Komatsu PC200-8M0 Shop Manual page 1183

100 Air conditioner
System diagram
Input and output signals of the air conditioner
controller
Controller connector: AMP 025 - 32PM
Wiring harness connector:
32PF)
AMP025 - 32PF
Pin
Symbol
No.
1 +Bback Backup power supply
2 – (*1)
3 SS Sunlight sensor
4 THOUT Outside air temperature sensor Input
Evaporator temperature sen-
5 THF
sor
6 THI Inside air temperature sensor
Servomotor potentiometer
7 POT5 V
power supply (5 V)
8 BWFB Blower feedback signal
9 PTRB Power transistor control signal Output
10 CAN_H CAN communication signal (H)
11 CAN_L CAN communication signal (L)
12 – (*1)
Fresh/recirculated air servomo-
13 MRFA
tor terminal A
Fresh/recirculated air servomo-
14 MRFB
tor terminal B
15 MAMA Air mix servomotor terminal A
16 MAMB Air mix servomotor terminal B
17 +24 V 24 V power supply
18 – (*1)
Air mix servomotor potentiom-
19 SAM
eter signal
Vent (mode) changeover ser-
20 SVI
vomotor potentiometer signal
PRESS
21 Dual pressure switch
SW
22 – (*1)
23 – (*1)
24 – (*1)
25 GNDS Sensor GND
26 GND GND
27 – (*1)
28 – (*1)
29 RLCC Compressor clutch relay
30 – (*1)
Vent (mode) changeover ser-
31 MV1A
vomotor terminal A
Vent (mode) changeover ser-
32 MV1B
vomotor terminal B
*1: Never connect these pins. Malfunctions or fail-
ures may occur.
PC200, 200LC, 220, 220LC-8M0
ACECU (AMP025 -
Input/
Out-
Signal name
put
signal
Input
Input
Input
Input
Output
Input
Input/o
utput
Input/o
utput
Output
Output
Output
Output
Input
Input
Input
Input
Input
Input
Output
Output
Output
Operation of air conditioner controller
q
1. Performing
machine monitor, the air conditioner controller
controls the air conditioner unit by inputting
switches associated with air conditioning.
2. The air conditioner controller controls three
servomotors located inside the air conditioner
unit in order to adjust the temperature (airmix),
perform vent (mode) changeover, and perform
FRESH/RECIRC air changeover.
3. The air conditioner controller controls the
– ON/OFF condition of the compressor clutch
relay (i.e.,
compressor).
4. The air conditioner controller controls the air flow
volume using the power transistor.
a The power transistor has an overcurrent pre-
vention fuse in it.
5. The air conditioner controller detects the evapo-
rator temperature using the evaporator tempera-
ture sensor.
6. In order to prevent freezing of the evaporator,
the air conditioner controller controls the
compressor by turning the compressor clutch
relay ON and OFF.
–
a When the dual pressure switch detects a
pressure abnormality (i.e., turns OFF), the air
conditioner controller turns the compressor
clutch relay OFF, and therefore, the com-
pressor stops operating.
7. When performing automatic air conditioning, the
air conditioner controller controls the inside (air)
–
temperature to the set temperature and adjust
the air flow according to the data from the
sunlight sensor, the outside air temperature
sensor, and the inside air temperature sensor.
8. The air conditioner controller has the self-diag-
nosis function. If any abnormality is detected, the
– controller notifies it to the machine monitor by
– the CAN communication. Then, failure code
– [879***] is displayed on the "Electrical Systems"
screen of the electrical system on the machine
monitor.
–
–
–
SEN06151-00
CAN communication
a switch for activating
80-100
with the
the
25