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)

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

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.

PDF — Download KVP-10/13 retrofit technical information

Retrofitting the withdrawable element (WE) of the KU-10C series switchgear is a technically correct replacement of the withdrawable connection trolley with a modern module for 6–10 kV networks while retaining the main part of the cell: metal body, busbars, cable approaches, and switchgear layout. This approach is used when the KU-10C cabinet is still mechanically and insulatively suitable for operation, but the “bottleneck” is in the withdrawable unit: the circuit breaker's service life is exhausted, the contact connection is unstable in terms of pressure, the adjustment does not ensure a repeatable working position, and the curtains and interlocks malfunction. As a result, replacing the VE transfers the connection to modern vacuum switching, restores the predictability of the mechanics, and simplifies further modernization of secondary circuits (RZA, signaling, arc protection, telemechanics) without reconstructing the entire switchgear.

When is replacement of the KU-10C withdrawable unit most justified?

• Switch resource: repairs become frequent, results are unstable, downtime and maintenance costs increase.
• Signs of overheating in the plug connection area: darkening/burning of contact parts, traces of heating on the insulation, “floating” transition resistance values.
• Incomplete carriage engagement: need for “re-engagement,” unstable fixation in the working position, skewing during rolling, increased backlash in kinematics.
• Failures of curtains and interlocks: incomplete closure, jamming, false locking, or lack of prohibitions on erroneous operations.
• Scheduled modernization of relay protection and automation: requires streamlining of the secondary interface, addition of shutdown circuit control, and ensuring readiness for telemechanics.

What is included in the new roll-out element: components and configuration

The KU-10C is not just a switch, but a complete connection module. To reduce the risks of “on-site adjustments,” a new roll-out element assembly is supplied in a standard project (based on the results of a specific cell inspection):

• trolley (frame) with support bases, guides/rollers, movement mechanism, and fastening;
• 6–10 kV vacuum circuit breaker with drive (spring-motor or electromagnetic — depending on operational power supply and operating modes);
• movable plug-in contacts and adapters for mating elements of the cell, designed for thermal conditions and electrodynamics;
• finishing mechanism (transfer to working position with controlled contact pressure);
• interaction units with curtains (or a curtain mechanism restoration kit — if necessary);
• set of locks and limit switches (carriage position, operation permissions/restrictions);
• secondary interface: “1:1” connector, adapter pinout or replacement of the mating part of the connector (depending on the condition of the cabinet).

Main circuits: contacting, adjustment, overheating, durability

For KU-10C, the key reliability factor is the quality of the plug connection and the repeatability of the adjustment. During retrofitting, measurable parameters are recorded that directly affect heating and service life:

• contact geometry: phase position, roll-in depth, contact travel, skew-free centering;
• contact force: the trolley must “settle” into the working position equally with each cycle, regardless of the skill of the personnel;
• transition resistance: micro-ohmmetry criteria are set (including control after several insertion/withdrawal cycles);
• Short-circuit stability: current-carrying parts, fasteners, and contact assemblies must withstand electrodynamic forces without residual deformation.

It is the “contacts + adjustment” that most often determine whether the upgrade will be durable. Therefore, the KU-10C retrofit is designed as a solution for the entire power supply unit, rather than as a replacement for the device without adjusting the connections.

Secondary circuits: connector, pinout, compatibility table

To prevent the introduction of the KU-10C power supply from turning into a lengthy “re-wiring” process, a scenario for connecting secondary circuits is selected in advance:

1. “1:1” connector — repeat of the existing connector type and pinout, minimum mounting window.
2. Transitional pinout — adapter/strip and circuit correspondence table (I/O matrix) with preserved labeling.
3. Replacement of the mating part of the connector — in case of contact wear, burnout, or expansion of functions (control of shutdown circuits, arc protection, additional telemechanics signals).

Recommended summary for the “secondary” — interface passport: pinout, list of signals, control points, and list of limit switches/block contacts involved in the logic of interlocks.

