K-47 Outdoor Medium-Voltage Metal-Clad Switchgear

The KRUN K-47 is a modular outdoor metal-clad switchgear lineup for receiving, metering, and distributing three-phase AC, 50 Hz, at 6 and 10 kV. Typical applications include plant auxiliary switchgear at power stations, distribution nodes of utility substations, power supply for industrial and mining sites, agricultural facilities, oil & gas infrastructure, and municipal utilities. Conceptually, K-47 follows a proven cell architecture with built-in drawout elements, a walk-in control corridor, and relay cabinets, ensuring standardized layouts, convenient maintenance, and scalability as the network grows.

Purpose and Application

The KRUN K-47 is intended for 6–10 kV substation switchgear: line sectionalizing and connection of overhead/cable feeders, supply of station auxiliaries (via an SST cabinet), as well as connection of power transformers and medium-voltage loads. In a typical substation bay cluster, K-47 performs the roles of incoming feeder, sectionalizing, switching of outgoing feeders, measurement and revenue metering, operational automation, AR/ATS (auto-reclosing/automatic transfer), and telecontrol. The equipment provides overload and short-circuit protection, selectivity, high maintainability (drawout primary apparatus), and compatibility with modern protection and control IEDs.

The basic purpose and functional/layout principles align with established 6–10 kV MV switchgear practice: cell-based structure with segregated compartments, walk-in control corridor, drawout trolleys with vacuum circuit breakers or isolating contacts, independent pressure-relief paths, and internal-arc containment. These solutions are described in industry guidance for MV switchgear and meet the requirements of IEC/EN practice.

Technical Data

Rated voltage, kV	6; 10
Highest voltage for equipment (Um), kV	7.2; 12
Rated current of main circuits, A	630; 1250; 1600; 2000; 2500; 3150
Rated busbar current, A	1250; 1600; 2000; 3150
Rated short-time withstand current (3 s), kA	20; 25; 31.5
Rated peak withstand current, kA	51
Environmental classification and location category	EN/IEC 60721-3-4 (outdoor); cold-climate version available
Thermal insulation in switchgear	- outdoor per EN/IEC 60721-3-4: without additional thermal insulation - cold-climate version: insulated enclosure
Closed service corridor	with service corridor
Type of medium-voltage line terminations	cable, overhead
Insulation level per IEC standards	IEC 62271-1 / IEC 62271-200 / IEC 60060-1 - standard insulation level
Withdrawable elements in cubicles	with drawout element
Overall dimensions, mm - width - depth - height	3000 750; 900; 1100 2700

Note on ratings. The values above reflect typical ranges for 6–10 kV MV switchgear. Achievable main-circuit and busbar currents depend on configuration (breaker type, busbar cross-section, type and quantity of connections) and are confirmed by the project documentation and O&M manual. For reference on the K-47 series: market offerings commonly cover main-circuit currents from 630 to 1600 A with interrupting capability 20/31.5 kA; higher current ratings are possible with appropriate apparatus.

Operating Conditions

K-47 is manufactured for outdoor installation in accordance with EN/IEC 60721-3-4 (location category for non-weatherprotected stationary use). This implies operation under elevated solar radiation, wind loads, sub-zero temperatures, and precipitation. The cold-climate version uses a reinforced insulated enclosure; both versions include space heaters with automatic control by temperature/humidity sensors to prevent condensation and to maintain proper conditions for secondary circuits.

Standard conditions: installation altitude up to 1000 m above sea level; ambient temperature up to +40 °C and down to -45 °C (outdoor), or down to -60 °C for the cold-climate version; pollution degree - Class II; wind speed - up to 34 m/s. For regions with intense insolation a sunshield over the control corridor is recommended. These limits and recommendations align with EN/IEC 60721-3-4 and common practice for 6–10 kV MV switchgear.

Product and environmental requirements are governed by IEC/EN 62271-200 (AC metal-enclosed switchgear and controlgear above 1 kV up to and including 52 kV) with references to environmental classes per EN/IEC 60721 and applicable restrictions for hazardous areas.

Layout and Design Solutions

The K-47 lineup is assembled from standardized cubicles (cells) mounted on a common steel frame. Each cubicle is partitioned into compartments: line terminations, busbars, drawout element, and relay/control cabinet. The control corridor is a closed walk-in space with a defined IP rating and fixed lighting; it accommodates protection and control IEDs, station-auxiliary equipment, and substation automation. This arrangement enables two-sided service access, safe maintenance, and independent pressure relief during internal-arc faults (pressure-relief flaps and vents on the roof/partitions).

The drawout trolley is the key assembly carrying the vacuum circuit breaker, fuses, voltage transformers (as per scheme), and isolating contacts of the main circuits. The trolley has three latched positions: “service/connected”, “test/disconnected” (primary circuits open, secondary circuits connected), and “maintenance/withdrawn”. The latching and shutter mechanisms prevent access to live parts when withdrawing; shutters close automatically when moving from the test to the maintenance position. A standard racking handle is used; additional trolley locking is provided for 31.5 kA ratings.

