Standard solution: relay protection circuit set for a КСО cubicle (РС83-АВ2 / МРЗС)

Published: 18.07.2026 · Author: engineering department, LK Energia LLC

A ready set of relay protection and automation circuits for a КСО-10 kV switchgear cubicle — the secondary fit-out of the cubicle built on РС83-АВ2 / РС83-АВ3 or МРЗС microprocessor relays with breaker failure (УРОВ), busbar logic protection (ЛЗШ) and underfrequency load shedding (АЧР) functions and 220 V operative supply (per project). The solution is compiled from real 10 kV distribution point projects of 2023–2024 and complements the basic КСО cubicle set. The DWG set is free on request via the form.

What the КСО cubicle protection set includes

This is the schematic part that brings the КСО cubicle to life: the current transformer circuits, the vacuum circuit breaker control circuits, the protection relay and all the secondary wiring. The set of protections depends on the role of the cubicle (incomer, bus section, feeder) and typically includes overcurrent protection, breaker failure protection (УРОВ), busbar logic protection (ЛЗШ), underfrequency load shedding (АЧР) and an output to the central alarm system. The set matches the dimensional and power design of the cubicle — see the standard 10 kV distribution point solution on КСО cubicles.

Technical parameters

• Protection relays: РС83-АВ2 / РС83-АВ3 or МРЗС (per project)
• Protection and automation functions: overcurrent protection, breaker failure (УРОВ), busbar logic protection (ЛЗШ), underfrequency load shedding (АЧР)
• 220 V operative supply (per project)
• Current circuits via test blocks; vacuum circuit breaker control (breaker type per project)
• Versions for incomer, bus section (СВ) and outgoing feeder cubicles
• 10 kV bus section ATS, output to the central alarm system (ЦС), event recording circuits
• Drawing language — Ukrainian; based on real projects of 2023–2024
• Protection settings for a specific site are not included — they are defined by the site-specific design

DWG set on request

We will send the full set of cubicle protection circuits (schematic circuit diagram, control and alarm circuits, terminal rows, equipment list) in DWG format free of charge by email. Individual sheets can be sent as PDF previews on request.

We manufacture the equipment at our own facility in Odesa; see also the equipment catalog.

FAQ

How does РС83-АВ2 differ from МРЗС?

These are different series of microprocessor protection relays for 6–10 kV feeders. The cubicle protection circuit design is similar for both; the specific relay is chosen by the design engineer based on the required functions and customer preference. Both options are provided in the set.

What are УРОВ and ЛЗШ?

УРОВ is breaker failure protection: if the feeder breaker fails to trip, the trip command is passed to the upstream level. ЛЗШ is busbar logic protection, which speeds up clearing of short circuits on the busbars. Both functions are included in the schematics.

Is this a complete КСО cubicle?

No — this is specifically the set of protection circuits (the secondary fit-out). It complements the power and dimensional design of the КСО cubicle. See the КСО standard solutions section for complete cubicles and distribution points.

The full DWG set is free on request via the form below. We usually send it by email within one business day and advise design engineers on the equipment configuration: +38 067 104 94 91.

The drawings are provided as a reference standard solution. Site-specific adaptation, load and setting calculations, and compliance with the applicable codes (ПУЕ, ДСТУ, ДБН) are the responsibility of the design engineer. LK Energia accepts no liability for use of the solution without adaptation to the conditions of a specific site.