RG-type disconnectors are intended for switching on and off off-load sections of medium-voltage circuits up to 35 kV, as well as for earthing disconnected sections by means of built-in earthing switches. The disconnectors are available in single-pole, double-pole and three-pole versions. The pole connected to the operating mechanism is the driving pole. Operating mechanisms are used to operate the disconnectors. Rotation of the main-circuit shaft and the earthing-switch shaft is performed manually using PR-2B or PRG mechanisms, or with the PD-14 motor drive.
Disconnectors are manufactured for outdoor service according to EN/IEC 60721-3-4 (stationary use at non-weather-protected locations), with the following service conditions:
- altitude up to 1000 m a.s.l.;
- upper ambient temperature +40 °C;
- lower ambient temperature -60 °C; 
- wind speed up to 40 m/s without icing and up to 15 m/s with ice accretion up to 10 mm;
- average annual relative humidity 80% at +15 °C;
- maximum wind pressure 700 Pa (equivalent to wind speed 34 m/s) without icing;
- maximum wind pressure 140 Pa (equivalent to wind speed 15 m/s) with ice accretion up to 10 mm;
- maximum combined mechanical load on the terminals of one pole (from connected conductors including wind and ice) - 500 N, provided the load is evenly distributed among the terminals.
The dielectric withstand of the insulation meets the requirements for 35 kV-class medium-voltage disconnectors in accordance with EN/IEC 62271-1 and EN/IEC 62271-102. Creepage distance of the external insulation for porcelain insulators:
- for pollution level I - at least 70 cm;
- for pollution level II - at least 105 cm.
On request, RG units can be supplied on polymer insulators (type OSK) with creepage distance not less than 105 cm. Mechanical endurance - 2000 operating cycles (close–open).
The disconnectors are not intended for service under severe shock, vibration or impacts.

Technical data

Purpose and application

RG-35 is a medium-voltage outdoor switching device with a visible isolating distance. It is used for operational reconfiguration of bus/line schemes and for safe isolation of equipment for maintenance. Typical applications: outdoor air-insulated switchyards (AIS) at 35 kV substations, line and incoming bays, bus-section and bypass disconnectors, switching of shunt reactors and capacitor banks, line taps and sectioning points. RG-35 disconnectors permit switching of transformer no-load currents and charging currents of overhead and cable lines, as well as earthing of disconnected network sections by built-in earthing switches where fitted. Owing to the horizontal-rotary kinematics, the mechanism provides low operating torque, stable contact pressure and fast operation, which reduces wear and increases service life.

The apparatus is widely used for substation refurbishments: pole mounting dimensions and base levels allow installing new disconnectors on existing steelwork, minimizing additional structures and cabling works. Where required, disconnectors are equipped with remote operating drives and signalling circuits for integration into SCADA/DCS.

Service conditions

The disconnector is designed for outdoor service per EN/IEC 60721-3-4. Components are corrosion-protected: hot-dip galvanizing of steel frames and links, anodizing/nickel-plating of critical parts, and anti-corrosion finishes on contact surfaces. The bearing units of the support-and-turning insulators are sealed against dust and moisture, allowing operation in areas with high dust levels and condensation. The design drains melt and rainwater, preventing formation of ice “locks” along the blade travel paths.

RG-35 withstands short-term wind loads, ice accretion up to 10 mm, solar radiation, hoarfrost and temperature swings. For areas with increased airborne pollution (industrial zones, marine coasts), polymer insulators with increased creepage distance and additional grading shields can be used to improve lightning/impulse performance. The contacting system is suited for repeated short-time duty and allows multiple daily operations without deterioration of contact pressure.

Design and construction

Each RG-35 pole is a two-post design with horizontal rotation of the contact blades. A pole includes the main current-carrying path, support/rotating insulators, base frame, earthing switch assembly (if fitted), and the system of links and levers. The blades are made of high-conductivity copper bars with laminated spring contacts made of bronze alloy; working surfaces are silver- or tin-plated to reduce contact resistance and increase corrosion resistance. Positions “CLOSED/OPEN” are fixed by cam stops and mechanical latches in the drive; clear over-center “clicks” and stable holding in the end positions prevent self-movement due to wind-induced vibration.

