MNS low-voltage withdrawable switchgear

Extraction type series combined low-voltage switchgear (hereinafter referred to as switchgear). It is suitable for AC 50~60HZ, rated working voltage AC 380V, rated insulation voltage 660V, 1600KVA and below The power system of the distribution transformer is used as the power distribution, power, lighting, reactive power compensation, motor control center, and the standard cabinet is designed with a fixed solution and a mixed system of extraction scheme to meet the different needs of the majority of users.

2 Conditions of use

2 . 1. The ambient air temperature is not higher than +40°C, and the average temperature within 24 hours is not higher than +35°C and not lower than -5°C;

2 . 2. The air is clean, and the relative humidity does not exceed 50% at the maximum temperature of +40°C, and higher relative humidity is allowed at the lower temperature, such as 90% at +20°C;

2 . 3. Places without fire, explosion hazards, serious dust, chemical corrosion and violent vibration;

2 . 4. The altitude does not exceed 2000m;

2 . 5 The switchgear is suitable for transportation and storage at the following temperatures, -25°C~ +55°C, and not more than +70°C in a short period of time (no more than 24 h);

2 . 6 If the above conditions of use cannot be met, the user and the manufacturer shall negotiate and solve the problem.

3 Structural characteristics

The basic frame of the switchgear is a combined assembly structure, all of which are fastened and connected by screws, plus doors, partitions, supports and busbars, drawers and electrical components to form a complete switchgear with the following characteristics:

3 . 1. The external dimensions of the frame and parts and the size of the hole are changed according to the modulus E =20mm;

3 . 2 Because all the structural parts of the frame are fastened and connected by screws, which avoids welding deformation and stress, improves precision, has strong versatility, good applicability, and has large mechanical strength, it fully meets the various performance requirements and changes of the switchgear;

3 . 3 In the MCC scheme, the switchgear is divided into three areas (rooms), the busbar area, the electrical equipment area and the cable area, and the three areas are separated by steel plates to ensure the normal operation of the line and effectively prevent the expansion of faults.

3 . 4 In the PC solution, the manual mechanism of AH and ME circuit breaker protrudes out of the door, and there is no need to open the door panel when operating by hand, which is safe and convenient;

3 . 5 In the fixed scheme, that is, the characteristics of the fixed scheme such as simplicity, practicality, and low cost are retained, and it has the same appearance shape as the chest of drawers, and its interior is also divided into bus line area, electrical equipment area and cable area, and the three areas are also separated by steel plates or insulating plates, which are safe and reliable, and are ideal equipment to replace the old fixed products in China.

3 . 6 MCC cabinet drawers have four standard sizes, they are 200, 300, 400, 600, light structure, easy assembly, high dimensional accuracy, can be changed with the design and user requirements, the drawer unit has good interchangeability, and has a working position and separation position, the handle can be locked by a padlock, in the specified disconnection position;

3 . 7 The switchgear is designed for two types of power supply and consumption of three-phase four-wire and three-phase five-wire distribution system, the neutral bus N wire and the protective grounding bus PE wire are installed on the lower side of the cabinet, and the outlet end is connected with a busbar, so that the user can connect the cable very conveniently.

3 . 8 In order to ensure the reliable continuity of grounding, all general components such as drawer rails in the cabinet are galvanized;

3 . 9 Without reducing the protection level of the shell, the top of the switch cabinet is equipped with a natural ventilation mesh cover.

In short, the switchgear adopts an imitation of foreign advanced cabinet and rack structure, with high mechanical strength and high degree of standardization, and the overall compliance with IEC439 international standards and GB7251 national standards, and its protection level meets the IP3X in GB4208, which is equivalent to IP30 in IEC529.

4 Special attention should be paid to the following situations in the design and selection of products

4 . 1 The total height of the product is 2200mm, the top is the busbar, the middle part is the installation height of the electrical components, the highest is 1800mm, and the bottom part of the fixing scheme should be subtracted by 200mm, the maximum is 1600mm (except for the scheme given 1800mm).

4 . 2 There are four types of cabinet widths: 400, 600, 800, 1000, in the fixed scheme should pay attention to whether the cabinet width is the same when different schemes are selected in a cabinet, different cabinet width schemes can not be combined in a cabinet, unless the narrower scheme is allowed to be combined in a wider cabinet, in the drawer scheme except for the AH, ME, DWX15 switch scheme, the others are 600mm, the width cannot be combined with different width schemes.

4 . The depth of the 3 cabinets is 800mm, but when the upper and outgoing lines are all 1000mm, except for the incoming cabinets.

4 . 4 There are different capacity limits in each standard scheme. After the combination of each cabinet scheme, it is necessary to mark the project number, the model and specification of the electrical components, the operation type of the switch and the combination diagram of the switchgear, in the standard single-circuit scheme, the switch is equipped with mechanical interlocking, so that the switch can only open the door panel when it is disconnected, and special attention should be paid to the selection of the switch model in the design and selection to ensure the performance requirements of the overall power distribution device.

5 Technical Parameters (see Table 1)

Technical parameters of switchgear (Table 1)

6. Dimensions

Fig.1 Overall dimensions of busbar cabinet and inlet cabinet I

Fig. 2 The outline dimensions of the inlet cabinet type II

Fig.3 Overall dimensions of control cabinet and capacitor cabinet

7. Mounting size

Fig.4 Installation size A: inlet cabinet B: feeder cabinet

Fig.5 Installation size of string cabinet A: inlet cabinet B: feeder cabinet