MNS distribution cabinet, MNS type low-voltage withdrawable complete set of switchgear (hereinafter referred to as switchgear) is an advanced low-voltage switchgear developed with reference to the design of foreign MNS series low-voltage switchgear and improvements to meet the needs of the development of the electric power industry. This product complies with the national Standards GB7251, VDE660 and ZBK36001-89 "Low-voltage withdrawable switchgear complete set" and international standard IEC439 stipulate that MNS type low-voltage switchgear is suitable for various power supply and distribution needs, and can be widely used in power plants, substations, industrial and mining enterprises, building hotels , municipal construction and other low-voltage distribution systems.
Conditions for use of MNS chest of drawers
The ambient air temperature shall not be higher than +40℃ and not lower than -5℃, and its average temperature within 24 hours shall not be higher than +35℃.
In atmospheric conditions, the air is clean and the relative humidity does not exceed 50% at a maximum temperature of +40°C. A higher relative humidity is allowed at lower temperatures, such as 90% at +20°C. However, considering the temperature changes, occasionally producing moderate condensation.
The altitude must not exceed 2000m.
This device is suitable for transportation and storage at the following temperatures: -25°C to 55°C, up to +70°C in a short period of time (no more than 24 hours). At these extreme temperatures, the device should be protected from any damage. irreversible damage and should function normally under normal conditions.
If the above conditions of use cannot be met, the user and manufacturer should negotiate to resolve the issue.
When this device is used on offshore oil drilling platforms and nuclear power plants, a separate technical agreement should be signed.
l MNS drawer cabinet technical parameters
1 Power distribution center (hereinafter referred to as PC)
The PC cabinet is divided into four compartments:
horizontal busbar compartment: at the rear of the cabinet; functional unit compartment: at the upper front or left side of the cabinet;
cable compartment: at The lower front part of the cabinet or the right side of the cabinet front; the control circuit compartment: in the upper front part of the cabinet;
separation measures: the horizontal busbar compartment, the functional unit compartment, and the cable compartment are separated by melamine phenolic flat core plates or steel plates.
The control circuit compartment and the functional unit compartment are separated by a flame-retardant polyurethane foam plastic molded cover.
The functional unit compartment on the left is separated from the cable compartment on the right by a steel plate.
2. The withdrawable electric control center and the small current power distribution center (hereinafter referred to as the withdrawable MCC) are
divided into three compartments, namely the horizontal busbar compartment at the rear of the cabinet and the functional unit on the left side of the front of the cabinet. compartment, the cable compartment on the right side of the front of the cabinet. The horizontal busbar compartment and functional unit compartment are separated by functional boards made of flame-retardant foam plastic, and the cable compartment is separated from the horizontal busbar compartment and functional unit compartment by steel plates.
3 Movable motor control center and small current power distribution center (hereinafter referred to as removable MCC)
3.1 The frame structure characteristics of the removable MCC are the same as those in 2.1 and 2.2.
3.2 The functional unit is designed as a removable structure. The connection between the functional unit and the vertical busbar adopts a primary isolation contact. Even if the circuit connected to it is live, the functional unit can be completely taken out and put back into the equipment. The other end It is a fixed structure.
3.3 The functional units of the removable MCC are divided into 8E/4, 8E/2, 8E, 16E, 24E, 32E and 40E. The total height of the functional unit compartment is also 72E.
4 busbar system
4.1 The horizontal busbar is installed in an independent busbar compartment behind the cabinet. It has two optional installation positions, namely one-third or two-thirds of the cabinet height. The busbar can be installed at the upper or lower part as needed, or The upper and lower groups can be installed at the same time, and the two groups of busbars can be used alone or in parallel. Each phase busbar consists of 2 or 8 busbars connected in parallel. The busbar cross-sections are 10×32×2, 10×60×2, 10×80×2, 10×60×4, 10×80×2×2 and 10× 60×4×2 six types.
4.2 Vertical busbar
The vertical busbar is an "L" type copper busbar of 50×30×5, which is embedded in a functional board made of flame-retardant plastic. The protection of live parts reaches IP20.
4.3 The neutral bus (N line) and neutral protection bus (PE line or PEN line) are installed parallel to the lower part of the functional unit compartment and vertically in the cable room. The N line is connected to the PE line. If the lines are separated by insulators, the N line and the PE line are used separately. If they are connected by a conductor, they become a PEN line.
l Structural features of MNS drawer cabinet
1. The frame of the MNS type low-voltage switch cabinet is a modular structure, and the basic skeleton is assembled from C-shaped steel. All structural parts of the cabinet frame are galvanized and are firmly connected to form a basic cabinet frame through self-tapping locking screws or 8.8 grade hexagonal bolts. Doors, partitions, mounting brackets, busbar functional units and other components corresponding to the changes in the plan are added for assembly. into a complete switch cabinet. The internal dimensions, component dimensions, and compartment dimensions of the switch cabinet all change according to the modularization (E=25mm).
2. Each cabinet of the MNS type combined low-voltage switch cabinet is divided into three rooms, namely the horizontal busbar room (at the rear of the cabinet), the drawer compartment (at the front of the cabinet), and the cable room (at the bottom of the cabinet or on the right side of the front of the cabinet). ). Rooms are separated from each other by steel plates or high-strength flame-retardant plastic functional boards. There are metal plates with ventilation holes between the upper and lower drawers to effectively prevent arcing caused by faults in the switch components or short circuits between the busbar and other circuits. caused accidents.
3. The structural design of the MNS type low-voltage switch cabinet can meet the requirements of various inlet and outlet schemes: top in and top out, top in and bottom out, bottom in and top out, bottom in and bottom out.
4. Compact design: accommodate more functional units in a smaller space
5. The structural parts are highly versatile and flexible in assembly. With E=25mm as the module, the structure and withdrawable units can be combined at will to meet the needs of system design.
6. The busbar is protected by high-strength flame-retardant and high-insulation-strength plastic functional boards, which have fault arc resistance and make operation and maintenance safe and reliable.
7. The mechanical interlocking mechanism of drawers of various sizes complies with standard regulations and has three obvious positions for connection, testing and separation, which is safe and reliable.
8. Adopt standard module design: it can be composed of standard units such as protection, operation, conversion, control, adjustment, measurement, and indication, etc., and can be assembled arbitrarily according to requirements.
9. The use of high-strength flame-retardant engineering plastics effectively enhances the protective safety performance.
10. High degree of generalization, standardization and easy assembly. With reliable quality assurance.
11. The cabinet can be selected with corresponding protection levels according to different requirements of the working environment.
12. Equipment protection continuity and reliability.