The pole kinematics are in-phase: the driving pole is connected to the operating mechanism via the main shaft and transmits motion to the two driven poles by inter-pole links. The earthing switch has a separate kinematic chain with mechanical interlocks excluding simultaneous closing of the main circuit and the earthing switch. Bus connection terminals are flat pads suitable for tubular or bar conductors; blade-to-blade or blade-to-contact orientation can be supplied to suit the switchyard scheme. Load-bearing assemblies are designed to withstand electrodynamic forces under short-circuit currents, and the insulation - lightning and switching impulses.

For ease of installation, slotted adjustment holes and angular position scales are provided on the levers. The units are shipped in large sub-assemblies with factory pre-alignment to shorten on-site assembly time and reduce special tooling needs. All moving joints are long-term lubricated; routine maintenance is limited to periodic inspection, checking fastener torque and cleaning insulators.

Typical versions and scope of supply

Compatible drives and kinematics

Safety and interlocking

To prevent mal-operations, mechanical interlocks are provided between the main circuit and the earthing switch. Closing of the earthing switch is possible only with the disconnector fully open; closing of the disconnector with the earthing switch closed is mechanically blocked. The drives provide sealing devices and padlocking in the end positions. Limit switches are provided to send “CLOSED”, “OPEN” and “EARTHED” status signals to protection and SCADA systems. The visible isolating distance ensures personnel safety during maintenance.

The design meets electrical safety requirements for protective earthing of the frame and drives; all non-current-carrying metallic parts have dedicated connection points for the protective conductor. Current-carrying joints are rated for the specified short-time thermal and electrodynamic withstand currents, as confirmed by type tests. The operating manual includes switching procedures, routine checks and personnel requirements.

Standards compliance

• EN/IEC 62271-102 - AC disconnectors and earthing switches.
• EN/IEC 62271-1 - Common specifications for medium-voltage switchgear and controlgear.
• EN/IEC 60060-1 - High-voltage test techniques.
• EN/IEC 60721-3-4 - Environmental conditions classification for stationary use at non-weather-protected locations (outdoor).
• EN/IEC 60815 - Selection and dimensioning of insulators for polluted conditions.

Operational advantages

• Easy access to assemblies for inspection and maintenance; minimal routine servicing.
• Reliable laminated contact system with high lifetime and low contact resistance.
• Horizontal-rotary kinematics with low operating torque and stable end-position latching.
• Compatibility with standard drives and dispatching/control systems.
• Adaptation to existing structures and schemes without major steelwork modifications.

We can provide documentation to organize manufacturing of RG-35 disconnectors:

- Preliminary technical documentation for tenders to manufacture RG-35 disconnectors. We will prepare the information needed to evaluate manufacturability in line with tender requirements and data sheets (schematic solutions, explanatory note, unit bills of materials).
- Full set of production design documentation for series manufacturing at your facility: assembly drawings, BOMs, purchase parts lists, routing cards, detail and subassembly drawings, assembly and adjustment instructions.
- 3D models and production files: STEP/Parasolid, *.sldprt/*.sldasm (SolidWorks), *.dwg/*.dxf (AutoCAD), *.igs/*.stp for CAM exchange; drawings for laser/plasma cutting and bending; busbar development drawings.
- Electrical part: connection diagrams, parts lists, limit-switch/sensor wiring tables, setting sheets, signal lists for SCADA/DCS.
- If required - adaptation of the design set to your manufacturing capabilities (machine fleet, furnace dimensions, fits and tolerances, coatings) and to the standard range of drives and insulators you use.

Engaging contractors and partners

If you lack your own fabrication or machining, we will arrange cooperation with proven partners: foundry and stamping, galvanizing and electroplating, machining, insulator and busbar manufacturing, assembly shops. For electrical equipment manufacturers and investors we offer a flexible cooperation model: licensed design and process documentation, start-up support, staff training, production audit, step-by-step control of the first series, and certification support. For EPC contractors - typical solutions for integrating RG-35 into substation designs (AIS 35 kV), cable lists, standard drive cubicles and support structures, and turnkey supply with warranty obligations.

Why work with us

- No need to maintain a large team of highly qualified engineers: you receive a documentation set that can be handled by a mid-level engineer.
- Our implementation experience allows launching serial production without pilot units and lengthy on-site refinements.
- Support at all stages: from the technical proposal to stable series output and after-sales service.

For additional information on RG-35 disconnectors contact: inbox@proekt-energo.com

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