Technical data (typical)

Safety and interlocks: prevention of erroneous operations

Replacement of the KU-10C roll-out element must ensure unambiguous and verifiable safety. A typical set of functions that is incorporated and verified during retrofitting:

• prohibition of trolley movement when the switch is on;
• prohibition of switching on the switch outside the “test/operating” positions with confirmation of locking;
• correct operation of curtains: blocking access to live parts when exiting operating positions;
• “switch-trolley-door” logic and, if provided for by the design, connection to the grounding device;
• position indication and the possibility of sealing/locking in accordance with operating regulations.

Retrofit algorithm: inspection, manufacturing, installation, PNR

1. Inspection of the KU-10C cell: photos and measurements of the VE compartment, contact system, curtains, guides, fixing units, secondary connector; assessment of the condition of fixed contacts.
2. Binding project: contact adapters, finishing/stops, list of locks, secondary pinout and I/O matrix.
3. Factory assembly of the VE: adjustment of trimming and interlocks, functional checks of secondary circuits, mechanical runs.
4. On-site installation: VE installation, secondary interface connection, control measurements, curtain and interlock checks.
5. PNR and commissioning: checking switching on/off, position alarms, commands to switch off from the relay protection and automation system, and drawing up reports.

Acceptance and quality control: measurements and protocols

To prevent problems from recurring (overheating, “floating” positions, false interlocks), it is recommended to accept the KU-10C retrofit based on measurable criteria:

• micro-ohmmetry of the main circuit transition resistance (including control after several roll-in/roll-out cycles);
• checking the adjustment and fixing of the “repair/test/operating” positions with control of the limit switches;
• checking the curtains for complete closure and absence of jamming at all transitions;
• functional testing of secondary circuits: switching on/off, position signals, interlock circuits, disconnection from relay protection and automation.

The final documentation includes test reports and a list of settings (limit switches, interlocks, connector/adapter pinouts), which simplifies operation and further testing.

FAQ on KU-10C

Is it possible to replace only the switch, leaving the old trolley?
It is possible if the trolley, adjustment, contact assembly, and locks are in good condition. If there is overheating, backlash, or unstable fixation, it is safer to replace the entire switchgear.

Do the busbars and cable entries need to be replaced?
In a typical retrofit, no. The purpose of replacing the KU-10C switchgear is precisely to preserve the busbars and cable connections while updating the most worn-out unit.

We offer you documentation for replacing the KU-10C switchgear roll-out element (retrofit):

- Preliminary technical documentation for participation in tenders for the replacement of the KU-10C switchgear roll-out element (6–10 kV). We will prepare the necessary information for you to assess the possibility of manufacturing products in accordance with the requirements of the tender documentation and questionnaires.
- Working drawings, 3-D models, and other necessary documentation for the manufacture of the KU-10C switchgear roll-out element at your enterprise. If you do not plan to manufacture the product's components and parts yourself, we will help you outsource their manufacture to third-party enterprises. The final assembly and installation of the product will be carried out at your facility.
- All documentation will be adjusted as necessary in accordance with the project requirements and the technological capabilities of your facility.
- If equipment from another manufacturer is installed at the substation, we will prepare documentation for the manufacture of similar equipment in addition to the installed equipment.

Advantages of working with us:

- The KU-10C retrofit project is built around critical parameters: contacting, fine-tuning, curtains, interlocks, and secondary interfaces are formalized as measurable and verifiable criteria.
- Downtime is minimized thanks to factory preparation of the assembled power equipment and a pre-designed circuit compliance table.
- As a result, you receive a KD/3D package and a quality control methodology (micro-ohmmetry, interlock verification, pinout passport), which increases operational predictability.

For more information on replacing the KU-10C switchgear roll-out element (retrofit), please contact: inbox@proekt-energo.com

PDF - Download technical information on replacing the KU-10C roll-out element

Page content

• What tasks is the KVVO retrofit suitable for?
• KVVO chamber design and the role of the roll-out element
• What exactly changes when replacing the VE (nodes and interfaces)
• Compatibility with existing cell: main circuit, curtains, mechanics
• Secondary circuits: connector, pinout, diagnostics of shutdown circuits
• Technical data (typical)
• Safety: interlocks, trolley positions, elimination of erroneous operations
• Acceptance and measurements: what to check before commissioning
• Options: arc protection, relay protection terminals, monitoring, integration into the automated control system

What tasks is KVVO retrofitting suitable for?

