KRU “Omega” Medium-Voltage Switchgear 6(10) kV

The “Omega” series of 6/10 kV medium-voltage switchgear is designed for receiving, distributing, and switching three-phase AC at 50/60 Hz in systems with an isolated neutral or a neutral earthed via an arc-suppression reactor / resistor. The solution targets indoor distribution switchgear of substations and industrial facilities where safety, modularity, and ease of maintenance are required.

The enclosure is a modular steel construction made of galvanized sheet with powder-coated front parts (high corrosion resistance). A distinctive layout feature is the busbar system in the upper rear section, a withdrawable unit in the middle, and the cable/bus compartments beneath it or beneath the busbar compartment. This architecture increases usable feeder volume and ensures full front access, enabling one-sided operation and maintenance when required.

For arc-fault safety the design uses metal-clad compartmentalization with solid metallic and insulating barriers. Typical compartments include: a relay/low-voltage compartment, a withdrawable circuit-breaker compartment, a busbar compartment, and a cable compartment. On request, the truck can be motorized for remote test ↔ in-service movement, and the earthing switch can be equipped with an electric actuator (ON/OFF). Optional features include video surveillance (breaker / earthing-switch compartments) with display at the control desk, contact-temperature monitoring, and a front mimic panel.

Scope of application

“Omega” switchgear is used at generation, transmission, and distribution facilities as well as by industrial consumers:

Indoor MV switchgear of package substations (KTP) and urban 6-10 kV distribution points;
Industrial plant substations; auxiliary switchgear of power plants (TPP/HPP/CCPP);
Utilities and infrastructure: water utilities, pump stations, heat centers, data centers;
Factory-built modular substations and retrofit of existing switchgear line-ups;
Back-to-back (double-row) line-ups - interconnection by bus bridges or cables (on request).

Service conditions

Environmental conditions - EN/IEC 60721-3-3 (indoor); operating ambient -25…+40 °C;
Altitude - up to 1000 m a.s.l. (above this - insulation/thermal verification by calculation);
Non-hazardous atmosphere, free of conductive dust and aggressive vapors/gases;
Degree of protection - IP31 (IEC 60529);
Maintenance access - one-sided or two-sided, depending on the switchgear layout.

Design features

Full compartmentalization: LV/relay compartment ⋅ withdrawable unit ⋅ busbar ⋅ cable compartment;
Withdrawable vacuum circuit-breaker with optional motorized racking (test/in-service);
Motor drive for the earthing switch (ON/OFF), interlocks per safety logic;
Options: cameras in breaker/earthing-switch compartments, contact-temperature monitoring, front mimic panel;
Bus bridges / cable interconnections for double-row line-ups; common earthing bar per IEC 61936-1;
Multi-point door latching, keyed locks; directed pressure-relief upwards.

Standards compliance

IEC 62271-200 - metal-enclosed / metal-clad MV switchgear, LSC/PM; internal-arc classification IAC (as specified);
IEC 62271-100 - 12 kV vacuum circuit-breakers; IEC 62271-102 - earthing switches;
IEC 60071-1:2019 - insulation coordination (standard insulation level);
EN/IEC 60721-3-3 - environmental conditions (indoor); IEC 60529 - IP degrees of protection;
IEC 61000-6-2 / 61000-6-4 - EMC (industrial immunity/emissions).

Reliability and lifetime

Internal-arc effects confined to a single compartment, minimizing impact on adjacent panels;
Mechanical and electrical interlocks - prevention of incorrect operations;
Metal cable ducts for secondary circuits - EMC robustness and serviceability;
Powder-coated galvanized steel - high corrosion resistance and durability.

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	one-sided; two-sided
Insulation level (IEC 60071-1:2019)	standard
Environmental conditions	EN/IEC 60721-3-3 (indoor)
Degree of protection	IP31 (IEC 60529)
Overall dimensions, mm - width - depth - height	650; 800; 1000 1500; 1900 2360