RLND-10 and RLNDZ-10 disconnectors are intended for making and breaking de-energized sections of medium-voltage circuits that are live (no load switching), as well as for earthing isolated sections by means of fixed earthing switches.
RLND-10 disconnectors are supplied as standard in a three-pole configuration. The main blades open in the horizontal plane (side-break). The equipment is designed for outdoor service in accordance with EN/IEC 60721-3-4; ambient temperature from +40 °C down to -60 °C; wind speed with icing up to 15 m/s; wind speed without icing up to 40 m/s; installation altitude up to 1000 m a.s.l.; ice thickness up to 10 mm.

Technical data

Application and scope

RLND (RLNDZ) are outdoor, two-post line disconnect switches for distribution networks rated 6–10 kV (50 Hz). The devices provide a visible isolating gap and ensure safe work on de-energized sections of overhead and cable lines, busbars, jumpers, taps, feeders of distribution points, and outdoor switchyards of package transformer substations. They are used:

• as line switches on 6–10 kV overhead lines - for operational reconfiguration, sectionalizing, and back-up;
• in outdoor switchyards - as bus and feeder disconnectors with/without earthing blades;
• to isolate for maintenance load break switches, reclosers, current/voltage transformers, and surge arresters;
• for process isolation of inlets to KTP, RP, KRU/KRUN and to meet “visible break” requirements;
• for operational earthing of de-energized sections via integrated earthing switches (RLNDZ versions).

Disconnectors are intended for off-load switching (in the absence of load current). Depending on the scheme and conditions, switching of small magnetizing inrush currents of unloaded transformers and charging currents of line sections is permissible within limits defined by the project and applicable standards. A clearly visible isolating gap, unambiguous position indication, and the possibility of interlocks make RLND/RLNDZ a basic element for safe operation of distribution networks.

Service conditions

Designed for outdoor operation per EN/IEC 60721-3-4 (stationary, non-weatherprotected locations). Operating temperature range -60 °C … +40 °C. Acceptable wind speeds: up to 40 m/s (no icing) and up to 15 m/s (with icing); ice thickness up to 10 mm; installation altitude up to 1000 m a.s.l. Components exposed to corrosion and icing have protective coatings and shapes that promote self-cleaning by wind and gravity. Live parts are dimensioned for atmospheric influences, humidity and pollution, with creepage distances and clearances meeting insulation categories I/II.

Insulating parts - porcelain or polymer line post insulators with enhanced resistance to UV, tracking and erosion. Mechanical assemblies are rated for repeated open–close cycles at sub-zero temperatures without degradation of contact pressure. For areas with extreme wind/icing loads, reinforced supports and enlarged bases are available.

Design and construction

The double-post arrangement comprises two bearing columns with support insulators linked by a galvanized steel base. One column carries the fixed contact assembly; the other carries the moving blade rotating in the horizontal plane (side-break). Opening/closing is via an operating shaft and linkage system that ensures synchronized blade rotation with a defined angle (typically 90°). RLNDZ versions add an earthing blade on the common frame with its own shaft and mechanical interlock.

• Current path. Copper or aluminium conductors with bimetallic transition pads at terminals. Contact surfaces are silver-plated to reduce contact resistance and improve corrosion resistance. Spring-loaded contact assemblies provide automatic wear compensation, stabilizing contact pressure over life.
• Frame and supports. Structural steel with hot-dip galvanizing for long-term corrosion protection. Fastening points use high-strength bolts with self-locking nuts.
• Bearings. Rotating units on sealed bearings protected from dust and moisture. Depending on version, PTFE/bronze-graphite bushings may be used.
• Arcing horns and surge arresters. On request, arcing horns and mounting pads for surge arresters can be fitted for local overvoltage limitation.
• Operating mechanism. Manual lever operator with defined positions; optional motor operator (electric drive) for remote control, with limit switches and mechanical position indicators.
• Installation. Suitable for mounting on concrete/steel poles, cross-arms and outdoor substation steelwork. Geometry allows “left” or “right” orientation relative to the operating axis, and blade orientation toward the line or busbars.

