0.4 kV VRU/VRP: typical solution, PDF/DWG

Published: 11.06.2026 · Author: engineering department of LK Energy Group

Working drawings of the typical solution for 0.4 kV main incoming distribution boards (VRU/VRP) for buildings and industrial facilities: three cabinets from a real 2024 order — a 400 A VRP with a metering unit and a "1-0-2" switch (direct supply or via a voltage stabilizer — bypass), a 400 A distribution VRP for 17 lines, and a 1600 A VRP on three panels. Each set includes a single-line diagram, a secondary-circuit connection diagram, a general view of the cabinet and a bill of materials (20 sheets in total). The PDF is freely available below; the DWG package is provided free of charge after a short registration.

What is a VRU, and how does it differ from a GRShch (main switchboard)

VRU is a main incoming distribution device: a set of switching and protective apparatus and metering instruments installed at the incoming point of a 0.4 kV supply line into a building. The VRU receives power from a transformer substation (KTP) or the supply network, allows the entire electrical installation to be disconnected, provides metering, protection against overloads and short circuits, and distributes power among distribution and group panels. VRP is a main incoming distribution device; VRP more often denotes a specific cabinet or panel from which a VRU is assembled.

GRShch is the main distribution switchboard. The functions are the same — receive electricity, perform metering and distribute it — but the term GRShch is usually used for the incoming board of large buildings and industrial facilities: multiple incomers, busbar sectionalizing, automatic transfer switch (ATS/AVR), and supply to critical consumers. In practice the terms are often used as synonyms; the exact composition is determined by the project: for residential buildings and smaller facilities, VRU/VRP is more commonly used, while GRShch is used for facilities with a more developed power supply scheme.

This typical solution presents a lineup of VRP cabinets for a single facility in three typical configurations: an incoming cabinet with metering and backup, a distribution cabinet for process equipment, and a high-capacity 1600 A incoming cabinet that collects inverter feeders and power panels.

Technical parameters of the solution

Common to the set:

Network: 400 V AC, 50 Hz; IP31 enclosure — ShK frame cabinets (2200×900×600, 2000×600×600) with a 100 mm plinth, manufactured by LK Energy Group; cable entries from above
Surge protection: T1+T2 300 V surge arrester (3+0) behind a 100 A fuse disconnector with 22×58 gG fuses
Voltage monitoring: 0–400 V voltmeter with a CS 16 66 U phase selector switch, phase-presence indicator lamps on the doors
Switching and protective apparatus — load-break switches, moulded-case and modular circuit breakers (the manufacturer is chosen by the customer); metering via a NIK 2301 AP3 transformer-connected meter
Design stage: detailed design (RD); year of development: 2024; drawing language: Ukrainian

Design 1 — 400 A VRP with metering and backup input: 400 A load-break switch incomer + 400 A (36 kA) circuit breaker; 400 A "1-0-2" changeover switch: direct supply or via a stabilizer (bypass); two AD31 30×10 busbar sections; outgoing lines — 250 A and 100 A (63 and 80 A) circuit breakers, 3p C16/C32 modular breakers; technical metering on section 2 — NIK 2301 + 400/5 accuracy class 0.5 current transformers + test terminal block. In this solution the backup is switched on manually via the switch; for automatic transfer of the backup supply, see the typical solution for 0.4 kV automatic transfer switches (ATS/AVR).

Design 2 — 400 A distribution VRP: 400 A load-break switch incomer; a single 400 A busbar section; two mounting panels in a 2200×900×600 ShK cabinet; 17 outgoing lines — 3p C20/C32 (10 kA) modular breakers and 100 A circuit breakers set at 63 A (process equipment and lighting panels); metering via NIK 2301 + 150/5 current transformers.

Design 3 — 1600 A VRP on three panels: 1600 A load-break switch incomer; 1600 A busbars (input via AVBbShv 4×(4×240) cables); 7 feeders on 250 A circuit breakers (inverter lines) + 4 feeders on 400 A circuit breakers set at 320 A (compressor room panel, heat pump panel, backup).

The ratings of a specific design (incomer current, number and settings of outgoing lines, metering unit) are agreed based on the technical questionnaire.

Package contents and downloads

No.	Document	Contents	File
1	400 A VRP cabinet with metering and backup input	Single-line diagram, secondary circuits, general view, bill of materials (6 sheets)	PDF
2	400 A distribution VRP cabinet for 17 lines	Single-line diagram for 2 panels, secondary circuits, general view, bill of materials (7 sheets)	PDF
3	1600 A VRP cabinet on three panels	Single-line diagram, secondary circuits, general views of the panels, bill of materials (7 sheets)	PDF

Preview

Single-line diagram of a 400 A VRP cabinet with a NIK 2301 metering unit and an input switch to a stabilizer

Single-line diagram of a 400 A distribution VRP cabinet for 17 outgoing lines

Single-line diagram of a 1600 A VRP cabinet on three panels: 1600 A incomer, 250–400 A feeders

DWG package after registration

The full DWG assembly of the order — 10 cabinets in a single AutoCAD file (VRP-1…VRP-6, VRP-9 and the facility's distribution panels): single-line diagrams, secondary circuits, general views, bills of materials. You get it free of charge after registration. Registration takes your name, phone and e-mail.

Frequently asked questions

Can these diagrams be used in the design of my own building?

Yes — as a typical base solution for the electrical (EM/EP) section. Site adaptation, load calculation and compliance with the current PUE (electrical installation rules) / DSTU (Ukrainian national standards) is the responsibility of the design engineer. The drawings were produced for a real 2024 production order by LK Energy Group (detailed design stage).

How does a VRU differ from a GRShch?

The functions are the same — receive 0.4 kV electricity, perform metering and distribute it. VRU/VRP is the typical name for a building's incoming device; GRShch usually refers to the incoming board of large facilities with multiple incomers, busbar sectionalizing and an automatic transfer switch (ATS/AVR). In practice the terms are often used as synonyms; the exact composition is determined by the project.

What equipment is used in the diagrams?

400/1600 A load-break switches, moulded-case and modular circuit breakers, T1+T2 surge arresters, fuse disconnectors; metering via NIK 2301 with current transformers. The equipment manufacturer is chosen by the customer — the design is agreed based on the technical questionnaire.

How do I get the DWG files?

Click "Get DWG" in the "Solution files" block at the top of the page and complete a short registration (name, phone and e-mail). How you will receive the set is shown in the same block.

Does LK Energy Group manufacture VRU/VRP cabinets?

Yes. We manufacture VRP cabinets, ShK frame enclosures, and 0.4 kV switchgear equipment at our own production facility in Odesa. We advise design engineers on configuration and on filling out technical questionnaires: +38 067 104 94 91. See also: typical solution for a 10/0.4 kV transformer substation (KTP) with a low-voltage switchgear (RUNN), ShchO-90 panel for a package transformer substation (ZTP), 0.4 kV automatic transfer switch (ATS/AVR).

The diagrams are provided as a reference typical solution. Site adaptation, verification of protective-device selectivity and compliance with applicable standards (PUE, DSTU, DBN — Ukrainian building codes) is the responsibility of the design engineer. LK Energy Group is not liable for the application of this solution without adaptation to the conditions of a specific facility.

Typical Solution: VRU/VRP — Incoming Distribution Devices for Buildings

Solution files