Single-front metal-enclosed switchgear 6–10 kV KSO-219 is intended for the reception, distribution and switching of three-phase 50 Hz AC power in networks with isolated, compensated or effectively earthed (grounded) neutral. KSO-219 belongs to the class of medium-voltage metal-enclosed switchgear designed for long service life, easy maintenance/retrofit, and safe operation of personnel without de-energizing adjacent feeders when standard interlocks and procedures are observed.

Typical applications of KSO-219:
- indoor switchgear (indoor substations) of package transformer substations (prefabricated substations);
- substations of industrial facilities and infrastructure sites;
- auxiliary switchgear of power plants;
- municipal utilities (water, district heating, urban infrastructure);
- distribution points, supply centers and sectioning nodes of urban and industrial networks;
and other power-supply installations.

KSO-219 panels can be installed both in permanent indoor substation buildings and in special factory-built, rapidly deployable modules. Distinctive features of KSO-219:
- two main enclosure concepts: (1) welded carbon-steel frame with polyester powder coating; (2) aluminium-zinc (galvanized) coated sheet-steel with riveted/bolted joints - for enhanced corrosion resistance and maintainability;
- closed-door operation for all circuit-breaker manipulations; front viewing windows provide visual status of the primary switching devices;
- mechanical and electrical interlocks eliminate hazardous operations (see the “Safety and interlocking” section);
- internal lighting in every panel; receptacles for portable lamps and a light switch are brought to the front; lamp replacement is allowed without de-energizing main and auxiliary circuits;
- docking with other KSO family panels (e.g., KSO-2) via transition panels, facilitating step-by-step modernization of existing switchgear.

Purpose and application

KSO-219 is used to build incoming, bus-section and feeder connections of 6–10 kV distribution networks, to supply power transformers, distribute energy over cable and overhead lines, connect reactive-power compensation banks, process drives and special loads. The cubicles provide integration of protection and control IEDs (instantaneous/time overcurrent, earth-fault, sensitive earth-fault, autoreclosing, automatic transfer, etc.), organization of commercial and/or technical metering, and dispatching (SCADA/DCS) via standard communication interfaces. Owing to its block-modular architecture, KSO-219 scales easily within indoor switchgear/packaged substations, supports section extensions, bus bridges and temporary bypass schemes for maintenance.

Service conditions

Base environmental category - EN/IEC 60721-3-3 (weather-protected stationary use indoors with natural ventilation in temperate climates). Default enclosure degree of protection - IP20 to IEC 60529 (protection against finger/tool access to hazardous parts and ingress of specified solid objects). Where required, individual panels/compartments can be supplied with higher degrees of protection (e.g., IP31/IP41) considering heat dissipation and convection.
Optional extensions cover a wider range of conditions: anti-condensation space heaters, temperature/humidity sensors, filter-fan units, corrosion-resistant versions, dust-/moisture-sealed cable entries, as well as vibration- and seismic-resistant solutions. Selection and application of degrees of protection follow IEC 60529 (IP Code); environmental categories follow EN/IEC 60721-3-3 (see Standards below).

Layout and construction

The internal layout of KSO-219 is based on functional segregation into compartments: low-voltage (relay), apparatus/withdrawable unit (depending on design - drawout circuit-breaker, load-break switch, disconnector, or switch-fuse combination), busbar and cable. Inter-compartment partitions, metal shutters and insulating screens prevent access to live parts when the apparatus is racked out. Contact systems are rated for the declared short-circuit thermal and dynamic stresses; primary busbars are copper or aluminium with cross-sections sized for the specified currents (see the “Technical data” table).

The relay compartment is segregated from primary circuits and houses protection IEDs, measuring instruments, telemetry modules, terminal blocks and DC auxiliary power sources. The cable compartment provides dedicated earthing (grounding) points, brackets for cable fixing and space for current/voltage transformers. The layout minimizes arc volumes, provides directed gas exhaust for abnormal conditions, and ensures easy access for routine maintenance.

Safety and interlocking

The safety concept combines mechanical and electrical interlocks that prevent incorrect operations and access to live parts:
- blocking of disconnector operations with the circuit-breaker closed;
- blocking of disconnector closing with the earthing (grounding) switch closed;
- blocking of earthing-switch closing with the disconnector closed;
- door interlocks (including blocking of door opening when the earthing switch is open);
- circuit-breaker operations permitted only with the panel door closed (closed-door operation);
- visual position indication of devices through viewing windows and mechanical indicators;
- electrical interlock circuits via limit switches, key-interlocks and shutter-position monitoring devices.

On request, panels can be supplied with internal arc classification (IAC) with accessibility class (A) and directions (F/L/R - front/side/rear) for specified current/time (e.g., IAC AFLR 20 kA 1 s). Requirements for internal arc protection and test methods are defined in IEC 62271-200 for AC metal-enclosed switchgear 1–52 kV.

