The RVR-20/8000 and RVRZ-20/8000 indoor disconnectors are intended for isolating and reconnecting de-energized sections of an electric circuit in medium-voltage systems while the installation remains live (no load current), as well as for earthing such sections by means of fixed earthing switches.
By design, the vertical-break type disconnectors are manufactured in single-pole execution.
RVR units are supplied without an earthing switch; RVRZ units are supplied with an earthing switch on either the separable-contact side or the non-separable-contact side.
RVR/RVRZ disconnectors consist of a base frame, support insulators, contact system, pull-rod (operating) insulator and earthing switches. A drive shaft with levers mounted on the frame operates the moving blades. If earthing switches are fitted, one or two additional shafts are provided to operate them, together with a mechanical interlock that prevents closing the earthing switch when the main blades are closed, and vice versa. The insulation set comprises support and operating insulators. The contact system comprises fixed copper contacts and moving copper blades. To reduce opening and closing torque, a contact-pressure relief mechanism is used (cam and latching assemblies). The earthing switches comprise a copper bar fixed to steel uprights welded to the earthing-switch shaft. When the earthing switch is closed the bar enters lamellar contacts mounted on the lower shelves of the fixed main contacts. Contact pressure in the axial and separable main contacts and in the earthing lamellae is provided by springs.
RVR/RVRZ disconnectors are intended for operation in indoor switchgear under the following environmental conditions:
– altitude not exceeding 1000 m;
– maximum ambient temperature +40 °C;
– minimum ambient temperature -45 °C;
– relative humidity 80% at +20 °C.

Technical data

Purpose and application

RVR-20/8000 and RVRZ-20/8000 are high-current, vertical-break disconnectors for 20 kV medium-voltage systems with an exceptionally high rated current up to 8,000 A. They are used to isolate and provide a visible break in busbars and feeders without shutting down the entire switchgear lineup. Typical applications include busbar sectioning in metal-enclosed switchgear (KRU) and gas-insulated switchgear (GIS), transformer incomers/outgoers, bypass and maintenance links at primary substations, high-current auxiliary bus systems in power plants and metallurgical facilities, and busduct nodes in industrial power supply centers.
The disconnectors may be operated under voltage without load current and, when equipped with motor drives and interlocks, provide safe earthing of the isolated sections prior to work. The single-pole design allows flexible arrangement on site: building three-phase groups, bus sectioning, or adding bypass blades.

Service conditions

Designed for indoor installation at electrical stations and substations free from conductive dust, aggressive gases and vapors, in non-hazardous environments. Environmental classification per EN/IEC 60721-3-3 (stationary use at weather-protected locations). Operating ambient temperature from -45 °C to +40 °C; relative humidity up to 80% at +20 °C; installation altitude up to 1000 m above sea level. Seismic capability can be provided by project when installed on appropriate foundations. The degree of protection for live parts is determined by the switchgear/cubicle design; drives and interlocks are typically no less than IP20/IP21. Applicable for use in compartmentalized switchgear cells (KSO), metal-enclosed switchgear at 6–20 kV, and special bays of primary substations with forced ventilation. High current duty requires superior contact quality and cooling: low contact resistance is ensured and permissible temperature rise is calculated considering natural convection and busbar thermal conductivity. For dusty or humid rooms, periodic inspection of bolted joints and torque control per maintenance schedule is recommended.

Layout and construction

The disconnector is built on a welded steel frame with anti-corrosion coating. Support insulators (porcelain or composite) provide high mechanical strength and creepage distance suited to the site pollution level. The moving assembly is a vertical-break copper blade with silver-plated contact surfaces. Blades are rigidly linked to the drive shaft via a lever-cam mechanism that provides a fast break and stable contact pressure in the CLOSED position while reducing the drive torque during operation.

Fixed contacts are multi-lamellar, spring-loaded (copper alloy lamellae with silver coating) for reliable performance at 8,000 A continuous current and short-circuit duties. Busbar connections are via flat copper terminals drilled for standard hardware; flexible copper shunts can be supplied to compensate thermal expansion. Reduced heating is achieved by enlarged contact areas, optimized blade/lamella geometry and minimizing separable joints in the current path. The contact-pressure relief mechanism (cam/latch) decreases wear and operating effort while maintaining the required pressure in service.

