Mitsubishi Electric PUHY-HP72 Service Handbook page 65

[3-3 Functions of the Major Components of Outdoor Unit ]
Part Symbols
Notes
name (functions)
Sole- SV1a
noid Discharge-
valve suction
bypass
SV2
SV9
SV10
Linear LEV1
expan- (SC control)
sion
valve
LEV9
(Refrigerant
flow adjust-
ment)
LEV4
(Refrigerant
flow adjust-
ment)
LEV2a
(Refrigerant
flow adjust-
ment)
LEV2b
(Refrigerant
flow adjust-
ment)
4-way 21S4a
valve
21S4b
Fan FAN motor
motor 1,2
6
- chapter 3
Usage
1) High/low pressure bypass at
start-up and stopping, and
capacity control during low-
load operation
2) High-pressure-rise preven-
tion
Makes excessive refrigerant in the
accumulator evaporate
High-pressure-rise prevention
Continuous heating cycle mode
Adjusts the amount of bypass flow
from the liquid pipe on the outdoor
unit during cooling
Adjusts the flow of refrigerant by-
passed from the pipe for cooling
the control board when the control
board temperature rises
Controls the bypassed refrigerant
flow to the compressor to sup-
press rises in the discharge tem-
perature (TH4).
Adjusts refrigerant flow during
heating
Cut off the refrigerant flow during
continuous heating cycle
Changeover between heating and
cooling
1) Changeover between heating
and cooling
2) Controls outdoor unit heat ex-
changer capacity
Regulates the heat exchanger ca-
pacity by adjusting the operating
frequency and operating the pro-
peller fan based on the operating
pressure.
Specifications
AC208-230V
Open while being powered/
closed while not being pow-
ered
Open while being powered/
closed while not being pow-
ered
Open while being powered/
closed while not being pow-
ered
Open while being powered/
closed while not being pow-
ered
DC12V
Opening of a valve driven by a
stepping motor 0-480 pulses
DC12V
Opening of a valve driven by a
stepping motor 2100 pulses
(Max. 3000 pulses)
AC208-230V
Dead: cooling cycle
Live: heating cycle
AC208-230V
Dead: cooling cycle
Outdoor unit heat exchanger
capacity at 100%
Live: heating cycle
Outdoor unit heat exchanger
capacity at 25%, 50%
or heating cycle
AC380-460V, 460W (YNU)
AC200-230V, 460W (TNU)
Check method
Continuity check
with a tester
Same as indoor
LEV
The resistance val-
ue differs from that
of the indoor LEV.
Refer to the follow-
ing page(s). [8-8
Troubleshooting
LEV Problems]
Continuity Test with
a Tester.
Continuity between
white and orange.
Continuity between
yellow, red, and
blue.
White
M
Orange
Yellow red Blue
Continuity check
with a tester
HWE18240_GB