| 摘要 |
PROBLEM TO BE SOLVED: To avoid the impossibility of excavation starting attributable to the voltage drop of a generator when an electric motor is subjected to an excessive load. SOLUTION: This ground excavator is provided with a rotary drive means 5 having an electric motor which drives an excavation shaft 4 turningly, an electromagnetic contactor 9 which controls the drive of the rotary drive means 5 and a controller 10 which controls the on/off operation of the electromagnetic contactor 9 so that electric power may be supplied to the drive means 5 from a generator 8 by way of the electromagnetic contactor 9 while the power from the generator is partially distributed to the controller 10 as the electric power required for the on/off operation of the electromagnetic contactor 9. In this case, a non-power failure device 20 is provided on a line where the power from the generator is partially supplied to the controller 10. |
