Komatsu PC88MR-10 Shop Manual page 278

10 Structure and function
Electrical control system
Function
Usually, battery disconnect switch (1) is used instead of disconnecting the cable from the negative
terminal of the battery in the following cases.
1. When storing the machine for a long period (more than 1 month)
2. When servicing or repairing the electrical system
3. When performing electric welding
4. When handling the battery
5. When replacing the fuse, etc.
When battery disconnect switch (1) is turned to OFF position (the contact is opened), all the continuous
power supplies for the components, including the starting switch B terminal and controllers, are all cut out,
and the condition is the same as the condition when the battery is not connected. Accordingly, all of the
electrical system of the machine does not operate.
System operating lamp (2) lights up while the controller is in operation. It lights up when KOMTRAX
terminal is performing communication, even if the starting switch is set to OFF position.
Precautions for using battery disconnect switch
Do not turn OFF battery disconnect switch (1) while system operating lamp (2) is lit.
If battery disconnect switch (1) is turned OFF while system operating lamp (2) is lit, the data in the
controller may be lost and the controller may be damaged seriously.
Do not turn OFF battery disconnect switch (1) while the engine is running or immediately after the engine
is stopped.
If battery disconnect switch (1) is turned OFF while the alternator is generating power, the generated
current has nowhere to go, leading to overvoltage in the electrical system of the machine, which may
cause serious damage to the electrical system, including the electric devices and controllers.
If battery disconnect switch (1) is turned OFF for a long period, the machine monitor and the clock of the
radio may be initialized. In this case, re-setting is required.
10-200 PC88MR-10