Low voltage distribution panel, also known as low-voltage switch panel or distribution cabinet, is a kind of combined electrical equipment that is installed in a metal cabinet according to a certain wiring scheme to control, protect, measure, distribute and monitor the switchgear, measuring instruments, protection devices and auxiliary equipment required by low-voltage circuits.

适用于额定工作电压不超过4000V低压配电系统中的动力、配电、照明配电之用。低压配电屏是电厂里应用广的低压成套装置，下面介绍一下ABB生产的MNS系列低压配电屏的结构原理。树上鸟教育电气设计师在线教学课程

Suitable for power, distribution, and lighting distribution in low-voltage distribution systems with a rated working voltage not exceeding 4000V. The low-voltage distribution panel is the most widely used low-voltage complete device in power plants. Below is an introduction to the structural principle of ABB's MNS series low-voltage distribution panel. Tree Bird Education Electrical Designer Online Teaching Course

一、配电柜框架

1、 Distribution cabinet frame

开关柜由独立的单柜通过螺栓连接成一体，框体如图3所示。柜体的底部由前后面以3毫米覆铝锌的钢片牢固焊接板组合制成，每一个配电柜均通过把水平与垂直的C型骨架用螺拴精确拼接而成，利用拴接和压板设计形成一个牢固的结构。

The switchgear is composed of independent single cabinets connected together by bolts, and the frame is shown in Figure 3. The bottom of the cabinet body is composed of 3mm aluminum zinc coated steel sheet firmly welded plates at the front and back. Each power distribution cabinet is precisely spliced with bolts by Vertical and horizontal C-shaped skeleton, and a firm structure is formed by using bolt connection and pressing plate design.

C型骨架根据德国工业标准43660间隔25毫米冲孔，以2毫米厚高强度、不锈覆铝锌钢板制成。所有的框架部件以螺纹成型自攻螺丝锁紧，配电柜框架为模块式设计，仅改变隔室分隔板的位置即可随意摆列功能单元，顶部骨架带有吊耳。

The C-shaped skeleton is punched at 25mm intervals according to German industrial standard 43660 and made of 2mm thick high-strength, stainless aluminum zinc coated steel plate. All frame parts are locked with thread forming Self-tapping screw. The distribution cabinet frame is of modular design. Functional units can be arranged at will only by changing the position of the compartment partition board. The top frame is equipped with lifting lugs.

二、母线

2、 Busbar

铜质母线根据德国工业标准制造而成，开关柜后部的独立母线室内可安装3相或4相水平母线， MNS可以使用安装在这一母线隔室上下两层的两个母线系统，配电盘母线如图4所示。

The copper busbar is manufactured according to German industrial standards. The independent busbar compartment at the rear of the switchgear can install 3-phase or 4-phase horizontal busbar. MNS can use two busbar systems installed on the upper and lower floors of this busbar compartment. The distribution panel busbar is shown in Figure 4.

MNS母线系统具有一个独特的设计，使用涂有ESLOK（一种乐泰型化合物）的螺栓、圆锥形弹簧垫圈以及螺纹板，利用扭矩扳手拉紧，此设计已通过免维护认证，并同样适用于在现场完成的互连，所有母线的连接均从开关柜的正面操作。

The MNS bus system has a unique design that uses bolts coated with ESLOK (a Loctite type compound), conical spring washers, and threaded plates, and is tightened using a torque wrench. This design has been certified maintenance free and is also suitable for on-site interconnections. All bus connections are operated from the front of the switchgear.

母线分为主母线和配电母线，主母线布置在开关柜的背部（母线小室内），可分为上下两层。双层主母线系统分别布置在上、下两层；单层主母线系统布置在上层或下层；主母线单联、串联、并联均可；母线材质为铜（Cu），截面积为30*10mm， 40*10mm， 60*10mm三种规格。配电母线用于功能单元组件与母线之间的连接，配电母线（垂直母线）分布在母线小室内，母线材质为铜（Cu），单根直角型铜牌，其截面为L型50*30*5mm。

The busbar is divided into main busbar and distribution busbar. The main busbar is arranged at the back of the switchgear (busbar compartment) and can be divided into upper and lower layers. The double-layer main busbar system is arranged on the upper and lower layers respectively; The single-layer main busbar system is arranged in the upper or lower layers; The main busbar can be connected in single, series, or parallel; The busbar material is copper (Cu), with a cross-sectional area of 30 * 10mm, 40 * 10mm, and 60 * 10mm. The distribution busbar is used for the connection between functional unit components and the busbar. The distribution busbar (vertical busbar) is distributed in the busbar compartment, and the busbar material is copper (Cu). A single right angle copper plate has an L-shaped section of 50 * 30 * 5mm.

