KVP-10/13 — switchgear retrofit: engineering, manufacturing, implementation

The KVP-10/13 cell retrofit is a technically justified replacement of the drawout unit with an oil circuit breaker by a modern module with a vacuum (or SF₆) circuit breaker, while retaining the KRU2-10 cubicle, busbar systems, and cable terminations. We adapt the truck and interfaces to preserve the mating geometry, provide standard interlocks, and prevent operator error. The result is increased switching life, reduced operational risk, and minimized installation downtime.

What changes: the truck (drawout unit) assembly, circuit breaker, shutter assembly, mechanical and electrical interlocks, set of guides and stops, secondary cassette/connector; if required — earthing-switch drive, front door, and instrument transformers.
What remains: the cell enclosure, cabinet layout, incoming/outgoing cables, bus ducts and foundation, and the switchgear scheme.

Three implementation scenarios:
— Re-Use: install a new breaker on the existing DU using adapter frames and bring interlocks up to standard — minimal CAPEX, but a higher share of site supervision and adjustments.
— Drop-in: a new drawout unit “to KVP-10/13 form-fit” that mirrors connection dimensions and interlock logic — a plug-in replacement with a short outage.
— Factory Retrofit Module: a factory-built module with shutters and interlocks implemented, type tests performed, and unified interfaces — maximum predictability of schedule and risk.

Input data for engineering

Before project start we request: the single-line diagram, short-circuit parameters, feeder list, photos/dimensions of the cell (front, sides, contact window), installation altitude, climatic execution and required IP rating, desired Protection & Control/telecontrol functions, as well as details of existing breakers (VMP-10/VMPP-10/analogues) and secondary connector types. This allows us to agree in advance the tolerances for phase-to-phase clearances, racking depth, stop positions, and the location of the secondary cassette.

Technical characteristics (typical for KVP-10/13 retrofit)

Parameter	Typical value / range	Comment
Voltage class, kV	10 (adaptation to 6 possible)	Per network and site insulation clearances
Frequency, Hz	50 / 60	Coordination with P&C and ATS
Rated current, A	630–1250 (opt. 1600)	Selection by thermal and dynamic calculation
Breaking capacity, kA	20–31.5	With margin relative to legacy “13” series
Mechanical endurance	≥ 10,000 operations	For VCBs with spring/magnetic drives
DU positions	Service / Test / Disconnected	Latched on guides and locks
Circuit breaker operating mechanism	Spring-charged or electromagnetic	To match switching duty and P&C requirements
Front protection	IP per project (typically IP20…IP54)	Increased with covers and gaskets
Secondary interface	Removable cassette/connector, unified pinout	Marking and test reports included in pre-commissioning
Dimensional compatibility	“KVP-10/13 form-fit”	Adapter frames and interfaces included
Protection relays	Microprocessor-based IEDs	Event recording and oscillography
Testing	Routine and acceptance	Factory (FAT) and/or on-site (SAT)

Compatibility and geometry

The new truck reproduces KVP-10/13 connection dimensions: pole projection, primary contact centerlines, stop positions, and shutter-window location. During the site survey we capture the as-found geometry and compensate deviations with adjustable guides, spacers, and adapters. Mandatory checks include receptacle/plug contact concentricity, closing forces, and correct shutter operation in “test” and “disconnected” positions.

Safety and operation

Mechanical and electrical interlocks prevent DU movement with the breaker closed, block withdrawal without earth applied, and ensure shutter closure over primary contacts in non-service positions. If required, we implement motorized racking with door-closed control, position indicators, and condition sensors integrated into SCADA/DCS.

Scope of the retrofit kit

Truck with breaker; set of primary-contact adapters; shutter mechanism; interlocking system; secondary cassette; set of flexible/rigid bus links; fastening hardware and setting templates; operating and installation documentation; pre-commissioning test package with forms. Per project — P&C door, CTs/VTs, intermediate cabling, space-heating/ventilation kit.

Design options and comparison

Criterion	Re-Use (adaptation)	Drop-in (new DU)	Factory Retrofit Module
Implementation timeline	Medium; depends on modifications	Short	Minimal
CAPEX	Low	Medium	High
On-site work share	Elevated	Low	Minimal
Factory completeness	Partial	High	Maximum
Sensitivity to cell geometry	High	Medium	Low/medium
Flexibility in breaker choice	High	High	High (within the module family)

Standards and tests

The project complies with current MV equipment standards: general requirements for circuit breakers and metal-clad switchgear, enclosure IP ratings, requirements for disconnectors/earthing switches, and type/routine tests. The pre-commissioning plan includes geometry checks, electrical characteristics, interlock performance, contact-resistance measurements, as well as routine and acceptance tests (FAT/SAT).

Documentation and manufacturing

We provide questionnaires, preliminary technical documentation (for tenders), a complete set of fabrication drawings (DWG/DXF), 3D models (STEP/Parasolid), assemblies (SolidWorks), BOMs and ITP/QA plans, schematic and wiring diagrams, routing sheets, assembly/adjustment instructions, pre-commissioning procedures, typical retrofit design packages, O&M manuals, and maintenance procedures. Drawings are tailored to the customer’s equipment and the capabilities of the specific manufacturing site.

Project economics

By retaining the enclosures and cable infrastructure, the retrofit costs less than full switchgear replacement and takes significantly less time to commission. A vacuum breaker reduces maintenance costs and eliminates oil handling. Staggered modernization across several cells minimizes total downtime.

FAQ — KVP-10/13 retrofit

How long does it take to replace one drawout unit?

With the Drop-in option — from a few hours to 1–2 shifts, including interlock adjustments and pre-commissioning (PCI). With Re-Use — 1–3 shifts, depending on the scope of modifications and geometry checks.
Do we need to replace the entire switchgear, or is a DU retrofit enough?

In most cases the drawout-unit retrofit is sufficient: the enclosure, bus systems, and cable circuits remain. Full replacement is required only when the enclosure is critically worn.
Which vacuum breakers are compatible?

Vacuum or SF₆ circuit breakers rated 6–10 kV, 630–1600 A, with 20–31.5 kA breaking capacity. Selection is based on cell geometry, drive type, and P&C requirements.
What testing is performed after installation?

Pre-commissioning includes geometry/closing-force checks, interlock verification, insulation and resistance tests, functional checks of P&C/ATS, and FAT/SAT reports.
What documentation is provided for manufacturing and O&M?

Fabrication drawings (DWG/DXF), 3D models (STEP/Parasolid), specifications, diagrams, job cards, instructions, PCI, O&M manuals, and maintenance schedules adapted to your workshop.
Will the entire switchgear have to be taken out of service?

No. Upgrades are performed cell-by-cell, minimizing downtime for consumers.
What input data are required for the retrofit study?

Single-line diagram, short-circuit data, feeder list, photos/dimensions of the cell, altitude/climate/IP data, and details of existing breakers and secondary connector types.