Mitsubishi Electric CAHV-R450YA-HPB Service Manual page 84

[ VI Refrigerant Circuit ]
Part Symbols
name (functions)
Thermi TH2
stor (Suction)
TH3
(Compressor
shell tempera-
ture)
TH4
(Air HEX Ref.
temperature)
TH9
(Outdoor
temperature)
TH10
(Water inlet)
TH11
(water outlet)
TH21
(Water heat ex-
changer)
4-way 21S4a
valve 21S4b
Fan FAN motor
motor
Linear LEV2
expan- (INJ control)
sion
valve
LEV1
LEV3
(Refrigerant
flow adjust-
ment)
HWE22020
Notes Usage
Detects low pressure drop
Controls defrosting during
heating operation
1) Detects low pressure drop
2) Controls defrosting during
heating operation
1) Detects outdoor air tem-
perature
2) Controls fan operation
Controls compressor opera-
tion
Controls compressor opera-
tion
Detects water heat exchanger
temperature
Changeover between heating
and defrost
Regulates the heat exchanger
capacity by adjusting the oper-
ating frequency and operating
the propeller fan based on the
operating pressure.
Adjusts the amount of bypass
flow from the liquid pipe on the
outdoor unit during heating
Adjusts refrigerant flow during
heating
Specifications
Degrees Celsius
R = 15kohm
0
R = 3385
0/80
R = 15 exp
3385
t
0°C[32°F] :15kohm
10°C[50°F] :9.7kohm
20°C[68°F] :6.5kohm
25°C[77°F] :5.3kohm
30°C[86°F] :4.4kohm
40°C[104°F] :3.0kohm
AC220-240V
OFF: defrost cycle
ON: heating cycle
AC400V, 920W
DC12V
Opening of a valve driven
by a stepping motor 0-480
pulses (direct driven type)
DC12V
Opening of a valve driven
by a stepping motor 2000
pulses (LEV1)
Opening of a valve driven
by a stepping motor 3000
pulses (LEV3)
- 75 -
Check method
Resistance check
1 1
273
Continuity check with a
tester
Refer to the section
"Continuity Test with a
Tester".
Continuity between
white, yellow, and
orange.
Continuity between
blue, brown, and red.
Refer to the section
"Continuity Test with a
Tester".
Continuity between
white, red, and orange.
Continuity between yel-
low and blue.
White
Red
Orange
Yellow
M
Blue
GB