Standard solution: KSO cubicle retrofit — vacuum circuit breakers replacing outdated switchgear
Standard solution for retrofitting a 6 kV switchgear unit: 16 KSO-E cubicles, size 393, VV/VL and HGV vacuum circuit breakers, RS83 protection. PDF diagrams openly available, DWG set on request.
Published: 11.06.2026 · Author: engineering department of LLC "LK Energy"
A ready-made set of diagrams for a standard retrofit of a 6(10) kV switchgear unit built on KSO cubicles: 12 PDF files — a specification sheet for 16 KSO-E cubicles, size 393, single-line diagrams of the incoming, bus-tie and feeder cubicles, and the voltage-transformer and auxiliary-transformer cubicles with vacuum circuit breakers and RS83 microprocessor-based protection, a layout plan, an inter-cubicle cable schedule, the ShVOT DC control-power cabinet, and the ShchKM data-transmission unit. The drawings were produced by LK Energy engineers based on an actual 2025 network reconstruction project for external power supply (design stage R). PDFs are freely available below; the DWG set is available free of charge on request via the form.
What KSO retrofit is and when it beats replacing the cubicles outright
KSO retrofit is the modernization of an existing switchgear unit built on KSO cubicles, in which outdated switching apparatus is replaced with modern equipment. The key step is replacing the old switching device with a vacuum circuit breaker: in Soviet-era switchgear units this mainly means replacing oil circuit breakers (VMP, VMG); in cubicles fitted with load-break switches, it means installing a vacuum circuit breaker in place of the load-break switch. Along with the switching apparatus, the disconnectors, current transformers and relay protection are also upgraded (electromechanical relays give way to microprocessor-based terminals). The civil part of the switchgear unit — the building, cable ducts, incoming lines — is retained.
The key to this solution is the KSO-E cubicles in size 393: the new equipment is built to the dimensions of classic KSO-393 cubicles, so it fits into the existing switchgear rows in place of the old cubicles without rebuilding the premises. A two-section layout with a bus-tie circuit breaker and a bus-tie disconnector allows the switchgear modernization to be carried out section by section. Compared with fully replacing the switchgear with cubicles of a different size, retrofit does not require reconstructing the building or reworking the cable infrastructure — the designer determines the scope of construction and installation work based on the condition of the specific switchgear unit.
This standard solution gives the designer the full documentation package for the switchgear unit: primary diagrams for every cubicle type, secondary protection and signaling circuits, control power, telemetry, and inter-cubicle connections.
Technical parameters of the solution
- 6 kV switchgear unit (KRPB-6 kV): 16 cubicles in two sections (7 + 9), bus bridge, cubicle pitch 800 mm, row length 8200 mm
- KSO-E cubicles, size 393: KSO-E-17V/6/630-393V (feeders, incomers), KSO-E-23 (auxiliary-transformer cubicle), KSO-E-11A (voltage-transformer cubicle), KSO-E-14V/14 (bus-tie circuit breaker/disconnector)
- Switchgear parameters: 6 kV, busbars rated 630 A (AD31 6x60), rated breaking current 20 kA
- Vacuum circuit breakers: VV/VL-12-25/1000-U2 (pole spacing 150 mm) — feeder cubicles; HGV 2141 (12 kV, 630 A, 25 kA) — incomers
- Disconnectors RR/EL-10-630-25U2 (bus and feeder), surge arresters — OPNp-6/7.2
- Protection: RS83-AV2 terminals (incomers, feeders), RS83-V1 + Altra 32-z-16 (voltage protection, voltage-transformer cubicle)
- Metering: TOLU-10 current transformers (accuracy class 0.5S/10P), TZLM-1/TZLU-125 (earth-fault protection), NAMI-UE-6 voltage transformer (accuracy class 0.2/0.5)
- Auxiliary-transformer cubicle: TMG-16 transformer (16 kVA, 6/0.4 kV), PT 011 fuses; commercial metering: SL7000 meters (accuracy class 0.5S) and NIK 2303
- Control power: ShVOT cabinet built on BPN-1002/BPT-1002 units (rectified, 220 V), EL-17 insulation monitoring