• Extending the service life of 6–10 kV KVVO chambers without replacing cabinets and without interfering with the busbar space.
• Replacement of obsolete circuit breakers and drives when repairs are ineffective or standard components are unavailable.
• Elimination of overheating of plug connections and restoration of repeatable adjustment/fixing of the trolley.
• Restoration of operational safety through correct curtains, interlocks, and clear locking logic.
• Preparation for digitalization: streamlining secondary circuits, introducing shutdown circuit control, expanding signaling, and preparing for telemechanics.

KVVO chamber design and the role of the roll-out element

KVVO refers to roll-out type indoor chambers with one-sided maintenance. The chamber is structurally divided into functional compartments (busbar, relay/instrument, roll-out trolley compartment, and plug connections/auxiliary devices compartment). In this architecture, the VE is the “center” of connection: it simultaneously provides main circuit switching, mechanical linkage with curtains and interlocks, as well as connection of secondary circuits via plug connectors. Therefore, KVVO retrofitting must solve the problem comprehensively: switch + contact system + adjustment + interlocks + secondary interface, and not just replacement of the device.

What exactly changes when replacing the VE (nodes and interfaces)

In a typical project to replace a KVVO roll-out element, a new roll-out element assembly (or upgrade module, depending on the results of the inspection) is supplied, including:

• trolley (frame) with guides/wheels and position locking unit;
• a modern 6–10 kV vacuum circuit breaker with a drive (spring-motor or electromagnetic — depending on the operational power supply and technical specifications);
• primary plug-in contacts (movable part) and adapters for the mating contacts of your KVVO chamber;
• finishing mechanism (transition to the “working” position with the required contact pressure) and locking control elements;
• shutter interaction units (or a set of updated shutter parts, if required based on the actual condition);
• limit switches and interlocks (set of mechanical/electrical locks);
• secondary interface: compatible connector or adapter/replacement for the mating connector.

Compatibility with existing cell: main circuit, curtains, mechanics

To prevent the KVVO retrofit from turning into a “fit on site,” four compatibility interfaces are specified in the project:

1. Power: plug connection geometry, insertion depth, phase alignment, contact travel, dielectric distances, and permissible heating.
2. Kinematic: guides, stops, adjustment, and fixing of trolley positions. Repeatability is important: the trolley must fit into the “test/working” position without play or misalignment.
3. Curtain: guaranteed closure of the current-carrying part when rolling out, no jamming, correct access blocking in case of incorrect sequence of actions.
4. Logical: coordination of “switch-cart-door” locks and, if provided for in your chamber, “switch-cart-grounding knife” locks.

In practice, the most common cause of overheating in old KVVO devices is a combination of wear on contact parts and insufficient trolley adjustment. Therefore, when replacing the VE, the priority is not only the “switch rating” but also reproducible adjustment with a specified contact force.

Secondary circuits: connector, pinout, diagnostics of shutdown circuits

KVVO cameras typically use plug connections, so correct connection of secondary circuits is critical for quick commissioning. We use one of three approaches (the choice depends on the condition of the cabinet and the objectives of the retrofit):

• 1:1 connection — full compatibility of the connector and pinout with existing control and signaling circuits.
• Transitional pinout — adapter/strip + circuit compatibility table, allowing you to keep the markings and avoid errors during installation.
• Replacement of the mating part of the connector — in case of contact wear or function expansion: control of shutdown circuits, additional readiness signals, arc protection input, integration into telemechanics.

Recommended result for secondary circuits — “interface passport”: pinout, list of signals, control points, participation of limit switches in interlocks, and a list of actual changes relative to the original diagram.

Technical data (typical)

Safety: interlocks, trolley positions, elimination of erroneous operations

Replacement of the KVVO roll-out element should not simply “turn on and off,” but ensure unambiguous switching safety. The retrofit includes the implementation and testing of:

• prohibition of trolley movement when the switch is turned on;
• prohibition of switching on the switch outside the “test/operating” positions;
• correct operation of the curtains when switching between positions;
• door/access lock depending on the position of the trolley and the connection status;
• connection to the grounding knife (if provided by your chamber) and exclusion of conflicting positions.

