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.

適用于額定工作電壓不超過4000V低壓配電系統中的動力、配電、照明配電之用。低壓配電屏是電廠里應用廣的低壓成套裝置，下面介紹一下ABB生產的MNS系列低壓配電屏的結構原理。樹上鳥教育電氣設計師在線教學課程

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、配電柜框架

1、 Distribution cabinet frame

開關柜由獨立的單柜通過螺栓連接成一體，框體如圖3所示。柜體的底部由前后面以3毫米覆鋁鋅的鋼片牢固焊接板組合制成，每一個配電柜均通過把水平與垂直的C型骨架用螺拴精確拼接而成，利用拴接和壓板設計形成一個牢固的結構。

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型骨架根據德國工業標準43660間隔25毫米沖孔，以2毫米厚高強度、不銹覆鋁鋅鋼板制成。所有的框架部件以螺紋成型自攻螺絲鎖緊，配電柜框架為模塊式設計，僅改變隔室分隔板的位置即可隨意擺列功能單元，頂部骨架帶有吊耳。

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、母線

2、 Busbar

銅質母線根據德國工業標準制造而成，開關柜后部的獨立母線室內可安裝3相或4相水平母線， MNS可以使用安裝在這一母線隔室上下兩層的兩個母線系統，配電盤母線如圖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母線系統具有一個獨特的設計，使用涂有ESLOK（一種樂泰型化合物）的螺栓、圓錐形彈簧墊圈以及螺紋板，利用扭矩扳手拉緊，此設計已通過免維護認證，并同樣適用于在現場完成的互連，所有母線的連接均從開關柜的正面操作。

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.

母線分為主母線和配電母線，主母線布置在開關柜的背部（母線小室內），可分為上下兩層。雙層主母線系統分別布置在上、下兩層；單層主母線系統布置在上層或下層；主母線單聯、串聯、并聯均可；母線材質為銅（Cu），截面積為30*10mm， 40*10mm， 60*10mm三種規格。配電母線用于功能單元組件與母線之間的連接，配電母線（垂直母線）分布在母線小室內，母線材質為銅（Cu），單根直角型銅牌，其截面為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

配電母線（直角型銅排）安裝在絕緣多功能分隔板中，同整個母線一起，無需另外增加隔板即可達到抗電擊防護等級（IP20）的要求，多功能分隔板如圖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.

圖5 配電盤分隔板

Figure 5 Distribution Panel Partition Board

多功能分隔板有抗故障電弧性能，也作為裝置小室和母線小室的隔離。可有效隔離故障電弧，防止手指誤插入(IP20)，具有絕緣、隔離、自熄、阻燃、熄弧、滅弧的作用。

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、轉接件

4、 Adapter

轉接件單元方便了垂直配電母線的水平配電，使4或2個出線功能單元可以緊密在排列在電柜的同一個水平位置內，從而優化了開關柜內可利用的空間。四回路轉接件的額定電流為每個回路45A，兩回路為每回路63A。轉接件單元已預留了出線電纜，可在電纜室中接外部出線。轉接件單元有3極和4極兩種規格，每一個功能單元有20個輔助端子。

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

一次接插件是一個精確設計的部件，每一個觸點在制造過程中均經過功能和壓力測試，然后將制造日期和觸點壓力與序列號一道，刻在觸點組件上。一次插件為鍍錫，額定電流為250A。根據現場電纜尺寸的不同，其線鼻子將有差異。每個一次插件都有插件保護蓋，確保在與配電母線接觸之前觸點完全隔離。

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、電纜接線

6、 Cable wiring

進、出線電纜和控制線接線位置位于電纜小室的右側電纜安裝導軌上，主回路端子位于其后部，控制線端子位于其前方45°方向上。控制線端子的接線可用螺絲或插入式線鼻子連接，或者用端子連接。主回路端子小于63A的抽出式組件，轉接件上配有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、抽屜

7、 Drawer

MNS開關柜的模塊化設計是基于25毫米的模數孔的（根據德國工業標準436600）；該模數以字母E表示，即E=25mm。8E抽屜的高度為8x25mm=200mm。組件規格為：8E/4、8E/2、8E、16E、24E等等，如圖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、各種型號開關柜的區別

8、 Differences in various types of switchgear

lGCS、GCK、MNS、GGD開關柜區別

Differences in lGCS, GCK, MNS, GGD switchgear

GGD是固定柜，GCK、GCS、MNS是抽屜柜。

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

GCK柜和GCS、MNS柜抽屜推進機構不同；

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

GCS柜只能做單面操作柜，柜深800mm，

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

MNS柜可以做雙面操作柜，柜深1000mm。

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