Application and Scope

The single-pole indoor disconnector RVO-10 is intended to provide a visible break and safe reconfiguration of busbar and feeder sections in 6–10 kV switchgear with no load current present. RVO series devices perform operational isolation, scheme changeover, equipment outage for maintenance, and fault localization while ensuring a clearly visible isolation gap. Thanks to its compact single-pole design, the RVO is convenient for use in KSO single-side-access cubicles, KRU/KRUN metal-enclosed switchgear, medium-voltage main switchboards, incoming and tie cubicles, transformer/reactor connection cubicles, busbars, and bypass links.

Beyond classic switchgear, the RVO disconnector is widely used for switching coupling capacitors of SMP/SMPV types (power-line carrier channels for telecontrol and protection) to connect high-frequency paths to 6–10 kV primary circuits and to interface with communications equipment at 110 kV substations. Dedicated versions are optimized for in-line installation within capacitor banks, static VAR compensator circuits, as well as in measuring circuits (e.g., at voltage-transformer portals).

Within a switchgear lineup the RVO provides: 1) safe isolation of the section under maintenance; 2) the possibility for personnel to apply portable earthing devices after de-energizing; 3) convenient inspection of current-carrying parts thanks to an open, visible isolation gap. Depending on the installation location, RVO disconnectors are mounted on frames, panels, or inside cubicles via the base (pedestal) and allow longitudinal or transverse orientation relative to the busbars.

Технические данные

Operating Conditions

Baseline environmental category: EN/IEC 60721-3-3 (indoor, weather-protected; comparable to GOST 15150 UHL2). Operation is intended in enclosed rooms with natural ventilation and without special HVAC control. Temperature range and humidity requirements correspond to indoor weather-protected environments per EN/IEC 60721-3-3. Operation is permitted up to 1000 m above sea level without derating of insulation levels, provided there is no conductive dust and no corrosive vapors in concentrations that would attack current-carrying parts.

The disconnectors are designed for 50 Hz networks and 6 or 10 kV (maximum operating voltage 7.2/12 kV). With respect to environmental effects, short-term vibrations typical for switchgear equipment (e.g., during adjacent operations) and transport loads are acceptable when packaging and storage rules are observed. For areas with elevated dust, condensation, or extended maintenance intervals, special insulators, increased creepage distances, and protective coatings for current-carrying parts can be applied on a project basis.

Layout and Design Features

The RVO disconnector comprises a base (frame), support insulators, and a contact system. The base serves as the foundation for the insulators and for fastening the device inside a cubicle or on a panel; both bolted and welded attachment to the cabinet’s structural members are possible. Support insulators are selected by voltage class and mechanical/electrical strength; porcelain or composite versions with enhanced pollution performance can be supplied on request.

The contact system is of the knife type and consists of two fixed box contacts and a rotating contact blade. The blade is linked to an operating shaft rotated by an insulating rod or an integrated lever mechanism. The geometry of contact surfaces and the contact pressure ensure low transfer resistance, minimal wear, and stability against electrodynamic forces during short-circuit currents. Corrosion-resistant plating is applied; silver-tipped contact surfaces are available on request for improved durability.

In the closed position the blade is latched by a special magnetic latch or mechanical pawl. The latch prevents inadvertent opening due to blade weight, shocks/vibration, or electrodynamic forces under short-circuit conditions. The latch features an eye for engaging the tip of an insulating operating rod, providing controlled opening/closing and secure fixation. The opening angle is limited by a stop on the axial-contact bracket; when the angle exceeds 75°, a clear visible isolation gap is formed.

Terminal assemblies accept copper or aluminum busbars, flexible connectors, and cable lugs. Options include in-line or angled take-offs, transition plates, and on-site match-drilling to align with standard busbar elevations in KSO/KRU lineups. A mechanical position indicator can be fitted; provision for a position microswitch to signal into SCADA/DCS is available on request.