The earthing switch (RVRZ versions) is mounted on the common base and operated by a dedicated shaft. Its copper bar engages lamellar contacts installed on the lower shelves of the main fixed contacts, ensuring low resistance and high making/withstand capability under short-circuit conditions. Shafts of the disconnector and earthing switch are equipped with local position indicators «ON/OFF/EARTHED» and allow mounting of limit switches for SCADA signaling.

The kinematic system is rated for a mechanical endurance of at least 2,000 O–C cycles while maintaining contact pressure and spring integrity. All fasteners are secured against loosening (cotter pins/locking elements). Corrosion protection includes powder-coated frame parts and tin/silver galvanic coatings on current-carrying parts to minimize contact resistance and oxidation.

Safety and interlocking

An independent mechanical interlock is implemented between the main blade and the earthing switch: closing the earthing switch with the disconnector closed is prevented, as is closing the main blades with the earthing switch closed. The interlock is shaft-mounted with positive mechanics and allows sealing/padlocking. For integration into safety schemes, the following are provided:

• electrical interlocks (limit switches with changeover contacts for control circuits);
• key interlocks (on request) to enforce the operating sequence;
• local mechanical indication and provision for duplicate “DANGER - LIVE/EARTHED” tags;
• travel stops and dampers to reduce impact loads.

Versions and options

The base range includes a version without earthing switch (RVR) and a version with earthing switch (RVRZ). Single-pole construction allows configuring three-pole groups using coupling rods and synchronizing shafts. Drives can be manual rotary or motorized with remote control. On request: mirrored earthing-switch location (left/right), terminal kits for various bus widths and flexible shunts, additional auxiliary contacts, and position sensors for SCADA integration.

Materials and endurance

Compliance with standards

Design and testing are oriented to the requirements for medium-voltage switchgear and controlgear:

• IEC 62271-1 - Switchgear and controlgear, common specifications;
• IEC 62271-102 - Alternating-current disconnectors and earthing switches;
• IEC 62271-200 - A.C. metal-enclosed switchgear and controlgear rated 1–52 kV;
• EN/IEC 60721-3-3 - Environmental classification, stationary use at weather-protected locations;
• EN/IEC 60721-3-4 - Environmental classification, stationary use at non-weather-protected locations (if applicable).

Engaging manufacturers and contractors

We are open to cooperation with mechanical plants, switchgear OEMs, installation and service companies. We provide licensable working documentation for manufacturing RVR/RVRZ disconnectors at your facilities, including material specifications and standard process sheets. We assist in organizing production of sub-assemblies (bending and brazing copper bars, lamellar contacts, machining, surface finishing), and in conducting validation and type tests per program and procedures. For investors and developers we offer production localization support, supplier selection, cost modeling and equipment upgrades. For SCADA integrators - drive data sheets, limit-switch interfaces and signaling/control I/O.

Documentation supplied for design and manufacturing

On request we supply: 3D models (Parasolid, STEP), assembly/part drawings and BOMs (DWG/DXF), CAD assemblies for AutoCAD/SolidWorks, lists of purchased items and materials, interlock and kinematics schemes, installation & maintenance manuals, product passports and delivery specifications. Customization to a particular project is available (compartment size, bus width, drive orientation), as well as guided launch of a pilot production batch without building a prototype - based on proven solutions and thermal/electrodynamic calculations.

Benefits of working with us

– No need to maintain a large team of highly specialized engineers - you receive a complete manufacturing package that can be handled by a mid-level engineer.
– No need to build physical prototypes - our experience enables successful launch of serial batches directly from documentation.
– Working to our documentation, your team receives consulting on all nuances of RVR-20 assembly (layout, kinematics, contact-pressure control, interlock adjustment, test preparation).

For additional information on RVR-20/8000 and RVRZ-20/8000 disconnectors, please contact: inbox@proekt-energo.com

... and, as is well known, an error made at the design stage turns into 10× costs in manufacturing and 100× in operation...

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