The single-front metal-enclosed switchgear KSO-272 is designed for operation in 6–10 kV systems to receive, distribute, and protect three-phase 50 Hz AC circuits. Typical applications include MV switchrooms at industrial plants and energy facilities, transformer substations, power stations, public-utility infrastructure, as well as factory-built modular indoor substations. The cubicle design emphasizes safe operation, service convenience, and straightforward integration into existing switchgear lineups.

Purpose and application

KSO-272 panels provide reliable power distribution and network protection against overloads and short-circuits. They are installed in 6–10 kV distribution bays and package transformer substations (PTS), at industrial power sites, in municipal power infrastructure, and other facilities. The universal construction suits both permanent switchrooms and rapidly deployable modular blocks. Standardized interfaces and a broad range of variants make the series suitable for new builds, refurbishments, and extension of existing lineups.

Service conditions

Standard environmental classification and location type - EN/IEC 60721-3-3 (stationary use at weather-protected locations, i.e., indoor). The base enclosure degree of protection is IP20 per IEC 60529, providing protection against access to hazardous parts and ingress of large solid objects. Options include increased IP ratings by compartment (e.g., IP31/IP41) with thermal checks, anti-condensation heaters, temperature/humidity sensors, filters/louvers, and micro-climate controllers. Versions with enhanced corrosion protection, vibration/seismic design, and dust/water-protected cable glands/entries are available.

Layout and construction

Two enclosure concepts are offered: (1) a welded steel frame with durable powder-polymer coating for maximum rigidity and lifecycle; (2) a bolted sheet-steel enclosure with Aluzinc (or zinc) coated panels for rapid assembly and clean joints. Each cubicle is subdivided into low-voltage (relay), apparatus/withdrawable, busbar, and cable compartments. Metallic partitions and earthed shutters prevent access to live parts during truck withdrawal. Busbars are copper or aluminum, with cross-sections and hardware rated for the declared short-time and peak withstand currents. The cable compartment includes convenient earthing points, cable cleats, shelves for CTs/VTs, and provisions for arc-flash sensors.

Primary equipment options include medium-voltage vacuum circuit-breakers (preferred), disconnectors and earthing switches with independent operating mechanisms, load-break switches, and combined switch-fuse units for transformer feeders. Instrument transformers (CTs/VTs) are selected to the required accuracy classes for protection and revenue metering; the series supports protection IEDs, metering panels, RTUs, and communication protocols such as Modbus RTU/TCP, IEC 60870-5-104, and IEC 61850/GOOSE. Breaker operations are performed with the HV door closed as a baseline safety principle.

Safety and interlocking

A coordinated system of mechanical and electrical interlocks prevents hazardous actions: blocking disconnector operation with the breaker closed; blocking earthing-switch closing when the disconnector is closed; blocking disconnector closing onto an earthed circuit; door interlocks tied to the earthing condition; and status indication via viewing windows and mechanical position indicators. On request, cubicles can be supplied with Internal Arc Classification (IAC) per IEC 62271-200 with accessibility class A and directions F/L/R (e.g., IAC AFLR 20 kA 1 s), with pressure-relief paths that discharge hot gases to a safe area or into a vent hood. Type-test scope and IAC marking are coordinated within the project and FAT/SAT programs.

Variants and options

KSO-272 can be configured as incomer, bus-section, and feeder bays; VT/CT and auxiliary-services panels; transformer feeders; and metering bays. Options include microprocessor protection and automation with O/C (instantaneous & time-delay), earth-fault, neutral-displacement, autoreclose and automatic transfer; integration into SCADA/DCS; enhanced anti-corrosion systems; thermal insulation and space heaters; retrofit interfaces to existing series via transition panels; and digital add-ons (arc/temperature sensors, position readers, IEC 61850/GOOSE). Comparable IEC-type MV panels in the market demonstrate similar door-closed operation, IAC AFLR performance, and LSC 2B / PM partitioning for service continuity.

Typical configurations

Common schemes include incomers and bus-sectionalizers, outgoing feeders, VT panels, and auxiliary-services panels. Customer-specific single-bus and double-bus arrangements (with bypass bus where required) are supported, including containerized PTS layouts with ventilation and arc-gas exhaust.

Standards and compliance

KSO-272 is engineered and manufactured in line with applicable international standards for medium-voltage switchgear (final lists are project-specific):

• IEC 62271-200 - Metal-enclosed switchgear and controlgear 1–52 kV, including internal-arc classification (IAC), LSC/partition classes, type & routine tests.
• IEC 62271-1 - General requirements (service conditions, insulation levels, electrical & mechanical tests).
• IEC 62271-100 - AC circuit-breakers.
• IEC 62271-102 - Disconnectors and earthing switches.
• IEC 62271-103 - Switches and switch-disconnectors.
• IEC 62271-105 - AC switch-fuse combinations.
• IEC 60529 - Degrees of protection (IP Code).
• EN/IEC 60721-3-3 - Environmental classes for stationary use at weather-protected locations (indoor).
• IEC 61869-2/-3 - Instrument transformers (CTs/VTs) for protection & metering.
• IEC 60071-1/-2 - Insulation coordination (power-frequency & impulse withstand levels).
• IEC 61936-1 - Power installations exceeding 1 kV AC (design & erection rules).
• IEC 62271-202 - AC prefabricated substations (for containerized/block-substation use).

Partnering with manufacturers and producers

We cooperate with switchgear/component manufacturers, engineering & installation contractors, and investors interested in localizing KSO-272 production. We provide complete technical support packages: transfer of design/manufacturing documentation, training for design and process engineers, first-series (pre-series) support, site audits, FAT/SAT programs and interlock-test methods, and assistance with type-test programs and certification protocols. For regional markets, we align designs to local codes, select components with suitable logistics, and agree labeling and documentation languages.

Documentation offered

For KSO-272, we supply a complete set of design and manufacturing documents: tender-stage drawings and data sheets; detailed working drawings; and 3D models in AutoCAD (DWG), SolidWorks, DXF, STEP, IGES, and Parasolid formats. Project-specific adaptations are available to reflect your production capabilities. Our documentation streamlines integration of new equipment with existing substations and supports rapid series launch without pilot prototypes.

Technical data

Why partner with us

We support the full project cycle - from technical documentation to production consulting. You receive a complete, production-ready document set usable by mid-level engineers. Thanks to a library of proven modules and repeatable solutions, serial manufacturing can begin immediately after design approval, without pilot prototypes. Our experts provide guidance across manufacturing and commissioning, including protection IED setup, interlock verification, preparation of FAT/SAT, and O&M documentation.

For additional information on KSO-272 please contact: inbox@proekt-energo.com

As practice shows, design-stage errors multiply fabrication and lifecycle costs; we help minimize these risks through careful device specification, correct instrument-transformer selection, and robust busbar design.

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