Versions and options

• Incoming/backup/bus-section - circuit-breaker or disconnector, bus-coupler modules, implementation of automatic transfer/autoreclosing and bus sectioning.
• Outgoing feeder - drawout circuit-breaker, CTs/VTs, protection IED (IOC/TOC/SEF/EF), metering and telemetry.
• Transformer feeder - switch-fuse combination or circuit-breaker + protection IED; gR/aR fuses selected to transformer rating.
• Metering/measurement cubicle - drawout VT truck, commercial metering cabinet, interfaces for AMR/AMI systems.
• Reactive-power compensation - capacitor-bank feeder with appropriate switching and protections.
• Digital options - arc-flash sensors, temperature sensors on busbars/contacts, integration via Modbus RTU/TCP, IEC 60870-5-104, IEC 61850 (GOOSE).
• Enhanced enclosure protection - selected panels at IP31/IP41, versions for aggressive environments, seismic-rated fixings.

Instrument transformers are applied in accordance with the IEC 61869 series (Part 2 - current transformers, Part 3 - voltage transformers), ensuring correct operation of metering and protection functions.

Typical configurations

• Single-section busbar system with one incoming feeder and a group of outgoing feeders; line or transformer backup can be implemented.
• Two-section busbar system with a bus-section circuit-breaker and automatic transfer on incomers; bus bridges between switchboards are possible.
• Bypass bus arrangement - enabling maintenance of feeders without service interruption.
• Module for packaged substation - a set of KSO-219 panels in a climate-controlled container with gas relief, ventilation and micro-climate subsystems per IEC 62271-202.
• Commercial metering node - dedicated cubicle with VTs/CTs and metering cabinet, integration with AMR/AMI and upper-level systems.

Compliance with standards

Design, manufacture and testing of KSO-219 follow applicable international and harmonized standards for 6–10 kV medium-voltage switchgear. Key references include:

• IEC 62271-200 - AC metal-enclosed switchgear and controlgear for 1–52 kV; defines internal-arc classification (IAC) and test methods.
• IEC 62271-1 - Common specifications for high-voltage (MV/HV) switchgear and controlgear.
• IEC 62271-102 - AC disconnectors and earthing switches.
• IEC 62271-103 - AC switches for rated voltages above 1 kV and up to and including 52 kV.
• 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 provided by enclosures (IP Code).
• EN/IEC 60721-3-3 - Environmental conditions - classification 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 equipment above 1 kV.

Technical data

We offer documentation to manufacture KSO-219:
- Preliminary technical documentation for tender participation: single-line solutions, equipment lists, short-circuit current calculations, data sheets, explanatory notes, delivery schedules and risk maps.
- A complete “production-ready” working package for organizing manufacturing at your facility: specifications, lists of purchased components, assembly drawings, sheet-metal flat patterns and bend tables, connection and wiring diagrams, cable schedules, protection-settings tables, FAT/SAT test programs.
- If you lack in-house sheet-metal cutting/bending capability, we assist with cooperation: selection of metalworking, powder-coating and plating subcontractors, procurement of cabinet hardware and busbar fittings, supply of primary and secondary devices with factory certificates.
- Adaptation of documentation to project requirements, national norms and your technological capabilities (tooling, tolerances, coatings, steel grade, batch size), support of initial series and personnel training.

Why work with us

- No need to maintain a large team of highly qualified engineers: you receive a complete documentation set that a mid-level engineer can execute when following the instructions.
- Faster time-to-series: our libraries of standard subassemblies and proven solutions enable batch launch with few or no prototypes.
- Technology support: consulting on protection-relay commissioning, interlock verification, configuration of communication protocols (Modbus/IEC 60870-5-104/IEC 61850), preparation of FAT/SAT programs, as well as operation, maintenance and retrofit (e.g., replacing circuit-breakers and actuators on existing trucks without changing the enclosure).

Partnering with contractors and investors

We are open to cooperation with manufacturers of electrical apparatus and metal structures, design and installation companies, and investors interested in localizing production of KSO-219. We provide: production audits, process qualification, assistance in preparing for type and routine tests, certification support, development of training programs and operating documentation packages. For regional markets we align local requirements (marking, documentation language, environmental category, IP selection) and substitute components with logistically available equivalents without loss of functionality or safety.

Deliverables and files

• 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 cutting, stamping and sheet-metal bending.
• Secondary-circuit packages: schematic and wiring diagrams, terminal/wire tables, telecontrol signal lists, HMI templates.
• Protection IED configurations and exchange files (CID/SCD) for IEC 61850, settings for IEC 60870-5-104/Modbus, settings protocols and test reports.
• Installation & commissioning manuals, interlock and arc-protection test procedures, FAT/SAT programs and checklists.

For more information on KSO-219 contact: inbox@proekt-energo.com

…and, as is well known, an error made at the design stage costs ten times more in manufacturing and a hundred times more in operation.

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