The switchgear refers to a complete set of power distribution equipment assembled from primary equipment and secondary equipment according to a certain line scheme, which is used to control and protect the lines and equipment. The structure of the switch cabinet is generally similar, mainly divided into bus room, circuit breaker room, secondary control room (instrument room), feeder room, each room is generally separated by steel plate.

Internal components include: bus (busbar), circuit breaker, regular relay, comprehensive relay protection device, metering instrument, isolation knife, indicator lamp, grounding knife, etc.

1. According to the installation method of circuit breaker

(1) Removable type or handcart type: it means that the main electrical components (such as circuit breakers) in the cabinet are installed on the withdrawable handcart. Because the handcart cabinet has good interchangeability, it can greatly improve the reliability of power supply. Commonly used handcart types include: isolated handcart, metering handcart, circuit breaker handcart, PT handcart, capacitor handcart and used handcart.

(2) Fixed type: all electrical components (such as circuit breakers or load switches, etc.) in the cabinet are fixed installation, and the fixed switch cabinet is relatively simple and economical.

▲ Fixed switch cabinet

2. By installation location

(1) Used for indoor (indicated by N); Indicates that it can only be installed and used indoors.

(2) Used outdoors (represented by W); It means that it can be installed and used outdoors.

3. According to the cabinet structure

(1) metal enclosed armored switchgear, the main components (such as: circuit breaker, transformer, bus, etc.) are respectively installed in the grounded metal enclosed switchgear in the compartment separated by metal partition.

(2) Metal enclosed compartment switchgear, similar to armored metal enclosed switchgear, its main electrical components are also installed in a separate compartment, but with one or more non-metallic partitions that meet a certain level of protection.

(3) metal closed box switch cabinet switch cabinet shell for metal closed switch equipment.

(4) Open switch cabinet, no protection level requirements, the shell is part of the open switch equipment.

　　Two models GGD, GCK, GCS, MNS, MCS introduction

1.GGD Series

(1) Purpose

GGD AC low-voltage power distribution cabinet is suitable for power distribution systems with AC 50Hz, rated working voltage 380V and rated working current 1000-3150A of power users such as substations, power plants, factories and mines, etc., as power conversion, distribution and control of power, lighting and power generation and distribution equipment.

GGD AC low-voltage distribution cabinet is based on the Ministry of Energy, the majority of power users and the requirements of the design department, in accordance with the principles of safety, economy, reasonable and reliable design of the new low-voltage distribution cabinet.

The product has the characteristics of high breaking capacity, good dynamic thermal stability, flexible electrical scheme, convenient combination, series, strong practicability, novel structure and high protection level. Can be used as a low-voltage switchgear replacement products.

(2) Product model and meaning

▲ G-low voltage power distribution cabinet; G-fixed installation and fixed wiring; D-power cabinet

(3) Structural characteristics

The cabinet body of GGD AC low-voltage power distribution cabinet adopts the general cabinet form. The frame is partially welded and assembled with 8MF cold-formed steel, and has 20-mold mounting holes, with high general coefficient.

GGD cabinet fully consider the heat dissipation problem. There are different numbers of heat dissipation slot holes at the upper and lower ends of the cabinet body. When the electrical components in the cabinet generate heat, the heat rises and is discharged through the upper slot hole, while cold air is continuously added into the cabinet through the lower slot hole, so that the sealed cabinet body forms a natural ventilation channel from bottom to top to achieve the purpose of heat dissipation.

According to the requirements of modern industrial product modeling design, GGD cabinet adopts the method of golden section ratio to design the shape of the cabinet body and the division size of each part, so that the whole cabinet is beautiful and elegant and has a new look.

The top cover of the cabinet body can be removed when necessary to facilitate the assembly and adjustment of the main bus on site. The four corners of the cabinet top are equipped with lifting rings for lifting and shipping.

The protection level of the cabinet is IP30, and users can also choose between IP20-IP40 according to the requirements of the environment.

