Komatsu PC88MR-10 Shop Manual page 276

10 Structure and function
Electrical control system
System operating lamp function
1. Battery disconnect switch
2. Battery
3. System operating lamp
4. Machine monitor
5. Engine controller
6. Pump controller
7. KOMTRAX terminal
Function
You can prevent an abnormal end due to cut-off of the battery power supply circuit while the controllers are
in operation by checking the operating status of machine monitor (4), controllers (5), (6), and (7) with
system operating lamp (3).
a Before cutting off the battery power supply circuit, turn the starting switch to "OFF" position, and check that
system operating lamp (3) goes off, then turn battery disconnect switch (1) to "OFF" position.
a If you turn battery disconnect switch (1) to "OFF" position (battery power supply circuit is cut off) while
system operating lamp (3) is ON, data lost error of machine monitor (4), controllers (5), (6), and (7) can
occur. Do not operate battery disconnect switch (1) while system operating lamp (3) is ON.
a System operating lamp (3) goes off in 2 minutes after the starting switch is turned to "OFF" position.
a System operating lamp (3) may sometimes light up while the starting switch is turned to "OFF" position
because KOMTRAX terminal (7) may maintain its communication under this condition.
ON/OFF of system operating lamp
Voltage of 24 V is always applied to one end of the system operating lamp (LED) (3).
When any of machine monitor (4), controllers (5), (6), and (7) is in operation, the controller outputs low
voltage (0 V), and a current flows in the diode to turn ON system operating lamp (3).
When all of machine monitor (4), controllers (5), (6), and (7) are stopped, the controller outputs high
voltage (24 V), and no current flows in the diode, thus system operating lamp (3) goes off.
a System operating lamp (3) may look slightly luminous in the dark after it is turned off. It is due to the minute
leakage of current and not an abnormal phenomenon.
KOMTRAX terminal (7) performs communication periodically even if the starting switch is kept in "OFF"
position, thus it starts and stops repeatedly.
The start and stop cycle (sleep cycle) of KOMTRAX terminal (7) varies the conditions including the
communication status and machine stop time, and the lamp may keep lighting for up to approximately one
hour
a When you want to cut off the battery circuit for maintenance but system operating lamp (3) keeps on
lighting up, turn the starting switch to ON position, and then turn it to OFF position, and the lamp goes off
in 2 minutes.
After system operating lamp (3) goes off, turn battery disconnect switch (1) immediately to "OFF" position.
10-198
(PC138-AW1Q-042-K-00-A)
PC88MR-10