After the diesel generator set is shut down, it is necessary to perform the following tasks: When the diesel generator set is shut down for a long time or for maintenance of the diesel generator set, the negative cable of the starting battery of the generator set must be removed, and the fuel and coolant should be drained if necessary. For self-starting units, some of the above terms are not suitable. The work after the self-starting unit is stopped is to keep it in the state before starting (standby state) in order to prepare for emergency startup.