三、多功能分隔板

3、 Multifunctional partition board

配电母线（直角型铜排）安装在绝缘多功能分隔板中，同整个母线一起，无需另外增加隔板即可达到抗电击防护等级（IP20）的要求，多功能分隔板如图5所示。

The distribution busbar (rectangular copper bar) is installed in an insulated multifunctional partition board, which, together with the entire busbar, can meet the requirements of electric shock protection level (IP20) without the need for additional partitions. The multifunctional partition board is shown in Figure 5.

图5 配电盘分隔板

Figure 5 Distribution Panel Partition Board

多功能分隔板有抗故障电弧性能，也作为装置小室和母线小室的隔离。可有效隔离故障电弧，防止手指误插入(IP20)，具有绝缘、隔离、自熄、阻燃、熄弧、灭弧的作用。

The multifunctional partition board has anti fault arc performance and also serves as an isolation between the device compartment and the busbar compartment. It can effectively isolate faulty arcs and prevent finger insertion (IP20), and has the functions of insulation, isolation, self extinguishing, flame retardant, arc extinguishing, and arc extinguishing.

四、转接件

4、 Adapter

转接件单元方便了垂直配电母线的水平配电，使4或2个出线功能单元可以紧密在排列在电柜的同一个水平位置内，从而优化了开关柜内可利用的空间。四回路转接件的额定电流为每个回路45A，两回路为每回路63A。转接件单元已预留了出线电缆，可在电缆室中接外部出线。转接件单元有3极和4极两种规格，每一个功能单元有20个辅助端子。

The adapter unit facilitates the horizontal distribution of vertical distribution buses, allowing 4 or 2 outgoing functional units to be closely arranged in the same horizontal position of the switchgear, thereby optimizing the available space within the switchgear. The rated current of the four circuit adapter is 45A per circuit, and 63A per circuit for the two circuits. The adapter unit has reserved outgoing cables that can be connected to external outlets in the cable compartment. The adapter unit has two specifications: 3-pole and 4-pole, and each functional unit has 20 auxiliary terminals.

五、一次插接件

5、 Primary connector

一次接插件是一个精确设计的部件，每一个触点在制造过程中均经过功能和压力测试，然后将制造日期和触点压力与序列号一道，刻在触点组件上。一次插件为镀锡，额定电流为250A。根据现场电缆尺寸的不同，其线鼻子将有差异。每个一次插件都有插件保护盖，确保在与配电母线接触之前触点完全隔离。

A one-time connector is a precisely designed component, where each contact undergoes functional and pressure testing during the manufacturing process. The manufacturing date and contact pressure are then engraved on the contact assembly along with the serial number. The primary plug-in is tin plated with a rated current of 250A. The cable nose will vary depending on the size of the on-site cable. Each plug-in has a protective cover to ensure complete contact isolation before contact with the distribution bus.

六、电缆接线

6、 Cable wiring

进、出线电缆和控制线接线位置位于电缆小室的右侧电缆安装导轨上，主回路端子位于其后部，控制线端子位于其前方45°方向上。控制线端子的接线可用螺丝或插入式线鼻子连接，或者用端子连接。主回路端子小于63A的抽出式组件，转接件上配有PE端子。

The wiring positions of the incoming and outgoing cables and control lines are located on the right cable installation guide rail of the cable compartment, with the main circuit terminal located at the rear and the control line terminal located at a 45 ° direction in front of it. The wiring of control wire terminals can be connected with screws or plug-in wire noses, or with terminals. For withdrawable components with main circuit terminals less than 63A, the adapter is equipped with PE terminals.

七、抽屉

7、 Drawer

MNS开关柜的模块化设计是基于25毫米的模数孔的（根据德国工业标准436600）；该模数以字母E表示，即E=25mm。8E抽屉的高度为8x25mm=200mm。组件规格为：8E/4、8E/2、8E、16E、24E等等，如图7所示。

The modular design of MNS switchgear is based on 25mm modular holes (according to German industrial standard 436600); The modulus is represented by the letter E, which means E=25mm. The height of the 8E drawer is 8x25mm=200mm. The component specifications are 8E/4, 8E/2, 8E, 16E, 24E, etc., as shown in Figure 7.

八、各种型号开关柜的区别

8、 Differences in various types of switchgear

lGCS、GCK、MNS、GGD开关柜区别

Differences in lGCS, GCK, MNS, GGD switchgear

GGD是固定柜，GCK、GCS、MNS是抽屉柜。

GGD is a fixed cabinet, while GCK, GCS, and MNS are drawer cabinets.

GCK柜和GCS、MNS柜抽屉推进机构不同；

The drawer pushing mechanism of GCK cabinet is different from that of GCS and MNS cabinets;

GCS柜只能做单面操作柜，柜深800mm，

The GCS cabinet can only be used as a single side operation cabinet, with a depth of 800mm,

MNS柜可以做双面操作柜，柜深1000mm。

MNS cabinet can be used as a double-sided operation cabinet with a depth of 1000mm.