ABB TB850 CEX 总线终端（针式） TB850 3BSC950193R1

ABB TB850 CEX 总线终端（针式） TB850 3BSC950193R1

接地螺丝因机柜本体与底座间有胶皮形成绝缘，屏蔽地汇流排与底座间绝缘，现场控制站按规定做好接地处理。即分别接至现场控制站接地汇流排上。

I/O柜的电源地与UPS的电源地接至同一个地，保证等电位。

2.各个硬件设备操作员站、工程师站、网络交换机、服务器主机、系统显示器等采用外壳接地或直接将电源地线连接至电气接地网。

3.I/O组件模拟量模件的40端即直流24伏的负端接至逻辑地汇流排上，逻辑地汇流排接至屏蔽地，再接入总接地汇流排。

4.屏蔽地现场控制站的保护地应从机柜下方的接地螺钉接至接地分干线,现场控制站的屏蔽地应从接地汇流排接至公共连接板。

5.接地电阻测试接地系统的电阻进行测试，以保证接地能满足控制系统制造商的要求。

用电仪表的外壳、仪表盘、柜、箱、盒和电缆槽 、保护管、支架、底座等正常不带电的金属部分，由于绝缘破坏而有可能带危险电压者，均应做保护接地。对于供电电压不高于36V的就地仪表、开关等，当设计文件无特殊要求时，可不做保护接地。

The ground screws are insulated between the cabinet body and the base by rubber sheets. The shielded ground bus is insulated from the base. The onsite control station should ground the cables according to regulations. That is, connect it to the ground bus bar of the field control station.

The power supply ground of the I/O cabinet is connected to the same ground as that of the UPS to ensure equal potential.

2. Each hardware device operator station, engineer station, network switch, server host, and system display are grounded using the shell or directly connect the power ground cable to the electrical grounding network.

3. Connect the 40 end of the analog module of the I/O component, that is, the negative end of the 24 volt DC module, to the logical bus bar, which is connected to the shielded ground, and then to the total ground bus bar.

4. Shielded ground The protection ground of the field control station should be connected to the ground trunk from the ground screw under the cabinet, and the shielded ground of the field control station should be connected to the common connection board from the ground bus bar.

5. Grounding resistance test The resistance of the grounding system is tested to ensure that the grounding can meet the requirements of the control system manufacturer.

The shell, instrument panel, cabinet, box, box, cable trough, protective tube, bracket, base and other normal metal parts of the electric instrument, which may have dangerous voltage due to insulation damage, should be grounded for protection. For local meters and switches whose power supply voltage is not higher than 36V, do not do protective grounding when there is no special requirement in the design document.