Creepage distances and clearances are selected for 6–10 kV service, ensuring a visible break for work permits. Flat or branching clamps are used for bus/conductor connections, accommodating aluminium/copper with bimetallic washers.

Safety and interlocking

Personnel safety is ensured by the visible isolating gap, mechanical interlocks, and the possibility to fit locking devices. The design provides:

• mechanical interlock between the main circuit and earthing switch (it is impossible to close the earthing blade when the main circuit is closed, and vice versa);
• provisions for padlocks on operating mechanisms and linkages to exclude erroneous operations;
• clear “ON/OFF/EARTHED” indication on the operator; option to install limit switches for status indication and remote control schemes;
• travel stops and adjustable end-stops preventing incomplete closing and vibration-induced movement;
• protective shields on contact assemblies (on request) to reduce risks of accidental contact and the influence of birds/small animals.

The operating documentation includes work-permit guidance, interlock checks, and maintenance intervals. When a motor operator is used, electrical interlocking is implemented in coordination with mechanical interlocks.

Versions and options

Base versions:

• RLND-10/200, /400, /630 - without earthing switch; three-pole;
• RLNDZ-10/200, /400, /630 - with fixed earthing switch; three-pole.

Available options:

• manual or motor operator with remote control (dry contacts, position signalling);
• left/right arrangement, mirror blade orientation;
• terminal variants (flat busbars, cable lugs, clamps for ACSR, etc.);
• enhanced anti-corrosion package (hot-dip galvanizing + paint coating);
• polymer or porcelain insulators depending on pollution/icing requirements;
• complete with limit switches, mechanical indicators, pads for surge arresters, and position sensors.

Supply scope (typical)

Options and accessories

Compliance with standards

Design, manufacturing and testing comply with applicable standards for this class of equipment, including:

• IEC 62271-102:2018/A1:2022 - “High-voltage switchgear and controlgear - Part 102: Alternating current disconnectors and earthing switches”;
• IEC 62271-1 - “High-voltage switchgear and controlgear - Part 1: Common specifications” (relevant clauses);
• EN/IEC 60721-3-4 - “Classification of environmental conditions - Part 3-4: Stationary use at non-weatherprotected locations (outdoor)”;
• IEC 60815-1 - “Selection and dimensioning of high-voltage insulators for polluted conditions” (creepage distance guidance);
• DSTU EN 62271-102:2016 - national adoption of IEC requirements for Ukraine.

We offer documentation for manufacturing RLND-10 and RLNDZ-10 disconnectors:

– Preliminary technical documentation for tenders to manufacture RLND-10 and RLNDZ-10. We will prepare the information needed to assess feasibility in line with tender requirements and data sheets.
– Detail drawings, 3-D models and other documentation to manufacture RLND-10/RLNDZ-10 at your facility. If in-house fabrication of parts is not planned, we will help outsource them. Final assembly and mounting will be performed at your site.
– All documentation can be adapted to project requirements and to your plant’s manufacturing capabilities.
– If other manufacturers’ equipment is installed at the substation, we will prepare documentation to manufacture matching equipment as an addition to the installed base.

Benefits of working with us:

– No need to maintain a large team of highly qualified engineers - you receive a complete documentation set that can be handled by a mid-level engineer.
– No need to build pilot prototypes - our experience allows immediate start of serial production.
– Working to our documentation, your specialists will receive consulting on all nuances of manufacturing RLND-10/RLNDZ-10.

Engaging contractors and production partners

We build cooperation with steelwork, galvanizing, machining and die-casting plants to launch serial batches of RLND/RLNDZ. Where needed we involve insulator manufacturers (porcelain/polymer), suppliers of bimetallic pads and high-strength fasteners. For investors we offer standard techno-economic models, loading plans and starter permitting packages for organizing an assembly line/workshop. We conduct production ramp-up, manufacturability audits and personnel training.

For additional information on RLND-10/RLNDZ-10 disconnectors please contact: inbox@proekt-energo.com

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