2.GCK Series

▲ G is closed switch cabinet C is withdrawable K is control center

　　(1) Product model and meaning

The PC cabinet is responsible for the power supply of large-capacity loads, so the frame type air switch is generally used in the PC. A PC has only 2-3 loops. According to the power design regulations, the loads of 75KW and above are powered by the PC.

MCC is responsible for supplying power to small and medium-sized capacity loads, so plastic shell switches are generally used in MCC. An MCC can have 5-20 circuits. According to the power design regulations, loads below 75KW are powered by MCC.

GCK low-voltage withdrawable switchgear (hereinafter referred to as switchgear) is composed of power distribution center (PC) cabinet and motor control center (MCC). The device is suitable for AC 50(60)HZ, rated working voltage is less than or equal to 660V, rated current 4000A and below the control and distribution system, as power distribution, motor control and lighting and other power distribution equipment.

GCK switchgear conforms to the IEC60439-1 "low-voltage switchgear and control equipment", GB7251.1-1997 "low-voltage switchgear and control equipment", GB/T14048.1-93 "general rules of low-voltage switchgear and control equipment" and other standards.

And with high breaking capacity, good dynamic thermal stability, advanced and reasonable structure, flexible electrical scheme, series, strong versatility, any combination of various scheme units, a cabinet. It has the advantages of more circuits, saving floor space, high protection level, safety and reliability, and convenient maintenance.

(2) Structural characteristics

The whole cabinet adopts assembled combination structure, module hole installation, parts versatility, good applicability, high degree of standardization.

The upper part of the cabinet is a bus room, the front part is an electrical room, and the rear part is a cable inlet and outlet room. Steel plates or insulating plates are provided for isolation between each room to ensure safety.

The door of the drawer compartment of MCC cabinet is mechanically interlocked with the operating handle of the circuit breaker or isolating switch, and the door can be opened only when the handle is in the breaking position.

The receiving switch, connecting switch and drawer of MCC cabinet have three positions: on position, test position and off position.

The top of the switch cabinet can be equipped with a bus bridge according to the power demand.

　3.GCS Series

▲ G-closed switchgear; C- withdrawal type; S-Senyuan Electrical System

　　(1) Product model and meaning

(2) Use

GCS type low-voltage withdrawable switchgear is used for power, power distribution, motor centralized control and capacitance compensation in power generation and power supply systems with three-phase AC frequency of 50Hz, rated working voltage of 400V(690V) and rated current of 4000A and below. It is widely used in power plants, petroleum, chemical industry, metallurgy, textile, high-rise buildings and other places. It can also be used in large power plants, petrochemical systems and other places with high degree of automation and computer interface.

Executive standard: This product meets the requirements of GB7251.1-1997 "low-voltage switchgear and control equipment" and JB/T9661-1999 "low-voltage withdrawable switchgear.

(3) Structural features:

The frame adopts 8MF type open section steel, and the main frame is equipped with Φ9.2mm mounting holes with modulus E = 20mm and 100mm, which makes the frame assembly flexible and convenient.

The functional rooms of the switch cabinet are isolated from each other, and the compartments are divided into functional unit room, bus room and cable room. The role of each chamber is relatively independent.

The horizontal bus is arranged in the rear of the cabinet to enhance the ability of the bus to resist electrodynamic force, which is the basic measure to make the main circuit have high short-circuit strength.

The design of the cable compartment makes it very convenient for the cable to enter and exit up and down.

The modulus of the drawer height is 160mm. The drawer changes only in the height dimension, and its width and depth dimensions remain unchanged. Drawers of the same functional unit have good interchangeability. Unit loop rated current 400A and below.

The drawer panel shall be marked with the position of separation, closing, test and extraction. The drawer unit is provided with a mechanical interlock. 1 The drawer unit is the main body, and it has both draw-out and fixation, and can be mixed and combined for arbitrary use.

