In order to meet the needs of the development of the power industry, the MNS low-voltage pull-out switchgear (hereinafter referred to as the switchgear) is an advanced low-voltage switchgear designed and improved by referring to foreign MNS series low-voltage switchgear. The product conforms to the national standards GB7251, VDE660 and ZBK36001-89 "low-voltage withdrawable switchgear", the international standard IEC439 provisions of MNS type low-voltage switchgear to meet the needs of various power supply, distribution, can be widely used in power plants, substations, industrial and mining enterprises, buildings, hotels, municipal construction and other low-voltage distribution systems.

MNS Chest of drawers Conditions of use

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

In atmospheric conditions, 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 lower temperatures, such as 90% at +20 ° C, but taking into account the occasional moderate condensation due to temperature changes.

The altitude must not exceed 2000m.

The device is suitable for transport and storage at temperatures ranging from -25 ° C to 55 ° C, up to +70 ° C for a short period of time (not more than 24h), at these limit temperatures the device shall avoid any irreparable damage and shall be able to operate normally under normal conditions.

If the above conditions of use cannot be met, it shall be resolved by negotiation between the user and the manufacturer.

When the device is used on offshore oil drilling platforms and nuclear power plants, a separate technical agreement shall be signed.

l MNS drawer technical parameters

1 Power Distribution Center (hereinafter referred to as PC)

The PC cabinet is divided into four compartments:

Horizontal bus compartment: at the rear of the cabinet; Functional unit compartment: on the upper or left side of the front of the cabinet;

Cable compartment: in the lower part of the cabinet or the right side of the cabinet; Control loop compartment: in the upper part of the front cabinet;

Separation measures: The horizontal bus compartment, the functional unit compartment and the cable compartment are separated by melamine phenolic flat core board or steel plate.

The control loop compartment and the functional unit compartment are separated by a flame-retardant polyurethane foam moulded cover.

The functional unit compartment on the left is separated from the cable compartment on the right by a steel plate.

2 Withdrawable electric control center and small current power distribution center (hereinafter referred to as withdrawable MCC)

The withdrawable MCC cabinet is divided into three compartments, namely, the horizontal bus compartment at the rear of the cabinet, the functional unit compartment on the left side of the front of the cabinet, and the cable compartment on the right side of the front of the cabinet. A functional board made of flame-retardant foam plastic is used to separate the horizontal bus compartment from the functional unit compartment, and a steel plate is used to separate the cable compartment from the horizontal bus compartment and the functional unit compartment.

3 Movable motor control center and small current power distribution center (hereinafter referred to as movable MCC)

3.1 The frame structure features of the removable MCC are the same as those of 2.1 and 2.2.

3.2 The functional unit is designed to be a movable structure, and the connection between the functional unit and the vertical bus adopts a single isolation contact. Even if the circuit connected to it is charged, the functional unit can be completely removed from the device and put back into the device, and the other end is a fixed structure.

3.3 The functional units of the mobile MCC are divided into 8E/4, 8E/2, 8E, 16E, 24E, 32E and 40E. The total height of the functional unit compartments is also 72E.

4 Bus system

4.1 The horizontal bus bar is installed in the independent bus compartment at the back of the cabinet, and it has two optional installation positions, that is, one third or two thirds of the cabinet height. The bus bar can be installed in the upper or lower part as required, or two groups of upper and lower bus bars can be installed simultaneously. The two groups of bus bars can be used separately or in parallel. Each phase bus bar consists of 2 or 8 busbars in parallel, and the bus bar section has six kinds of 10×32×2, 10×60×2, 10×80×2, 10×60× 4,10 ×80×2 and 10×60×4×2.

4.2 Vertical bus bar

Vertical bus 50 x 30 x 5 "L" type copper bus, which is embedded in a function board made of flame retardant plastic. Protection of live parts up to IP20.

4.3 Neutral Bus (N wire) and neutral protection bus (PE wire or PEN wire) The neutral bus and neutral protection bus are installed parallel to the lower part of the functional unit compartment and vertically in the cable room. If the N wire and PE wire are separated by an insulator, the N wire and PE wire are used separately. If the two are connected by a conductor, the PEN wire is formed.

l MNS drawer structure features

1. MNS type low-voltage switchgear frame is a combined structure, and the basic skeleton is assembled by C-type steel. All the structural components of the cabinet frame are galvanized and securely connected to the basic cabinet frame by self-tapping locking screws or 8.8-level hexagon bolts. The cabinet is assembled into a complete switch cabinet with doors, partitions, mounting brackets, and bus function units corresponding to the change of the solution. The internal size of the switch cabinet, the size of the parts and the size of the compartment are changed according to the modularization (E=25mm).

2. Each cabinet of MNS type combined low-voltage switchgear is divided into three rooms, namely, the horizontal bus room (in the back of the cabinet), the drawer room (in the front of the cabinet), and the cable room (in the lower part of the cabinet or the right side of the cabinet). The room is separated from the room by steel plate or high-strength flame-retardant plastic function board, and the metal plate with ventilation hole is isolated between the upper and lower drawers to effectively prevent the flarc caused by the fault of the switch element or the accident caused by the short circuit of the bus and other lines.

3. The structural design of MNS type low-voltage switchgear can meet the requirements of various inlet and outlet lines: upper inlet and lower outlet, upper inlet and lower outlet, and lower inlet and lower outlet.

4. Compact design: Accommodate more functional units in a smaller space

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

6. The bus bar is protected by the high-strength flame-retardant and high-insulation plastic functional board, which has the performance of anti-fault arc, making the operation and maintenance safe and reliable

7. The mechanical interlocking mechanism of various sizes of drawers meets the standard provisions, and there are three obvious positions of connection, test and separation, which are safe and reliable.

8. Standard module design: can be composed of protection, operation, conversion, control, adjustment, measurement, indication and other standard units, can be arbitrarily assembled according to requirements.

9. The use of high-strength flame-retardant engineering plastics, effectively strengthen the protection and safety performance.

10. High degree of universality, standardization, convenient assembly. With reliable quality assurance.

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

12. Continuity and reliability of equipment protection.