Standard Solution: 6(10) kV Switchgear (RP) on KRU-E Switchgear Panels (KM-1F Envelope) with MRZS Terminals

Published: 11.06.2026 · Author: Engineering Department, LK Energy Group

A ready-made set of Stage P protection and automation (RZA) schematics for a 6(10) kV switchgear (RP) built on KRU-E withdrawable-element switchgear panels in the KM-1F envelope with MRZS microprocessor-based protection terminals: 158 sheets in the consolidated set — two incomers, a bus-tie circuit breaker with automatic transfer switching (ATS), a bus-tie disconnector with central signaling (CS), two voltage transformers, two auxiliary-supply transformers (TVP) with an auxiliary-supply ATS (ATS-SN) circuit, outgoing feeders (including one with a commercial metering unit), and inter-panel connections. The set also includes a technical questionnaire. The schematics were developed by LK Energy Group engineers based on an actual reconstruction project for an operating facility (2025). The PDF is freely available below; the DWG is available after a short registration.

What sets the KM-1F design with MRZS apart

This solution is the fourth hardware platform in our RP lineup. For an explanation of what a 6(10) kV switchgear (RP) is and when a double-bus-section design is used, see the page on the baseline solution on KSO cubicles. Here we address the same task on a fundamentally different equipment base:

Withdrawable elements instead of fixed cubicles

KRU-E-6/630 cabinets (KM-1F envelope) with KM-1 withdrawable elements: BB/VL-12-25/2000-U2 vacuum circuit breakers on the incomers and bus-tie breaker, BB/VL-12-25/1000-U2 on the feeders, a withdrawable 630 A voltage transformer, a 630 A TShST busbar element in the TVP cubicles, and a 2000 A ShR busbar element in the bus-tie disconnector cubicle. Front-access maintenance, IP41 protection rating with the doors closed.

MRZS terminals instead of RS83

MRZS-F2J12 — incomers and outgoing feeders, MRZS-S2J12 — bus-tie circuit breaker, MRZS-U2D12 — voltage transformer cubicles, MRZS-05L — central signaling.

CS — central signaling

The bus-tie disconnector cubicle implements the RP central signaling circuit on an MRZS-05L(CS) terminal: alarm signaling buses, "dark bus" monitoring, and a "CS fault" signal.

ATS at two levels

ATS on the bus-tie circuit breaker with voltage interlocks from both sections' voltage transformers, plus auxiliary-supply ATS (ATS-SN) on the TVP side.

Commercial metering unit

A dedicated outgoing-feeder design with metering circuits (class 0.5S current transformers, a meter mounting position) and a commercial metering reserve on the incomers.

1600 A busbars

(AD31 10×100), 16 cubicles across two bus sections, 25 kA thermal withstand rating.

Technical parameters of the solution

• Rated voltage: 6 kV (6(10) kV class, highest operating voltage 7.2 kV); two bus sections, 16 cubicles
• Busbars: 1600 A (AD31 10×100); main circuits 630 A
• Thermal withstand 25 kA (3 s), dynamic withstand 51 kA
• Cabinets: KRU-E-6/630-03/-22/-105/-201/-601-U3 in the KM-1F envelope, with withdrawable elements, front-access maintenance, IP41
• Switching: BB/VL-12-25/2000-U2 (210 mm) and BB/VL-12-25/1000-U2 (150 mm) vacuum circuit breakers on KM-1 withdrawable elements
• Protection: MRZS microprocessor-based terminals — MRZS-F2J12, MRZS-S2J12, MRZS-U2D12, MRZS-05L (CS)
• Measurement: TCS2-12-11.05.3 current transformers (200/5, 400/5, 600/5; class 0.5/10P, 0.5S/0.5/10P on the incomers), TZLU-205-1 30/1 zero-sequence current transformers on the feeders
• Voltage transformer: 3×IVS1F-1.1.1, 6000:√3/100:√3/100:√3/100:3, class 0.5/3P/6P, 630 A withdrawable element
• Auxiliary supply: TSKL-16 auxiliary transformer (TVP) (16 kVA, 6/0.4 kV D/Yn-11) with PT 011-6-3.2-40 U3 fuses + ATS-SN
• Surge protection: OPNp-6/6.6/10/550/IV/UKhL1 surge arresters
• Auxiliary circuits: control and signaling 220 V; voltage-transformer circuits 100 V; compartment lighting 12 V
• Climatic design category U3
• Year developed: 2025, Stage P, schematic language Ukrainian, format DWG (AutoCAD)
• Ratings for a specific implementation are agreed via the technical questionnaire

Package contents and downloads

The cubicle sections with circuit breakers contain schematic diagrams of the current protection circuits, voltage circuits, control and signaling circuits, compartment lighting circuits, and an explanatory single-line diagram.

• Full set of schematics in one PDF (158 sheets)

Schematic previews

DWG package after registration

You get the full DWG package (a consolidated file of schematics for all 16 cubicles: incomers, bus-tie circuit breaker, bus-tie disconnector with CS, voltage transformers, TVP with ATS-SN, outgoing feeders, inter-panel connections, plus the technical questionnaire) free of charge after registration. Registration takes your name, phone and e-mail.

Frequently asked questions

The schematics are provided as a reference standard solution. Site-specific adaptation, RZA setpoint calculation, and compliance with applicable codes (PUE, DSTU, DBN — Ukrainian building codes) are the responsibility of the design engineer. LK Energy Group is not liable for use of the solution without adaptation to the conditions of a specific facility.