Safety and Interlocking

The design incorporates occupational-safety requirements and typical interlocks used in medium-voltage switchgear. The standard configuration provides: 1) a visible break in the open position; 2) end-stops preventing incomplete opening/closing; 3) holes for padlocking in the “Closed”/“Open” positions (depending on version); 4) the ability to prevent access via mechanical linkage to the cubicle doors; 5) compatibility with typical interlocks on load-break switch and contactor mechanisms (as defined by the cabinet design). When working de-energized, portable earthing devices may be applied on the nearest busbars per local safety rules and work instructions.

Versions and Options

The RVO family covers rated currents of 400, 630, and 1000 A for 6 and 10 kV classes. Baseline environmental category - EN/IEC 60721-3-3 (indoor, weather-protected). On request:

• Contact system variants: copper contacts with corrosion-resistant plating; on request - silver-tipped contact areas;
• Selection of support insulators for pollution conditions: porcelain ИО-10-3,75 У3 / ИОР-10-3,75 УХЛ2, and for increased reliability - outdoor-duty insulators (e.g., ИОС-10/500 УХЛ1) to special order;
• Connection variants: flat/angled, with transition bus plates, for M12–M16 bolting;
• Prepared mounting points for position sensors and interlocks with adjacent devices;
• Base/frame finish matched to cabinet color scheme; marking, labels, nameplates in Russian/English.

Comparable Solutions and Use Cases

Alongside single-pole RVO-type disconnectors, modern KSO/KRU lineups also employ three-pole vertical-break and rotary devices (for example, the GN38/GNF38 series for 12 kV with a three-position mechanism “On–Off–Earthing”). Three-pole solutions are convenient when all phases must be operated simultaneously and a fixed earthing switch is required. The single-pole RVO excels where modularity, flexible layout, individual phase reconfiguration, and integration into specialized cubicles are critical (HF coupling-capacitor circuits, power-flow re-routing on ties, bypass schemes).

The RVO indoor disconnector is intended for switching energized circuit sections in the absence of load current, for changing connection schemes, and for safe work on de-energized sections. RVO disconnectors are also used to switch coupling capacitors of SMP/SMPV type for a rated voltage of 110 kV.

The single-pole RVO disconnector consists of a base, support insulators, and current path. The base serves to mount the insulators and to fasten the device. The current path comprises two fixed contacts and a movable knife contact connecting them.

In the closed position, the knife is held by a special magnetic latch or pawl, so inadvertent opening due to electrodynamic forces, the blade’s own weight, or vibration is excluded. The magnetic latch or pawl has an eye to engage the tip of a manual insulating rod during opening and closing. Opening beyond 75° is limited by a stop on the axial-contact bracket.

Standards Compliance

In design and manufacture of the RVO series, the following norms and terminology are considered (for use within MV switchgear and for the disconnector function):

• IEC 62271-102 - AC disconnectors and earthing switches (requirements for disconnectors);
• IEC 62271-1 - Switchgear and controlgear - Part 1: Common specifications (general requirements for equipment above 1 kV);
• IEC 62271-200 - AC metal-enclosed switchgear and controlgear for 1–52 kV (for KSO/KRU/KRUN assemblies in which the RVO operates);
• EN/IEC 60721-3-3 - Environmental conditions - Classification for stationary use at weather-protected locations (applied for indoor environmental category comparable to GOST 15150 UHL2);
• Customer/Project-specific requirements (to be fixed in the product specifications/manual for the particular item).

Cooperation with Contractors, Manufacturers, and Investors

We welcome cooperation with manufacturers, integrators of 6–10 kV switchgear, metalwork, and insulator suppliers. A phased rollout is offered: audit of your plant capabilities, adaptation of design documentation to your equipment, supplier chain selection (insulators, contact materials, hardware), organization of assembly and testing, personnel training, and site supervision on initial projects. For investors - typical financial models for launching a product line, including batch cost, break-even point, and ramp-up schedule.