Mitsubishi Electric PUHY-P200 Service Handbook page 65

Symbol
Name
(function)
Solenoid SV1
valve Discharge-
suction bypass
SV3
P450-P650
Discharge-
types only
suction bypass
SV5b
Heat exchanger
capacity control
SV5c P400-P650
Heat exchanger types only
capacity control
Linear
LEV1
expansion
(SC coil)
valve
Heater CH11, 12
CH12 on
Crankcase P450-P650
heater
types only
4-way
21S4a
valve
21S4b
21S4c
P400-P650
types only
2. Indoor Unit
Symbol
Name
(function)
Linear LEV
expansion
valve
Thermistor
TH1 (Suction air
temperature)
TH2 (Piping
temperature)
TH3 (Gas-side
piping
temperature)
TH4 (Outdoor air
temperature)
Temperature
sensor (Indoor
air temperature)
Notes Function
1 High/low pressure bypass at
starting and stopping, and capacity
control during low-load operation
2 High-pressure rise suppression
Provides compressor protection
when Compressor No. 2 is at a stop
Controls outdoor unit heat exchanger
capacity.
Adjusts the volume of bypass flow
from the outdoor unit during cooling
operation.
Heats refrigerants in the compressor.
Switches between cooling and heat-
ing cycles.
Switches between cooling and heat-
ing cycles.
Controls outdoor unit heat exchanger
capacity.
Switches between cooling and heat-
ing cycles.
Controls outdoor unit heat exchanger
capacity.
Notes Function
1 Adjusts superheat at the indoor
heat exchanger outlet during
cooling
2 Adjusts subcool at the indoor heat
exchanger outlet during cooling
Indoor unit control (Thermo)
1 Indoor unit control (Anti-
freeze/heat adjustment)
2 LEV control during heating
operation (subcool detection)
LEV control during cooling operation
(superheat detection)
Indoor unit control (Thermo)
Indoor unit control (Thermo)
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Specification
AC220~240V
Open when energized
Closed when not energized
AC220~240V
Closed when energized
Open when not energized
DC12V
Opening of stepping motor
driving valve 0-480 pulses
(direct driven type)
Cord heater AC220~240V
CH11,CH12·····1280Ω 45W
AC220~240V
De-energized : cooling cycle
Energized : heating cycle
AC220~240V
De-energized : cooling cycle
(Outdoor unit heat exchanger capacity 100%)
Energized : cooling cycle
(Outdoor unit heat exchanger capacity 50%)
or heating cycle
AC220~240V
De-energized : cooling cycle
(Outdoor unit heat exchanger capacity 100%)
Energized : cooling cycle
(Outdoor unit heat exchanger capacity 25%)
or heating cycle
Specification
DC12V
Opening of stepping motor
driving valve 0-1400 pulses
R =15kΩ
0
R =3460
0/80
Rt =
1 1
15exp{3460( - )}
273+t 273
0˚C : 15kΩ 30˚C : 4.3kΩ
10˚C : 9.7kΩ 40˚C : 3.1kΩ
20˚C : 6.4kΩ
25˚C : 5.3kΩ
Check method
Continuity check
with a tester
Same as indoor LEV.
The resistance value
is not the same as
that of the indoor LEV.
(Refer to the section
on LEV troubleshoot-
ing.)
Resistance value
check
Continuity check
with a tester
Check method
Refer to the section
on continuity test
with a tester
Continuity between
white-red-orange
Continuity between
yellow-brown-blue
White
M
Red
Orange Yellow Brown Blue
Resistance value
check