Mitsubishi Electric CITY MULTI PUHY-400YMF-C Service Handbook page 115

Code
Name Product code
(Function)
Thermistor TH3
TH4
(Liquid level
detection)
TH5
(Liquid pipe
temperature)
TH6
(Outdoor
temperature)
TH7
TH8
TH9a
(SC control)
TH9b
(P400,
P500 only)
TH10a
TH10b
Heat
exchanger
Gas tempera-
ture
TH10c
(P400,
P500 only)
THHS inverter
heat sink tem-
perature
Solenoid
SV1
valve
discharge-
suction
bypass
SV22
capacity
control (full
load)
SV32
capacity
control
(unload)
SV4
discharge-
suction
bypass
Application
Detects liquid level of refrigerant inside
accumulator using the differences
among TH2, TH3, TH4.
1 Frequency control.
2 Controls defrosting during heating.
1
Detects the outdoor air temperature.
2
Performs fan control, liquid level
heater control, opening settings of
LEV for oil return and other functions.
Controls LEV using temperature
differences among TH5, TH7, TH8
and TH9a.
1) Detects the CS circuit fluid tempera-
ture.
2) Calculates the refrigerant circulation
configuration.
Performs constant capacity unit LEV2
control by comparing the temperature
difference with low pressure saturation
temperature.
1) Detects the compressor shell
temperature.
2) Provides compressor shell over-
heating protection.
Inverter cooling fan control using THHS
temperature.
1 Capacity control of high/low
pressure bypass when starting and
stopping.
2 Discharge pressure rise suppression.
Switching of capacity control valve inside
No. 2 compressor (Switching between
full load operation and unload operation)
(All but 400).
Capacity control and controlling the rise
of high-pressure (Back-up of frequency
control).
-112-
Specification
R = 15 kΩ
0
B = 3460
1/80
Rt =
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
R = 15 kΩ
0
B = 3460
1/80
Rt =
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
R = 7.465 kΩ
120
B = 4057
25/120
Rt =
7.465exp
1 1
{4057( - )}
273+t 273+120
20°C: 250 kΩ 70°C: 34 kΩ
30°C: 160 kΩ 80°C: 24 kΩ
40°C: 104 kΩ 90°C: 17.5 kΩ
50°C: 70 kΩ 100°C: 13.0 kΩ
60°C: 48 kΩ 110°C: 9.8 kΩ
R = 17 kΩ
50
B = 4170
25/120
Rt =
1 1
17exp {4170 ( - )}
273+t 323
0°C: 181 kΩ
10°C: 105 kΩ
20°C: 64 kΩ
25°C: 50 kΩ
30°C: 40 kΩ
40°C: 26 kΩ
AC 220 to 240 V
Open : conducting
Close: not conducting
AC 220 to 240 V
Close: conducting
Open : not conducting
AC 220 to 240 V
Open : conducting
Close: not conducting
Inspection method
Resistance check
Resistance check
Resistance check
Conductivity test
using tester