Mitsubishi Electric HP120TNU-A Service Handbook page 82

[3-3 Functions of the Major Components of Outdoor Unit ]
Part Symbols
name (functions)
Thermis- TH3
tor (Pipe
temperature)
TH7
(Outdoor tem-
perature)
TH5
(Pipe tempera-
ture)
TH15
(Compressor
shell bottom
temperature)
THHS
Inverter
heat sink tem-
perature
THL DCL tem-
perature
Sole- SV1a
noid Discharge-suc-
valve tion
bypass
SV2
LEV LEV2a, 2b
LEV2d
LEV9
4-way 21S4a, b
valve
HWE18220_GB
Notes Usage
Controls defrosting during heating
operation
1) Detects outdoor air tempera-
ture
2) Controls fan operation
Fan operated on the 63LS and
TH5 values.
Detects compressor shell bottom
temperature
Inverter overheating protection
DCL overheat protection
1) High/low pressure bypass at
start-up and stopping, and
capacity control during low-
load operation
2) High-pressure-rise preven-
tion
Prevention of low-pressure drop
Refrigerant equalization control
(During cooling)
Heat exchanger capacity control
(During heating)
Refrigerant equalization control
Heat exchanger capacity control
Refrigerant cooling control
Changeover between heating and
cooling
Specifications
Degrees Celsius
R = 15k
0
R = 3460
0/80
1 1
R = 15 exp
3460
t
273
0°C[32°F] :15 k
10°C[50°F] :9.7 k
20°C[68°F] :6.4 k
25°C[77°F] :5.3 k
30°C[86°F] :4.3 k
40°C[104°F] :3.1 k
Degrees Celsius
R = 17k
50
R = 4016
25/120
1 1
exp
R = 17
4016
t
323
0°C[32°F] :161 k
10°C[50°F] :97 k
20°C[68°F] :60 k
25°C[77°F] :48 k
30°C[86°F] :39 k
40°C[104°F] :25 k
Degrees Celsius
R = 3.3k
100
B = 3970
0/100
1 1
R =3.3 exp
3970
t
373
0°C[32°F] :162.2 k
10°C[50°F] :98.3 k
25°C[77°F] :49.1 k
50°C[122°F] :17.6 k
100°C[212°F] :3.3 k
AC208 - 230V
Open while being powered/
closed while not being pow-
ered
AC208 - 230V
Open while being powered/
closed while not being pow-
ered
DC12V
Opening of stepping motor
driving valve 0-3000 pulses
(LEV2a, 2b)
0-6000 pulses
(LEV2d, HP72-120)
DC12V
Opening of stepping motor
driving valve 0-480 pulses
(direct driven type)
AC208 - 230V
Dead: cooling cycle
Live: heating cycle
Check method
Resistance check
Continuity check
with a tester
Continuity Test
with a Tester.
Continuity be-
tween white and
orange.Continu-
ity between yel-
low, brown, and
blue
White
M
Orange
Yellow Brown Blue
Continuity check
with a tester
5
chapter 3 -