K-63 Medium-Voltage Switchgear 6(10) kV

The K-63 series is a family of 6(10) kV medium-voltage switchgear for receiving, distributing, and switching three-phase power at 50/60 Hz in systems with an isolated neutral or a neutral earthed via an arc-suppression reactor / resistor. The metal-clad concept with a withdrawable circuit-breaker, rigid compartmentalization, and comprehensive interlocking enables safe operation and confines fault effects within a single compartment.

KRU K-63 is designed for all types of power plants, utility and plant substations, oil & gas facilities, and urban/rural distribution networks. Panels can be supplied to extend existing switchgear line-ups and connect via transition panels or directly. Installation in factory-built modular buildings (incl. series K-59) and brownfield retrofit of existing switchgear are supported with minimal civil works.

The cabinet body is welded from sheet steel with RAL 7032 powder coating. Each panel comprises a base enclosure, a withdrawable unit (truck), and a relay/control compartment. The primary section may include current/voltage transformers, primary conductors, and separable contacts (providing the disconnector function on the withdrawable unit). The relay compartment houses P&C IEDs, control, metering, annunciation, and terminal blocks for convenient commissioning and service.

A key layout feature of K-63 is the busbars arranged at the bottom with the feeder (line) compartment above. This simplifies work with instrument transformers, earthing switches, and power cables, and provides easy access for busbar terminations. Rear covers of the line and busbar compartments are removable and fitted with viewing windows; through-access to section busbars is available when required. Secondary wiring in MV compartments is protected by covers; cables in the truck compartment are routed along the sidewalls.

The front door of the truck compartment has a viewing window and can remain closed in all truck positions (in-service / test / intermediate). The door carries voltage-presence indicators (feeder / busbar), a mimic showing truck position, and breaker/earthing-switch status to help prevent human error. Shifting the truck to the maintenance position is performed after racking to test; two-sided maintenance access is available.

Standards compliance.

IEC 62271-200 - requirements for metal-enclosed MV switchgear; internal-arc classification IAC (as specified);
IEC 62271-100 - 12 kV vacuum circuit-breakers; IEC 62271-102 - earthing switches;
IEC 60071-1 - insulation coordination (standard insulation level);
EN/IEC 60721-3-3 - environmental conditions for indoor installations; IEC 60529 - degree of protection IP31.

Scope of application

K-63 panels are intended for indoor MV switchgear rooms and modular substations in new-build and retrofit projects:

utility transmission and distribution substations at 6–10 kV;
auxiliary switchgear of TPP/HPP/CCPP units; busbar sectioning;
industrial substations (metallurgy, chemicals, pulp & paper, agro-industry);
oil & gas infrastructure: CPF/booster stations, well pads, compressor/GPP sites;
electrification of utilities, agricultural, logistics, and IT facilities.

Service conditions

Climate - EN/IEC 60721-3-3 (indoor, weather-protected); ambient -25...+40 °C (below this range - panel heating required);
Altitude up to 1000 m a.s.l. (higher - insulation/thermal derating by calculation);
Non-hazardous atmosphere, free of conductive dust;
Enclosure degree of protection - IP31; maintenance access - two-sided.

Design features of K-63

Bottom busbar arrangement with the line compartment above - convenient for cabling and service;
Withdrawable unit with separable contacts; inspection windows and front-panel mimic;
Removable rear covers with viewing windows; through-access to section busbars;
Protected routing of secondary wiring; cables along the sidewalls of the truck compartment;
Mechanical/electrical/key interlocks prevent incorrect operations;
Compatibility with modular buildings (incl. K-59); transition options for coupling to existing switchgear.

Configuration and options

Vacuum circuit-breaker 12 kV (manufacturer - as specified), CTs/VTs, earthing switch;
Functions: incoming, bus-section, outgoing feeders, metering/measurement, VT panel, ATS/AR;
Voltage-presence indicators (feeder/busbars), arc-flash protection (on request);
P&C IEDs supporting AR/ATS/UFLS, SCADA integration; IEC 61850 if required;
Options: enhanced IP, relay-compartment heating, heavy-duty anchors, transition panels for coupling.

Reliability and lifetime

Internal-arc effects confined within a single compartment; adjacent panels remain serviceable;
M2/E2/C2-class vacuum circuit-breakers - endurance up to 30,000 CO operations;
RAL 7032 powder coating; protected secondary routing - durability and EMC robustness;
Unified interlocking logic and clear position indication reduce operator error risk.

Technical data

Rated voltage, kV	6; 10
Maximum system voltage, kV	7.2; 12
Rated current of main circuits, A	630; 1250; 1600; 2000; 2500; 3150
Rated busbar current, A	1250; 1600; 2500; 3150
Thermal withstand current (3 s), kA	20; 25; 31.5
Dynamic withstand current (1 s), kA	51; 64; 81
Maintenance access	two-sided
Insulation level (IEC 60071-1:2019)	standard
Environmental conditions	EN/IEC 60721-3-3 (indoor)
Degree of protection (IP)	IP31 (IEC 60529)
Overall dimensions, mm - width - depth - height	750; 1125 1400 2300

We offer documentation for manufacturing KRU K-63:

Single-line diagrams, data sheets, technical description, and feasibility inputs.

Manufacturing drawings and 3-D models. Layout/assembly drawings, BOMs, secondary schematics, cable schedules.

Contract manufacturing of subassemblies. We organize enclosure/mechanism production with partners; you perform assembly, wiring, and routine factory tests.

Adaptation and integration. Drop-in panels for interfacing with existing busbars and P&C, expansion of installed switchgear.