The YAKNO-10 (PKKZ-10) standalone outdoor mining switchgear cubicle is a ready-to-deploy solution for receiving and distributing three-phase 50 Hz electrical power at 6/10 kV in open-pit mines and concentrator plants. It is intended for connection to 6/10 kV overhead lines and operation in main and branch feeders of pit infrastructure. Structurally, it is a splash-proof metal cubicle (IP34) with double-sided access, partitioned into independent compartments for the disconnector, medium-voltage circuit breaker, voltage transformer and control, featuring a comprehensive system of mechanical interlocks and a convenient serviceable relay panel for commissioning and maintenance.

Purpose and applications

YAKNO (PKKZ-10) supplies excavator fleets, drilling and pumping units, crushing and screening complexes, conveyor lines, and connection nodes of in-pit transmission lines. The cubicle switches and protects outgoing feeders to rotating machines (motors), power transformers and auxiliary distribution boards, supporting both local and remote control of feeder apparatus. Typical schemes such as “overhead line - cable feeder,” “cable - cable,” as well as sectioning of overhead lines with single- or double-ended supply enable flexible adaptation to pit network topology and project development stages.

The solution is designed for use within the distribution systems of power plants and industrial substations in the mining and metals sector, at connection points for mission-critical agricultural and industrial consumers, and as part of temporary/mobile power packages where rapid installation, redeployment and reliable medium-voltage switching are required.

Technical data

Service conditions

The cubicle is intended for outdoor operation per EN/IEC 60721-3-4, in ambient temperatures from -45…-40 °C up to +50 °C, at installation altitude up to 1000 m above sea level, under mechanical stresses typical for open-pit sites, in a non-hazardous, non-aggressive atmosphere with controlled dust levels. The enclosure protection class is IP34 to IEC 60529, confirming splash-proof robustness suitable for open pit areas.

Space heaters are provided in the relay compartment and breaker operating mechanism; for low-temperature service, automatic anti-condensation heating can be enabled to maintain a set temperature, reducing moisture risk and ensuring consistent switching at sub-zero conditions. For installation above 1000 m, apply altitude correction factors to insulation and test levels per insulation-coordination practice (IEC 60071-1).

Layout and construction

The YAKNO (PKKZ-10) enclosure is a heavy-duty, fully welded steel housing with anti-corrosion coating. The interior is partitioned by solid barriers into functional compartments to localize faults and raise personnel safety. Each compartment has a dedicated door with latching hardware and mechanical interlocks. A perforated viewing screen provides visual indication of disconnector blade position; doors have opening limiters and are secured in a safe position during service.

The disconnector compartment includes a line disconnector with earthing blades, through-type insulators, and metal-oxide surge arresters (MOV) for lightning and switching-surge protection. A positive mechanical interlock couples the main and earthing shafts to prevent mal-operation during switching. The breaker compartment is equipped with a vacuum circuit breaker from leading manufacturers, current transformers (including a zero-sequence/core-balance CT), a three-phase voltage transformer (VT/PT), interlocking devices, and surge arresters to protect outgoing feeders. The control compartment contains disconnector drives, a removable/swiveling relay panel with protection-and-control (PAC), metering and indication, plus lighting and a service outlet.

For overhead-line entry, line-post insulators and an intake crossarm are used; for cable feeders, a sealed cable termination with optional side entry and provision for clamping two cables (as per execution). The zero-sequence CT design allows repositioning near the cable entry; optional skid rails enable a mobile/skid-mounted variant for quick relocation within the pit. All live bus parts are copper with a minimized number of bolted joints and plated contact surfaces to reduce contact resistance and operating losses.

For seamless project integration, removable elements (crossarm, insulators, skids) are provided for transport, with full device and wire marking, a single-line diagram on the inside of the control-door, and dedicated pads/bolts for connection to the site earthing grid. Sealing of revenue-metering circuits and a packing list are supplied in the O&M package.

