Single-front metal-enclosed switchgear 6–10 kV, type KSO-205, is intended for the reception and distribution of three-phase AC power at 50 Hz in networks with isolated or effectively earthed (grounded) neutral. The switchgear belongs to the class of medium-voltage metal-enclosed assemblies designed for long, safe operation as part of indoor switchgear (indoor substations), package transformer substations, and other power-supply facilities. The design focuses on high serviceability and rapid replacement of withdrawable units without extended downtime.

Typical applications of KSO-205:
- indoor switchgear of package transformer substations (prefabricated substations);
- substations of industrial facilities;
- auxiliary switchgear of power plants;
- municipal utilities;
- distribution points, supply centers, and sectioning nodes of urban and industrial networks;
and other power-supply installations.

KSO-205 panels can be installed both in permanent indoor substation buildings and in special factory-built modular enclosures. Each panel is a bolted/riveted sheet-metal structure made of hot-dip galvanized folded steel. KSO-205 provides single-front service with single-row or back-to-back layouts. A panel with a vacuum circuit-breaker features segregated compartments: low-voltage (relay) compartment, withdrawable unit compartment, busbar compartment, and cable compartment.

The relay compartment, the withdrawable unit compartment, and the cable compartment are closed by separate doors keyed alike. The relay compartment is segregated from primary circuits; protection and automation equipment is mounted inside and on its door. As withdrawable units the panels may use: a vacuum circuit-breaker; a sectionalizing disconnector; a voltage-transformer truck.

The withdrawable unit can be set to the following positions relative to the enclosure: service, test, and maintenance. In the service position, both main and auxiliary circuits are engaged and the unit is latched within the panel. In the test position, the main circuits are disconnected while auxiliary circuits remain engaged (disconnection of auxiliaries is permissible); the unit is fixed within the panel. In the maintenance position, both main and auxiliary circuits are disconnected and the unit is placed outside the panel on a service trolley.

The KSO-205 incorporates the following interlocks:
- an interlock preventing movement between service and test positions with the circuit-breaker closed;
- an interlock preventing circuit-breaker closing in the intermediate position (between service and test);
- an interlock preventing racking in/out of a unit with plug-in contacts under load;
- an interlock preventing racking from test to service with the earthing (grounding) switch closed;
- an interlock preventing closing of the earthing switch in service or intermediate positions (i.e., allowed only in the test position);
- a cable-compartment door interlock preventing door opening when the earthing switch is open;
- a door interlock on panels with a load-break switch preventing door opening when the earthing switch is open.

Purpose and application

KSO-205 panels are intended for reception, distribution, and switching of 6–10 kV electrical energy in power-supply systems of industrial, infrastructure, and energy facilities. Typical functions include: incoming and bus sectioning, outgoing feeders (cable and overhead), transformer feeders, capacitor banks, technological drives, as well as commercial and technical metering points. The panels support protection and automation functions (e.g., instantaneous/time overcurrent, earth-fault, autoreclosing, automatic transfer) and integration into SCADA/DCS via standard interfaces and protection relays (IEDs).

Service conditions

Standard environmental category - per EN/IEC 60721-3-3 (indoor, naturally ventilated locations in temperate climates). Enclosure degree of protection - IP31 to IEC 60529, providing protection against solid objects ≥ 2.5 mm and vertically falling drops of water. On request, increased degrees of protection can be provided for individual compartments (e.g., IP41/IP54), along with filters/louvered inlets, space heaters, and micro-climate sensors. Options are available for vibration and seismic performance, anti-corrosion finishes, and enhanced dust/moisture protection for special regions.

Layout and construction

The panel follows a modular concept with functional segregation into compartments: low-voltage (relay), withdrawable unit, busbar, and cable. Metal partitions/screens and mechanical shutters prevent access to live parts when the withdrawable unit is removed. Primary circuits are made with copper or aluminium busbars (bus ratings of 630/1000/1600 A depending on configuration); joints are designed for the short-time thermal and dynamic currents specified in the data table. The mounting framework uses perforated profiles to simplify installation of secondary wiring, current/voltage transformers, terminal blocks, and temperature/arc sensors.

Primary apparatus include vacuum circuit-breakers with mechanical/electrical endurance suitable for 6/10 kV distribution duty, as well as disconnectors, earthing switches, load-break switches, and combined switch-fuse units for the protection of small and medium-power transformers. Instrument transformers are applied per IEC 61869-2/-3 (or national harmonized standards), ensuring correct operation of metering devices and protection IEDs.

Safety and interlocking

Comprehensive safety is achieved through a combination of design measures and interlocks: mechanical (cam/lever mechanisms, key interlocks), electrical (limit switches, interlock circuits), and organizational (keyed access, labeling, safety signage). Viewing windows provide visual indication of the circuit-breaker and earthing-switch positions, as well as shutter and door status. On request, panels can be supplied with internal arc classification (IAC) with accessibility classes AFL/AFR/AFLR in accordance with IEC 62271-200; this option vents arc energy and by-products through pressure-relief systems to reduce risks to personnel and equipment.