Acceptance and measurements: what to check before commissioning

To reduce the risk of overheating and “floating” locks, it is recommended to accept the KVVO retrofit based on the following measurable criteria:

• micro-ohmmetry of the transition resistance of the main circuit after several roll-in/roll-out cycles (contact repeatability control);
• checking the adjustment and fixing of the “repair/test/operating” positions, including limit switches and enabling contacts;
• checking the curtains for complete closure and absence of jamming in all transitions;
• functional checks of secondary circuits: switching on/off, position signaling, interlock circuits, commands to disconnect from the relay protection and automation system.

The result is protocols, a settings sheet (limit switches/interlocks), and a secondary interface passport, which simplifies further operation and connection status auditing.

Options: arc protection, relay protection terminals, monitoring, integration into the automated control system

• arc protection (optical sensors + current criterion) with fast disconnection of the connection;
• replacement/modernization of relay protection and automation with microprocessor terminals (MTZ, ZZ, directional stages, UROV, APV — according to the project);
• circuit breaker monitoring: operation counter, drive readiness control, extended diagnostic signals;
• integration into ACS/SCADA (remote signaling/remote control) via a terminal or gateway — according to facility requirements.

We offer you documentation for replacing the KVVO switchgear roll-out element (retrofit):

- Preliminary technical documentation for participation in tenders for the replacement of the KVVO switchgear roll-out element (6–10 kV). We will prepare the necessary information for you to assess the possibility of manufacturing products in accordance with the requirements of the tender documentation and questionnaires. - Working drawings, 3-D models, and other necessary documentation for manufacturing the KVVO switchgear roll-out element at your enterprise. If you do not plan to manufacture the product's components and parts yourself, we will help you outsource their manufacture to third-party enterprises. The final assembly and installation of the product will be carried out at your facility.
- All documentation will be adjusted as necessary in accordance with the project requirements and the technological capabilities of your facility.
- If equipment from another manufacturer is installed at the substation, we will prepare documentation for the manufacture of similar equipment in addition to the installed equipment.

Advantages of working with us:

- The retrofit is “tied” to your KVV chamber: the contact system, fine-tuning, curtains, locks, and secondary interface are set as controlled parameters, not as “on-site adjustments.”
- The risks of overheating and unstable positions are reduced by mandatory micro-metrology, adjustment protocols, and certification of secondary circuits.
- Step-by-step modernization is possible: first, reliable VE, then arc protection/RZA/telematic according to the project.

For more information on replacing the KVVO switchgear roll-out element (retrofit), please contact: inbox@proekt-energo.com

PDF - Download technical information on replacing the KVVO roll-out element

Retrofitting the K3-02 switchgear draw-out element involves replacing the draw-out connection trolley (VET) with a modern module for 6–10 kV networks while retaining the main part of the cell: the housing, busbars, cable entries, and compartment layout. In practice, K3-02 is modernized not “for the sake of replacing the switch,” but for the sake of restoring the controllability and safety of the connection: stabilization of the contact node, repeatability of adjustment, correct operation of curtains and locks, as well as for transferring switching to vacuum technology. Properly performed replacement of the switchgear allows to extend the service life of the cell without major reconstruction of the switchgear and without remodeling the busbar space, while significantly reducing operational risks.

Contents (quick jump)

• Key queries and purpose of the K3-02 retrofit
• When is it necessary to replace the K3-02 withdrawable unit?
• K3-02 roll-out element: component structure and what actually changes
• Main circuit: contacting, adjustment, thermal mode
• Secondary circuits: connector, pinout, control logic
• Locks and safe sequence of operations
• Technical data (typical for 6–10 kV)
• How retrofitting is performed: stages of work and shutdown window
• Quality control: measurements, protocols, acceptance criteria
• Typical mistakes when replacing power equipment (and how to avoid them)

Key queries and purpose of the K3-02 retrofit

This page focuses on practical operational and procurement queries: ”K3-02 6 kV retrofit“, ”K3-02 10 kV roll-in trolley“, ”replacement of K3-02 low-oil switch with vacuum switch", “replacement of K3-02 roll-out element without replacing the switchgear”. The purpose of the solution is to quickly and technically correctly upgrade the 6–10 kV roll-out connection module, preserving the cabinet but eliminating the causes of overheating, lock failures, unstable adjustment, and labor-intensive repairs of the switch.

