Mitsubishi Electric CITY MULTI PUHY-P400YEM-A Service Handbook page 116

Code
Name Product code
(Function)
Solenoid
SV5b heat
vallve
exchanger
capacity
control
SV6
discharge-
suction
bypass
SV7b heat
exchanger
capacity control
(P400,500 only)
SV8b heat
exchanger
capacity control
(P400,500 only)
Linear
SLEV
expansion (Oil return)
valve
L E V 1
( S C coil)
Heater
CH11
CH12
crankcase
heater
CH2
CH3
Accumulator
liquid level
detection
4-way
21S4a
valve
21S4b
Compres-
MC
sor
Pressure
63LS
sensor
Pressure
63H
switch
Thermistor
TH11
(Discharge)
TH3
TH4
(Liquid level
detection)
TH5
(Pipe
temperature)
Application
Controls heat exchanger capacity of
outdoor unit.
Evaporation of liquid refrigerant inside
MC2.
Controls heat exchanger capacity of
outdoor unit.
Controls heat exchanger capacity of
outdoor unit.
Adjusts the rate of refrigerant (oil) re-
turning from the accumulator.
Adjusts the bypass flow rate from the
liquid piping of the outdoor unit during
cooling.
Refrigerant heating inside compressor.
Refrigerant heating of accumulator
liquid level detection circuit.
Switching of cooling/heating cycle.
Controls heat exchanger capacity of
outdoor unit.
When there is a load that cannot be
adjusted by the variable capacity unit,
this function ensures the stable flow of
refrigerant.
1
Detect low-pressure pressure.
2
Perform low-pressure pressure
maintenance.
1
Detects high pressure.
2
Performs high pressure protection.
1
Detects discharge temperature.
2
Performs high pressure protection.
0°C: 698 kΩ 60°C: 48 kΩ
10°C: 413 kΩ 70°C: 34 kΩ
20°C: 250 kΩ 80°C: 24 kΩ
30°C: 160 kΩ 90°C: 17.5 kΩ
40°C: 104 kΩ 100°C: 13.0 kΩ
50°C: 70 kΩ 110°C: 9.8 kΩ
Detects accumulator refrigerant levels
by comparing the temperature
differences between TH9, TH3 and
TH4.
1
Frequency control.
2
Defrost control during heating
operations and liquid level detec-
tion.
3
Detects sub-cool of heat exchanger
outlet using HPS data and TH5 to
control LEV1.
-113-
Specification
AC 220 to 240 V Conductivity test
Close: conducting using tester
Open : not conducting
AC 220 to 240 V
Open : conducting
Close: not conducting
AC 220 to 240 V Conductivity test
Close: not conducting using tester
Open : conducting
AC 220 to 240 V
Open : conducting
Close: not conducting
DC 12 V stepping motor drive Same as indoor unit
valve opening amount 0 to LEV. However, the
480 pulse (Direct drive type). resistance value is
different than the in-
door unit.
Belt heater AC 200 to 240 V Resistance check
1280 Ω 45 W
MC1
MC2 400: 1280 Ω 45 W
500: 1029 Ω 56 W
Code heater 2880 Ω
Resistance check
(1440 Ω + 1440 Ω)
AC 220 to 240 V
20 W (10 W + 10 W)
AC 220 to 240 V Conductivity check
using tester.
Not conducting: cooling cycle
Conducting: heating cycle
Low-pressure shell scroll
type. Winding resistance:
each phase
1.215 Ω (20°C)
8 HP
1.197 Ω (20°C) 10 HP
Pressure
Conductivity check
0 ~ 0.98 MPa
using tester.
Vout 0.5 to 3.5 V
63LS
(0.3 V/MPa)
Con-
Connector
nector
GND (Black)
Vout (White)
Vcc (DC 5 V) (Red)
2.94 MPa OFF setting Conductivity chec k
Resistance check
R = 7.465 kΩ
120
B = 4057
25/120
Rt =
1 1
7.465exp{4057( - )}
273+t 393
Resistance check
R = 15 kΩ
0
B = 3460
1/80
R =
t
1 1
15exp{3460( - )}
273+t 273
0°C: 15 kΩ
10°C: 9.7 kΩ
20°C: 6.4 kΩ
25°C: 5.3 kΩ
30°C: 4.3 kΩ
40°C: 3.1 kΩ
Inspection method
.