Versions and options

The KSO-205 range covers incoming, bus-section, and feeder panels; transformer and capacitor-bank feeders. Options include: metering compartments with commercial metering nodes; switch-fuse combinations (for transformer protection 250–1600 kVA); sectionalizing devices with remote control; arc-flash sensors and fast trip devices; auxiliary power and DC panels; communication interfaces (Modbus, IEC 60870-5-104, IEC 61850) for dispatching; busbar redundancy; bus bridges and switchgear extensions. Supply as part of prefabricated modular substations (containerized indoor switchgear) is available in accordance with IEC 62271-202.

Typical configurations

• Incoming/bus section - panels with a vacuum circuit-breaker or disconnector, current transformers for overcurrent/power protections, with the option to implement ATS/AR.
• Feeder panel - withdrawable circuit-breaker, CTs/VTs, relay compartment with protection IED (IOC/TOC, definite-time/IDMT, earth-fault), terminals for 6–10 kV cable connections.
• Transformer feeder - switch-fuse combination (or circuit-breaker with protection), VT for metering on the MV side, personnel earthing switch.
• Metering cubicle - withdrawable VT truck, metering cabinet, interfaces for AMR/AMI systems.
• Bypass/transfer - for bypassing lines/equipment during maintenance, fitted with disconnectors and mechanical interlocks.
• Module for prefabricated substation - integration of multiple KSO-205 panels into a containerized solution with appropriate ventilation, heat removal, and fire-safety measures.

Compliance with standards

Design and manufacture of KSO-205 follow international and harmonized standards applicable to medium-voltage metal-enclosed switchgear. Key references include:

• IEC 62271-200 - AC metal-enclosed switchgear and controlgear for 1–52 kV (incl. internal-arc classification, IAC).
• IEC 62271-100 - AC circuit-breakers.
• IEC 62271-102 - AC disconnectors and earthing switches.
• IEC 62271-105 - Switch-fuse combinations for 1–52 kV.
• IEC 62271-202 - Prefabricated substations for AC 1–52 kV (for containerized solutions).
• IEC 60529 - Degrees of protection (IP Code).
• EN/IEC 60721-3-3 - Environmental conditions for weather-protected stationary use (replaces GOST 15150 U3).
• IEC 61869-2/-3 - Instrument transformers (CTs and VTs) for measurement and protection.
• IEC 60071-1 - Insulation coordination: selection of withstand voltage levels for switchgear above 1 kV.

Technical data

We offer documentation to manufacture KSO-205:

- Preliminary technical documentation for tender participation to manufacture KSO-205. We will prepare the information needed to assess feasibility against tender requirements and data sheets.
- Detailed fabrication package: working drawings, 3-D models, and all materials required to manufacture KSO-205 at your facility. If you do not plan to produce parts in-house, we will help outsource their fabrication. Final assembly and wiring are performed at your site.
- All documentation can be adapted to project requirements and to your plant’s manufacturing capabilities.
- If your substation has equipment from another manufacturer, we will prepare documentation to produce compatible panels to complement the existing installation.

Deliverables and files

• Design and fabrication sets: schematic diagrams, single-line diagrams, wiring diagrams, cable schedules, BOMs and parts lists.
• 3D models and assemblies: SolidWorks (SLDPRT/SLDASM), Parasolid (x_t/x_b), STEP, IGES - for BIM/PLM integration.
• Drawings and flat patterns: AutoCAD (DWG), DXF - for laser/punch cutting and sheet-metal bending.
• Protection & control settings and configurations: relay IED settings, HMI templates, IEC 60870-5-104/IEC 61850 protocols.
• Installation & commissioning manuals, interlock check procedures, and FAT/SAT functional test programs.

Partnering with subcontractors

We welcome cooperation with manufacturers of electrical equipment, metal structures and LV panels, with engineering and installation companies, and with investors interested in localizing production of KSO-205 panels. Support packages include transfer of design/technical specifications, training for technologists and designers, support of initial series, production process audits, and assistance with certification tests. For regional markets we can align with local norms and standards, prepare type-test programs and FAT/commissioning procedures, and select components with favorable logistics.

Your benefits:

- No need to maintain a large team of highly qualified engineering staff - you receive a complete documentation set that can be executed by mid-level engineers.
- No need to build prototypes - our experience enables immediate serial production, reducing time-to-market.
- Working to our documentation, your specialists receive consulting on all nuances of KSO-205 manufacturing, including protection relay commissioning and interlock verification, FAT/SAT programs, and preparation of operation manuals.

For more information on KSO-205 contact: inbox@proekt-energo.com

…and, as is well known, an error made at the design stage costs 10× in manufacturing and 100× in operation.

PDF - Download KSO-205 technical information