Safety and interlocking

Personnel safety is ensured by a multi-layer concept: segregated compartments; inter-device mechanical interlocks (disconnector/earthing/breaker/doors); protective screens preventing access to live parts; and work practices for switching and application of portable earthing per recognized procedures. Interlocks enforce the prescribed sequence of operations; operating forces are limited and access to MV compartments is blocked when apparatus is energized.

Executions and options

Available executions include: overhead or cable entry, cable or overhead exit; line sectioning (single- or double-ended supply); cubicles with a power transformer up to 40…63 kVA and LV outgoing feeders; combined solutions with rotating-machine protection. Vacuum circuit breakers are standard; oil/SF₆ breakers can be supplied to project specification. Options include additional earthing blades on the outgoing line, surge arresters, space heaters, temperature sensors, active/reactive energy metering, remote control and diagnostics.

Typical configurations

• Overhead-line entry - cable feeder exit (motor, transformer and 6/10 kV switchboard section feeders).
• Cable - cable (nodes linking main and branch cable lines; rotating-machine protection).
• Overhead - overhead for line sectioning with single- or double-ended supply.
• Cable entry - overhead exit (feeders to mobile consumers).
• Overhead-line entry with power transformer up to 40…63 kVA and LV outgoing feeders (local auxiliary supply).

Standards compliance

Design and manufacture consider applicable test and acceptance rules and the following standards:

1. IEC 60529: Degrees of protection provided by enclosures - IP Code (cubicle rating: IP34, splash-proof).
2. EN/IEC 60721-3-4: Classification of environmental conditions - stationary use at non-weatherprotected locations (outdoor; replaces GOST 15150 U1).
3. IEC 62271-200: A.C. metal-enclosed switchgear and controlgear for 1…52 kV - general requirements and type tests.
4. IEC 62271-1 and IEC/EN 60071-1: Common requirements and insulation coordination - rated insulation levels and test duties.
5. IEC 61936-1 and EN 50522: Power installations exceeding 1 kV AC and earthing of power installations (for installation and earthing practices).

Partnering with contractors and OEMs

We welcome cooperation with electrical installation contractors, component manufacturers (circuit breakers, CTs/VTs, surge arresters, drives, PAC), and investors planning localized production of YAKNO (PKKZ-10) cubicles using our documentation. Localization of selected modules, end-to-end quality procedures and certification support are available, including alignment with IEC 62271-200 for export projects.

Documentation and engineering support

We provide preliminary tender documentation, detail drawings, 3D models (AutoCAD, SolidWorks), DXF/DWG/Parasolid formats, main and auxiliary wiring diagrams, data sheets, specifications, spare-parts lists and lists of removable elements. Documentation can be adapted to project requirements and customer manufacturing capabilities (fixed installation or skid-mounted execution). For existing substations with third-party equipment, we prepare compatible solutions and transition parts, including relay panels and cable terminations.

Protection, control and metering

PAC is tailored to the feeder function. For “motor” loads: instantaneous overcurrent, overload protection, earth-fault protection and undervoltage. For “transformer” loads: instantaneous and time-overcurrent, earth-fault protection and overload. Included are measurements (voltmeter, ammeter), active-energy metering (and reactive on request), heater control for relay compartments, and inputs for external trip commands. The relay panel is removable/swiveling for ease of service.

Why work with us

- Reduced engineering burden: a complete documentation set enables assembly and commissioning by mid-level engineers with our process support.
- Fast series launch: we factor in routine and type test requirements, allowing batch production without lengthy pilot prototypes.
- Medium-voltage switchgear expertise: we select apparatus (VCB, CT/VT, surge arresters, drives), configure PAC to feeder type, and ensure alignment with IEC 62271-200 for export markets.

For additional information on YAKNO please contact: inbox@proekt-energo.com

As is well known, an error made at the design stage costs tenfold in manufacturing and a hundredfold in operation. Compliance with IEC/EN requirements, correct apparatus selection and PAC settings are investments in reliability and safety.

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