| 摘要 |
PURPOSE: To protect each motor from overload, making use of an electron thermal installed in an inverter, by controlling a plurality of motors not driven at the same time with one inverter. CONSTITUTION: A motor 9 for traveling is connected to the output terminals U, V, and W of an inverter 16 through the normal by open contact MC1a of an electromagnetic contactor MC1, and a motor 11 for drive of a lifter is connected to it through the normal open contact pAC2a an electromagnetic contactor MC2. A truck controller 15 is provided with an exciting and demagnetizing circuit 23 for both electromagnetic contactor MC1 and MC2. CPU 24 installed in the inverter 16 operates the load condition of a motor in ON condition, based on the output signal of a current detection circuit 26, and stops the drive of the motor when it reaches the criteria of overload interruption. CPU 24 judges the ON condition of both motors 9 and 11 from the open and close conditions of the normal open contact MC1a connected between the terminal TH and the terminal S, and outputs a stop command, based on the criteria of overload interruption of the motor in ON condition. |
