If mains power is used, the workpiece must be positively earthed using a well-protected earthing wire connected at both ends by bolted lugs or secure screw clamps.

• 采用电网电源时，必须采用受到良好保护的接地线（其两端均采用螺栓固定的突耳或紧固螺丝夹连接）将工件可靠地接地。