- Telemetry: ShchKM cabinet with a TS-485 data-transmission module, RS-485 interface
- Year of development: 2025 (design stage R, actual reconstruction project), diagram language — Ukrainian; some purchased-equipment designations in the bill of materials — in Russian
- Ratings for a specific implementation are agreed via the specification sheet
Package contents and downloads
| No. | Document | Contents | File |
|---|---|---|---|
| 1 | KSO-E cubicle specification sheet (2 sections, 16 cubicles) | Primary-connection diagrams, equipment table for each cubicle | |
| 2 | "Incomer No. 1" cubicle — single-line diagram | HGV 2141 vacuum circuit breaker, RS83-AV2 protection circuits, metering | |
| 3 | "Bus-tie circuit breaker" cubicle — diagram | RS83 protection circuits, signaling and interlocking | |
| 4 | "Bus-tie disconnector" cubicle — diagram | Bus-tie disconnector signaling circuits | |
| 5 | "Feeder" cubicle with VV/VL-12 — diagram | Feeder cubicle with VV/VL-12-25/1000 vacuum circuit breaker | |
| 6 | "Feeder" cubicle with HGV 2141 — diagram | Feeder cubicle with HGV 2141 vacuum circuit breaker | |
| 7 | "VT-1" cubicle — diagram | NAMI-UE-6 voltage transformer, RS83-V1 protection | |
| 8 | "Auxiliary transformer-1" cubicle — diagram | TMG-16 auxiliary-supply transformer, PT 011 fuses | |
| 9 | Cubicle layout plan | Two rows of cubicles, bus bridge, ShVOT, switchgear-unit dimensions | |
| 10 | Inter-cubicle cable schedule | Harnesses/cables of secondary circuits between cubicles | |
| 11 | ShchKM cabinet — external view and diagram | Data-transmission unit: TS-485 module, RS-485 splitter | |
| 12 | ShVOT control-power cabinet — diagram | BPN-1002/BPT-1002 power supply and charging units, insulation monitoring |
Preview
DWG set on request
We will send the complete DWG set of switchgear-unit diagrams to your email free of charge: all cubicle types (incomer, bus-tie circuit breaker, bus-tie disconnector, feeders, voltage-transformer, auxiliary-transformer), specification sheet, layout plan, cable schedule, and the ShVOT and ShchKM cabinets.
Frequently asked questions
Can this solution be used in a modernization project for my own switchgear unit?
Yes — as a standard basis for retrofitting a switchgear unit built on KSO cubicles. Site-specific adaptation, relay protection and automation setpoint calculations, the cable schedule, and compliance with the current PUE (electrical installation rules)/DSTU (Ukrainian national standards) are the designer's responsibility. The solution corresponds to an actual 2025 reconstruction project (design stage R).
What equipment is specified?
KSO-E cubicles, size 393, manufactured by LK Energy, VV/VL-12 and HGV 2141 vacuum circuit breakers, RR/EL disconnectors, RS83-AV2 and RS83-V1 protection terminals, TOLU-10 current transformers, NAMI-UE-6 voltage transformer, SL7000/NIK 2303 metering.
How can I get the DWG files?
Fill out the form on this page — we will send the set to your email within one business day.
Does LK Energy manufacture this equipment?
Yes. We manufacture KSO-E cubicles and ShVOT and ShchKM cabinets at our own production facility in Odesa; we also carry out complete equipment deliveries for switchgear-unit modernization.
Will you help select the right configuration for my switchgear unit?
Yes, we advise designers: choosing cubicle types, vacuum circuit breakers and protection devices, filling out the specification sheet — +38 067 104 94 91. See also: standard solution for a 10 kV switchgear unit on KSO cubicles, 10 kV switchgear unit on KSO with VV/TEL.
The diagrams are provided as a reference standard solution. Site-specific adaptation, relay protection and automation setpoint calculations, and compliance with current standards (PUE, DSTU, DBN (state building codes)) are the designer's responsibility. LK Energy is not liable for application of the solution without adaptation to the conditions of a specific site.
Any questions left?
Write or call us — we answer to the point. Preliminary reply within 24 hours.
+380 67 104 94 91