The protection level of the cabinet is IP30 IP40, and it can also be selected according to user needs.

　　4.MNS Series

Products manufactured in accordance with the technology transferred from ABB Switzerland

(1) Purpose

MNS type low-voltage withdrawable complete set of switchgear (hereinafter referred to as switchgear) In order to meet the needs of the development of the power industry, refer to the foreign MNS series low-voltage switchgear design and improve the development of advanced low-voltage switchgear. The product conforms to the national standards GB7251, VDE660 and the ZBK36001-89 "low-voltage withdrawable complete set of switchgear" and international standards IEC439, can be widely used in power plants, substations, industrial and mining enterprises, buildings, hotels, municipal construction and other low-voltage distribution system.

(2) Structural characteristics

MNS type low voltage switch cabinet frame is a combined structure, the basic skeleton is assembled by C steel. All structural parts of the cabinet frame are galvanized, and are firmly connected to the basic cabinet frame by self-tapping locking screws or 8.8-grade hexagonal bolts, and the doors, partitions, mounting brackets, bus function units and other components corresponding to the change of the scheme are assembled into a complete switch cabinet. The internal dimensions, component dimensions and compartment dimensions of the switchgear shall be changed according to modularity (E = 25mm).

Each cabinet of MNS type combined low voltage switch cabinet is divided into three rooms, namely, horizontal bus room (at the rear of the cabinet), drawer room (at the front of the cabinet) and cable room (at the lower part of the cabinet or at the right side of the front of the cabinet). The chambers are separated from each other by steel plates or high-strength flame-retardant plastic function plates, and the upper and lower drawers are separated by metal plates with ventilation holes, so as to effectively prevent the switching elements from arcing caused by faults or accidents caused by short circuits between busbars and other lines.

The structural design of MNS type low-voltage switchgear can meet the requirements of various incoming and outgoing line schemes: up-in and up-out, up-in and down-out, down-in and up-out, down-in and down-out.

Compact design: a smaller space to accommodate more functional units.

The structural parts have strong versatility and flexible assembly, with E = 25mm as the modulus, the structure and the extraction unit can be combined arbitrarily to meet the needs of system design.

The busbar is protected by high-strength flame-retardant and high-insulation-strength plastic function board, which has anti-fault arc performance and makes the operation and maintenance safe and reliable.

The mechanical interlocking mechanism of drawers of various sizes conforms to the standard, and has three obvious positions of connection, test and separation, which is safe and reliable.

Standard module design: respectively can be composed of protection, operation, conversion, control, regulation, measurement, indication and other standard units, can be assembled according to the requirements of any.

The cabinet body can be selected according to the different requirements of the working environment.

5.MCS Series

　　MNS improved

(1) Use:

MCS intelligent low-voltage withdrawable switchgear is a kind of advanced product developed by integrating the advantages of other low-voltage products. It is suitable for three-phase AC 50HZ,60HZ, rated voltage 380V, rated current 4000A and below power distribution system of three-phase four-(V) wire power system in power plants, petrochemical industry, metallurgy, telecommunications, light industry, textile, high-rise buildings and other civil and industrial and mining enterprises, in large power plants, petrochemical, telecommunications systems and other high degree of automation, requiring computer interface places, as a power, power supply system in the distribution, motor centralized control, reactive power compensation of low-voltage power distribution devices.

(2) Structural features:

The basic frame of the switch cabinet is assembled with C- type (or 8MF type) open section steel, with uniform appearance, high precision and good drawer interchangeability.

The width of the MCC cabinet is only 600mm, and the use space is large, which can accommodate more functional units and save construction land.

The components in the cabinet can be configured with various types of switches according to the different needs of users to better ensure the high reliability of the product.

The device can reserve an automation interface, and the intelligent module can also be installed on the switch cabinet to realize three remote functions such as remote signaling, telemetry and remote control.

Drawer functional units can be divided into MCCI, MCCII, MCCIII three.

