Blue
M
1
273+t
R
0
=15k
R
0/80
=3460
Rt =
15exp{3460( - )}
1
273
Summary of Contents for PUHY-HP120TNU-A
Page 1: ......
Page 11: ...HWE18240_GB ...
Page 27: ...HWE18240_GB ...
Page 59: ...HWE18240_GB ...
Page 69: ...HWE18240_GB ...
Page 87: ...HWE18240_GB ...
Page 109: ... 5 2 Outdoor Unit Control 22 chapter 5 HWE18240_GB 5 Control ...
Page 111: ...HWE18240_GB ...
Page 121: ...HWE18240_GB ...
Page 279: ...HWE18240_GB ...
Page 297: ...HWE18240_GB ...
Page 324: ......