When replacement of the K3-02 withdrawable unit is required

• The circuit breaker's service life has expired: increased failures, increased maintenance time, degradation of drives and block contacts, no predictable result after repair.
• Overheating of the plug-in unit: signs of thermal impact, darkening/burning of contact parts, increased contact resistance, need to “press” the trolley into the working position.
• Unstable trolley mechanics: backlash, skew when rolling in, floating “test/working” positions, non-fixable adjustment.
• Problems with curtains and interlocks: incomplete closure of openings, jamming, false prohibitions or lack of prohibitions on erroneous operations.
• Need to upgrade secondary systems: introduction of arc protection, relay protection terminals, remote signaling/remote control, shutdown circuit monitoring.

K3-02 withdrawable element: composition of nodes and what actually changes

The K3-02 withdrawable unit is a functional connection module. Reliability depends not only on the circuit breaker, but also on the “interfaces” (contacts and mechanics). As part of the retrofit, a new retractable element assembly is usually formed, including:

• Trolley (frame) with bases and guides that ensure repeatable roll-in geometry without skew.
• 6–10 kV vacuum circuit breaker (alternative — SF6 according to technical specifications) with drive and set of block contacts; the project specifies APV modes, requirements for operational power supply and readiness signals.
• Primary plug-in contacts (movable part) and adapters for mating elements of a specific K3-02 cell — this assembly determines the heating and resistance to short-circuit dynamics.
• Adjustment and locking mechanism — ensures transition to the “working” position with controlled contact pressure and eliminates under-adjustment.
• Curtain mechanism (or elements interacting with the cabinet curtains) for automatic closure of the current-carrying part openings when exiting the working positions.
• Interlocking system (mechanical/electrical) and limit switches — a key factor for safe switching and proper maintenance.
• Secondary interface: connector/terminal module, transition solutions, marking, and circuit compatibility table.

Main circuit: contacting, fine-tuning, thermal mode

The critical node of the K3-02 retrofit is the plug-in connection of the main circuit. If the contact is “assembled on site” without specified parameters, problems usually return after one or two seasons of operation. The following are fixed in the binding project:

• contact geometry: phase position, roll-in depth, contact assembly travel, absence of skew along the trajectory;
• contact force: required pressure and repeatability of adjustment (without “pressing with a crowbar” and without dependence on staff skills);
• thermal regime: checking heating according to calculations and monitoring contact resistance (micro-ohm meter) after several insertion/withdrawal cycles;
• short-circuit resistance: fasteners, current-carrying parts, and contact assemblies must withstand electrodynamic forces without residual deformation.

For cells where low-oil circuit breakers were previously used, retrofitting usually involves switching to vacuum switching with simultaneous “normalization” of the contact assembly — this is what provides the main effect in terms of reliability.

Secondary circuits: connector, pinout, control logic

Errors in secondary circuits are one of the most common reasons for prolonged commissioning after replacing the switchgear. There are three practical connection scenarios for K3-02:

1. 1:1 compatibility — the existing connector and pinout are retained (ideal if the cabinet has not been modified haphazardly).
2. Transitional pinout — an adapter/strip is installed, a circuit correspondence table (I/O matrix) is formed, and the marking is retained.
3. Replacement of the mating part of the connector — relevant in case of contact wear, burning, or when expanding functions (control of shutdown circuits, arc protection, additional telemechanics signals).

Recommended rule: any modernization of the “secondary” must be completed by issuing a secondary interface passport (pinout, list of signals, control points, participation of limit switches in the logic of interlocks).