MCCI type: drawer width 600mm, height 180mm,360mm,540mm three kinds, each cabinet can be installed height of 1800mm, according to the required drawer size combination, can hold up to 10 units, suitable for large current motor control center and feed loop. MCCII type: drawer width 600/2mm, height 200mm, mountable height 1800mm, combined according to the required drawer size, can hold up to 18 units, suitable for units below 100A.

MCCIII type: drawer width 600/2mm, height 180mm,360mm,540mm three kinds, can be installed height 1800mm, according to the required drawer size combination, can hold up to 20 circuits, suitable for units below 100A.

Operating mechanism: each drawer is equipped with a specially designed operating mechanism, which is used to break and close the switch, and has various anti-misoperation functions such as mechanical interlocking. MCCI drawer has a set of positioning devices in four positions of "disconnect", "test", "work" and "move out". The drawer is of a rolling structure. MCCII and MCCIII drawer units are of push-pull type and are provided with positioning devices, and anti-misoperation function.

　Three the difference between various types of switch cabinet

1. GCS, GCK, MNS, GGD switch cabinet difference

GGD is a fixed cabinet, GCK, GCS, MNS is a chest of drawers. GCK cabinet is different from GCS and MNS cabinet drawer propulsion mechanism. GCS cabinet can only be used as single-sided operation cabinet with a cabinet depth of 800mm,MNS cabinet can be used as double-sided operation cabinet with a cabinet depth of 1000mm.

GCK is a very old cabinet type in China. The profile used at that time had poor strength and the operating mechanism was not very flexible. Most of the production now absorbs the advantages of GCS cabinet.

GCK is obviously different from GCS and MNS. The horizontal bus is traditionally located on the top of the cabinet. The vertical bus has no flame retardant plastic function board. The cable outlet can be backward or can be made into the right cable room outlet. However, the drawer pushing mechanism is different from GCS and MNS and is relatively simple.

GCS is a new generation of drawer switch cabinet designed by Senyuan Company in the mid -1990 s with reference to MNS cabinet type of ABB Company. Its main structure is similar to MNS, and its main bus is rear-mounted. Different from MNS, the drawer module uses the 20mm module commonly used in China (MNS is 25mm); The drawer adopts a propulsion mechanism, which is more convenient and flexible to operate.

MNS cabinet can be operated on both sides, the cabinet depth is 1000mm, and a single cabinet can hold up to 36 circuits (with 1/4 drawer), while GCS can only be operated on one side, the cabinet depth is 800mm, and the maximum is 22.

The material used in MNS cabinet is aluminum-zinc plate, fully assembled structure, no post-treatment (galvanized).

The horizontal bus bars of MNS and GCS are separated from the front left drawer unit and the front right electronic outlet room by partitions. Their vertical bus bars are assembled in flame retardant plastic function boards to be more reliable.

Requirements for 3C mandatory certification test sample cabinet: GCK minimum drawer unit 1 modulus, GCS minimum drawer unit 1/2 modulus, MNS (imported ABB technology) minimum drawer unit 1/4 modulus.

Modulus: GCK (Senyuan) minimum drawer unit 1 modulus: GCS minimum drawer unit 1/2 modulus, MNS (imported ABB technology) minimum drawer unit 1/4 modulus.

Busbar: The horizontal busbars of MNS and GCS are separated from the front left drawer unit and the front right cable outlet room by partitions. Their vertical busbars are assembled in flame retardant plastic function boards for more reliability. The GCK horizontal bus is located on the top of the cabinet. The vertical bus does not have a flame retardant plastic function board. The cable outlet can be pulled out later or can be made into the right cable room outlet. However, the drawer advancing mechanism is different from GCS and MNS and is relatively simple.

Drawer: GCS can only have 1/2 drawer at minimum, MNS has 1/4 drawer, MNS drawer has another interlocking mechanism, while GCS only has the switch itself.