Busbars are air-insulated, bare, with fixed phase spacing. Transitions to overhead lines use roof bushing insulators and brackets; cable feeders use an enlarged termination compartment, convenient cable entries, and locations for CTs including earth-fault protection CTs. Relay cabinets house indication, control, and metering devices, as well as leading manufacturers’ microprocessor IEDs; secondary wiring is routed in metal conduits/cable ducts for EMC robustness.

Compatibility and expansion: K-47 supports busbar/bus-section couplers and extension of existing switchgear lineups of earlier/related series (K-37, K-49, K-59) using transition cubicles and coupling elements-useful for substation retrofits with mixed fleets.

The base frame is bonded to the grounding grid; all metallic parts of the cubicles and built-in equipment have reliable electrical contact with the structure. Local space heaters are provided in compartments, and corridor heaters switch on automatically at low temperature. To minimize consequences of internal-arc faults, pressure-relief and differential vents are used in compartments, and arc-flash protection with optical sensors blocks busbar reclose.

Safety and Interlocks

K-47 implements a full set of mechanical and electrical interlocks preventing incorrect operations, including: blocking trolley movement when the breaker is closed; blocking breaker closing in intermediate trolley position; blocking closing/withdrawal with the earthing switch engaged; interlocks for bus-section operations (breaker/disconnector); blocking energization of the SST on a grounded section; electromagnetic locks and limit switches on earthing switch drives. Containment is enhanced by shutters, compartmentalization, and louvered partitions that close automatically under gas pressure-meeting the intent of IEC/EN safety requirements for MV switchgear.

Variants and Options

Environment: outdoor per EN/IEC 60721-3-4; cold-climate insulated version available. Recommended: space heaters and condensation control; optional HVAC/anti-condensation package.
Terminations: cable/overhead, single-sided/double-sided; bus tie jumpers for section coupling.
Switchgear apparatus: vacuum circuit breakers (domestic/import lines, interrupting ratings up to 31.5 kA), VT/SST cabinets, combined cells with surge arresters and capacitors (engineered to order).
Control & protection: local/remote; ANSI/IEC functions (50/51, 50N/51N, 27/59, 81, 25, 79, etc.); SCADA/EMS integration via IEC 61850 / IEC 60870-5-104 (as engineered).
Metering & automation: revenue metering panels; AR/ATS; UFLS/UVLS; centralized alarm annunciation.
Enclosure: degree of protection not lower than IP34 (outdoor); higher for selected compartments. Doors with safety partitions, viewing windows, 220 V lighting and 36 V inspection lighting.

Typical Cubicle Configurations

Incoming feeder (cable/bus/overhead) with vacuum circuit breaker.
Outgoing feeder (cable/bus).
Bus-section circuit breaker; bus-section disconnector.
Voltage transformers (incl. with surge arresters).
SST cabinet: built-in up to 40 kVA (end cells of a lineup) or standalone 25–250 kVA.

Compliance with Standards

IEC/EN 62271-200 - AC metal-enclosed switchgear and controlgear above 1 kV up to and including 52 kV (product standard, incl. internal-arc classification).
IEC 62271-1 - Common specifications for switchgear and controlgear.
IEC 60060-1 - High-voltage test techniques - Part 1: General definitions and test requirements (dielectric tests).
IEC 60529 (EN 60529) - Degrees of protection provided by enclosures (IP Code).
EN/IEC 60721-3-4 - Environmental conditions - Classification of groups of environmental parameters and their severities - Stationary use at non-weatherprotected locations (outdoor).
IEEE C37.20.2 - Metal-clad switchgear (reference for North America, where applicable).

Engaging Contractors, Manufacturers, and Investors

We welcome cooperation with electrical installation and manufacturing companies interested in producing and supplying KRUN K-47. We will provide working documentation, specifications, bills of materials, as well as commissioning and deployment consulting. For investors we offer production business models (in-house assembly/contract manufacturing), tooling budgets, test-bay requirements, and training programs for engineering and maintenance staff.

Deliverables and Support

Within the project we prepare a complete document set: data sheets, single-line diagrams, primary and secondary schematics, specifications, manufacturing and QA procedures, passports and O&M manuals, plus a package of 3D models and drawings - AutoCAD (DWG/DXF), SolidWorks (SLDPRT/SLDASM), Parasolid (x_t/x_b), STEP/IGES - for rapid integration into the customer’s BIM/CAD. If required, we will adapt the layout to dimensional constraints, select breaker/CT/VT types to your standards, prepare spares kits, and provide supervisory installation and commissioning “turn-key”.

Why Work with Us

- Reduced lead time and risk: you receive a production-ready package that an average engineer can execute; we embed proven solutions for layout, interlocks, and arc-fault robustness.
- No pilot build needed: accumulated implementation experience lets you launch series immediately without a prolonged shakedown.
- Support at every step: we answer process questions, propose component substitutes, manage cooperation, and help pass conformity assessment to IEC/EN and OSHA/CE-related safety practices.