Interlocks and safe sequence of operations

Retrofit K3-02 must ensure a clear sequence of actions by personnel. A typical set of functions built into the VE:

• prohibition of trolley movement when the switch is on;
• prohibition of switching on the switch outside the “test/operating” positions with confirmation of fixation;
• exclusion of access to live parts in inappropriate positions (curtains + mechanical/electrical prohibitions);
• control of the end positions of the trolley and output of correct signals to the relay protection and automation system/telemetry;
• possibility of sealing/locking in accordance with operating regulations.

If a particular cell configuration has an earthing switch, the “trolley-switch-earthing switch” interlocks and restrictions on the sequence of operations are linked to exclude conflicting positions.

Technical data (typical for 6–10 kV)

How the retrofit is performed: stages of work and shutdown window

To reduce connection downtime, it is advisable to organize the project so that all complex operations are performed before the cell is shut down:

1. Inspection of K3-02: photo documentation, measurements, identification of the contact system, assessment of the condition of fixed contacts, curtains, interlocks, and secondary connectors.
2. VE binding project: contact adapters, kinematics of adjustment, limit switches and locking logic, secondary circuit correspondence table.
3. VE manufacturing/assembly: adjustment of the adjustment mechanism, checking of curtains and interlocks, functional testing of secondary circuits.
4. Installation: installation of the VE, connection of the secondary interface, control measurements, verification of positions and interlocks.
5. PNR: checking interaction with RZA, correctness of shutdown/signaling, drawing up protocols.

Quality control: measurements, protocols, acceptance criteria

For K3-02, it is recommended to accept retrofits based on measurable criteria directly related to reliability:

• micro-ohm measurement of the transition resistance of the main circuit after several roll-in/roll-out cycles;
• checking the adjustment and fixing of the “repair/test/operating” positions (including limit switches and enabling contacts);
• checking the curtains and interlocks for correct sequence of operations;
• functional check of secondary circuits: switching on/off, position signals, interlock circuits, commands to disconnect from the relay protection and automation system.

The result is protocols and a list of settings (limit switches, interlocks, pinouts) that make further operation predictable and repeatable.

Common mistakes when replacing power equipment (and how to avoid them)

• Mistake 1: “fitting contacts on site” instead of design reference. Solution: fix the geometry, pressure, and micro-metric criteria before installation.
• Mistake 2: ignoring fine-tuning (the carriage seems to have “arrived,” but has not entered the mode). Solution: separate adjustment and position fixing protocol, repeatability check.
• Error 3: secondary circuits without an I/O matrix. Solution: a circuit correspondence table and secondary interface passport are mandatory.
• Error 4: curtains “will work somehow”. Solution: check for complete closure, no jamming, check interlocks on all transitions.

We offer you documentation for replacing the K3-02 roll-out element (retrofit):

- Preliminary technical documentation for participation in tenders for the replacement of the K3-02 roll-out element (6–10 kV). We will prepare the necessary information for you to assess the possibility of manufacturing products in accordance with the requirements of the tender documentation and questionnaires.
- Working drawings, 3-D models, and other necessary documentation for manufacturing the K3-02 roll-out element at your enterprise. If you do not plan to manufacture the product's components and parts yourself, we will help you outsource their manufacture to third-party enterprises. Your enterprise will perform the general assembly and installation of the product.
- All documentation will be adjusted as necessary in accordance with the project requirements and the technological capabilities of your enterprise.
- If equipment from another manufacturer is installed at the substation, we will prepare documentation for the manufacture of similar equipment in addition to the installed equipment.

Advantages of working with us:

- The retrofit is tied to a specific modification of K3-02: the contact system, fine-tuning, curtains, interlocks, and secondary interface are designed as a controlled technical solution.
- For 6–10 kV, key risks are covered by measurements: micro-ohmmetry of the main circuit, lock adjustment protocols, and connector pinout certification.
- Step-by-step modernization is possible: replacement of the VE (quick effect on reliability) + implementation of arc protection/RZA terminals/telemetry according to the project.

For more information on replacing the K3-02 roll-out element (retrofit), please contact: inbox@proekt-energo.com

PDF - Download technical information on replacing the K3-02 roll-out element