MNS type low-voltage complete switchgear

MNS-type low-voltage complete switchgear is used in power distribution systems of power plants, petroleum, chemical, metallurgy, textile, high-rise buildings and other industries. In large-scale power plants, petrochemical systems and other high degree of automation, the requirements of the place of interface with the computer, as a three-phase AC frequency of 50 (60) Hz, the rated operating voltage of 380V (400), (660), the rated current of 5000A and the following power generation system in the power distribution, centralized control of motors, reactive power compensation of the use of low-voltage power distribution equipment.
Model Meaning

Structural characteristics

The basic cabinet frame of this device is a combination of assembled structure, all the structure of the frame is galvanized, the cabinet adopts the combination of assembled structure of C profile, the C profile is made of high-quality cold-rolled steel plate bending with modulus mounting holes of E-25mm, which is connected to each other by self-tapping locking screws and 8.8 hexagonal screws to form the basic cabinet frame, and then according to the needs of the program changes, together with the corresponding doors, sealing plates, partitions, mounting Bracket and busbar, functional units and other parts, assembled into a complete low-voltage switchgear cabinet, switchgear cabinet parts size, compartment size implementation of modular (modulus unit E = 25m, the same below).

Power distribution center (hereinafter referred to as PC)

PC cabinet is divided into four compartments, i.e., horizontal busbar compartment, at the rear of the cabinet: functional unit compartment, at the upper front of the cabinet or the left side of the front of the cabinet: cable compartment, at the lower front of the cabinet or the right side of the front of the cabinet; control circuit compartment, at the upper front of the cabinet.

Withdrawable motor control center and small current power distribution center (hereinafter referred to as withdrawable MCC): the withdrawable MCC cabinet is divided into three isolation compartments, namely, the horizontal busbar compartment at the rear of the cabinet, the functional unit compartment at the left side of the front of the cabinet, and the cable compartment at the right side of the front of the cabinet. The horizontal busbar compartment is separated from the functional unit compartment by a functional biscuit made of flame retardant foam. The cable compartment is separated from the horizontal busbar compartment and the functional unit compartment by a steel plate. There are two types of cable outlet: rear outlet and side outlet.

There are five standard sizes of drawers in the pull-out MCC, namely, 8E/4, 8E/2, 8E, 16E and 24E, of which 8E/4 and 8E/2 drawers are constructed with molded flame-retardant plastic parts and aluminum alloy profiles (four 8E/4 or two 8E/2 to form an 8E height compartment). The height of the functional unit compartment is 72E.

Busbar system

The horizontal busbar is installed in a separate busbar compartment at the rear of the cabinet, which has two selectable installation positions, at 1/3 or 2/3 of the cabinet height. The busbar can be installed in the upper or lower part as required, or the upper and lower groups can be installed at the same time. The two groups of busbars can be used individually or side by side.

Each group of busbar consists of 2, 4 or 8 busbars connected in parallel, and the cross section of busbar consists of six kinds: 10*30*2, 10*60*2, 10*80*2, 10*60*4, 10*80*2*2 and 10*60*4*2.

The vertical busbar is a 50*30*5 L-type copper busbar, which is embedded in a functional wall made of flame retardant plastic, and the protection level of the electrified part is up to IP20.

Neutral wire (N wire) and protective ground wire (PE wire). Neutral and protective earthing busbars are installed in parallel in the lower part of the functional unit compartment and in the cable compartment in a straight line.If the N and PE wires are separated by insulators, then the N and PE wires are used separately, and if the two are shorted by a conductor, then they become PEN wires.