S7-200 AC power supply boundaries and I/O boundaries to AC circuits are rated 1500 VAC. These isolation boundaries have been examined and approved as providing safe separation between AC line and low voltage circuits.我的翻译是：S7-200电源范围及交流I/O回路电压范围被定为 1500VAC。作为给出的交流线路和低压回路之间的安全距离，这些绝缘界限已经被检验和认可。All low voltage circuits connected to an S7-200, such as 24V power, must be supplied from an approved source that provides safe isolation from AC line and other high voltages.我的翻译：所有连接到一个S7-200低压回路，如24V电源，必须由一个经过认可的电源供应，此电源的交流线路和其他高压线路是安全绝缘的。翻译不知对错，请高手指正。