ЩСН - personal needs shield

ЩСН

They are used to supply energy to equipment in auxiliary systems (lighting, heating, switch drives, pumps, etc.) with alternating current of 0.4 kV.

Purpose:

The switchboards are designed for input and distribution of 0.4 kV 50 Hz electric power to power consumers of auxiliary needs of power facilities (35-750 kV electric substations, power plants, industrial enterprises, etc.). The 0.4 kV switchboards are developed and manufactured in accordance with modern requirements for single-line diagrams of the Customer, taking into account the requirements for service safety. The switchboards ensure reliable power supply of auxiliary consumers with alternating current of 0.4 kV, implement selective protection of inputs and outgoing feeders, and provide automatic power switching (APS) of consumers according to an explicit or implicit backup scheme.

Design features:

The design of the ЩСН board is made in the form of prefabricated cabinets made of galvanized steel or welded cabinets. Upon request, ЩСН are made in an earthquake-resistant design up to 9 points according to MSK-64.
ЩСН are manufactured in the form of cell-type boards with withdrawable, plug-in or stationary automatic circuit breakers of both domestic and imported production.
ЩСН can be connected to one or two transformers (other options are possible) with a capacity of 63 kVA to 2500 kVA. It is possible to place the board in one or two rows. In the case of a two-row design, the boards can additionally be equipped with a busbar bridge. All options are implemented according to the methods of supplying buses or cables
. Maintenance of cabinets: one- or two-way.
Secondary switching circuits are laid in cable boxes.
The ЩСН board consists of:

• Input cabinets;
• Sectional cabinets;
• Outgoing line cabinets;

Control and automation cabinets.

The shields for own needs provide:

• Receiving alternating current electricity;
• Distribution of electricity between consumers;
• Protection of consumers and outgoing lines from short-circuit and overload currents using automatic switches;
• Automatic activation of the ATS when voltage drops at one of the inputs.

Auxiliary circuit equipment:

Auxiliary devices of the ЩСН are powered from the operational power supply circuits. Depending on the requirements for the ЩСН, which are determined by the design organization and specified when ordering, power can be supplied from:

• 220 V DC circuits from the DC switchboard (DCS);
• 220 V 50 Hz AC circuits - generated from the switchboard sections or from an external uninterruptible power supply.

To ensure automation and control functions in the control center, the following devices are used:

• automatic control circuit breakers;
• voltage control relay;
• time relay;
• intermediate relays;
• current transformers.

For visual control of network parameters, indication and control, the following are placed on the switchboard doors:

• ammeters;
• voltmeters;
• switches;
• indicator lamps;
• control buttons.

Control of input and section switches can be carried out in one of 3 modes:

• automatic, when control is provided by the ATS logic;
• manual - by local manual controls;
• remote - commands from the automated process control system (remote control).

Distinctive features of the SHCH:

• Maximum factory readiness of the product.
• Possibility of installing equipment of various types and compositions in accordance with the Customer’s requirements.
• Ease of installation and operation.
• Possibility of connection from both the bottom and the top.

Operating conditions of the SHCHN:

Climatic version and placement category of the SHCHN — U3 according to GOST 1515-69.
SHCHN cabinets are intended for indoor use under the following conditions.

• ambient air temperature from +5°С to +40°С;
• the environment is explosion-proof, does not contain dust, including conductive dust, aggressive vapors and gases in concentrations that destroy metal and insulation;
• group of operating conditions in terms of environmental impact according to GOST 17516.1-90 – M2;
• relative air humidity up to 80% at a temperature of 20ºС according to GOST 15543.1-89
• installation altitude above sea level - no more than 2000 m (when operating panels at an altitude of more than 1000 m, the characteristics of the devices used in the panels must be reduced in accordance with GOST 15150-69);
• working position in space – vertical, deviation from the vertical position of up to 5° in any direction is allowed;
• degree of protection of the SHCHN IP31 according to GOST 14254-96;

seismic resistance - 6 points (up to 9 points can be made to order) according to MSK-64

Technical characteristics of the SHSN auxiliary cabinet:

For KTP with transformers of different voltage classes, differing only in the nominal voltage of the HV windings with the same weight, overall and installation dimensions and price, the largest of the voltage classes of the HV windings of these transformers is indicated. An example of the conventional designation of the KTP type with a capacity of 400 kVA, voltage class of 10 kV for a nominal voltage on the LV side of 0.4 kV, year of development 1982, climatic version HL, placement category 1: KTP-400/10/0.4-82-HL1