Difference between GCS and MNS

(1) Different origin: GCS is independently designed and developed in China. MNS was introduced from ABB. GCS has been put on the market since 1996, and many aspects are modeled after MNS, such as horizontal bus bars, incoming and outgoing lines, etc.

(2) different steel type assembly: GCS is assembled by 8MF(KS) steel, and MNS is assembled by C(KB) steel. GCS is superior to MNS in terms of strength. But aesthetically speaking, MNS is better than GCS, and many manufacturers use C profiles to make GCS. The maximum current of GCS original design can only reach 4000A, while MNS can reach higher. After many improvements, GCS now reaches 6300A.

(3) The drawer mechanism is different: GCS uses a rotary propulsion mechanism (CJG-1 ~ 3), while MNS uses a large interlocking. In contrast, GCS drawers are a little more labor-saving than MNS drawers.

(4) Different installation modules: MNS cabinet installation module is 25mm while GCS is 20mm,GCS can be made into 11 drawers at most, MNS can be made into 9 drawers, but MNS can be made into double-sided cabinets (both front and back drawers are installed). Therefore, GCS can make up to 22 drawers, while MNS can make 72 drawers (GCS does not 1/4 unit drawers but MNS does). MNS has advantages in small current. GCS has some advantages in high current.

　　Four various types of switch cabinet advantages and disadvantages

Generally speaking, the draw-out cabinet saves more places, is convenient to maintain, and has many outlet circuits, but the cost is expensive; while the fixed type has fewer outlet circuits and occupies more land. If the customer provides too few places, the fixed one should be changed to the withdrawable one.

1. GGD AC low-voltage switchgear

The switch cabinet has the advantages of reasonable mechanism, convenient installation and maintenance, good protection performance, high breaking capacity, large capacity, strong segmentation ability, strong dynamic stability, and wide applicability of electrical solutions. It can be used as a replacement product.

Disadvantages: fewer circuits, units can not be arbitrarily combined and occupy a large area, can not communicate with the computer.

2. GCK switch cabinet

It has high breaking capacity, good dynamic thermal stability, advanced and reasonable structure, flexible electrical scheme, series, strong versatility, and any combination of various scheme units. A cabinet body has the advantages of more circuits, saving floor space, high protection level, safety and reliability, and convenient maintenance.

Disadvantages: The horizontal bus is located on the top of the cabinet. The vertical bus has no flame retardant plastic function board and cannot communicate with the computer.

3. GCS low-voltage withdrawable switchgear

It has high technical performance indicators, can adapt to the development needs of the power market, and can compete with existing imported products. According to the principle of safety, economy, reasonable and reliable design of the new low-voltage withdrawable switch cabinet, but also has a breaking, high connection capacity, good dynamic thermal stability, flexible electrical solutions, easy combination, series of strong practicality, novel structure, high protection level.

4. MNS series switch cabinet

Compact design, with a smaller space can accommodate more functional units. The structure has strong versatility and flexible assembly. The C- shaped profile with 25mm modulus can meet the requirements of various structural forms, protection levels and use environments.

Using standard module design, respectively, can be composed of protection, operation, conversion, control, regulation, instruction and other standard units, the user can according to the need to choose any assembly.

High technical performance, the main parameters to reach the contemporary international technical level. Compression site, three degree of high, can greatly compress the storage and transportation of pre-production site. The assembly is convenient and does not require special complexity.

5.MCS type low voltage withdrawable switch cabinet

The cabinet body is assembled with C- shaped steel, with uniform appearance, high precision and good drawer interchangeability.

The width of the MCC cabinet is only 600mm, and the use capacity is large, which can accommodate more functional units and save construction land.

The components in the cabinet can be configured with various types of switches according to the different needs of users to better ensure the high reliable operation of the product.

This device can reserve the automation interface, and also can install the module on the switch cabinet to realize the "three remote" functions and control equipment such as remote signaling, telemetry and remote control.

Disadvantages: high cost, for small and medium-sized users have a certain degree of difficulty.