I. Project Overview: 6kV Explosion-Proof Power Supply Adapted to Underground Coal Mining in Kazakhstan

This complete project consists of 2 sets of KBSGZY-630kVA/6kV and 2 sets of KBSGZY-1600kVA/6kV aluminum-winding flameproof mobile mining substations. Customized for new construction and underground fully-mechanized mining expansion projects in the Karaganda Mining Area of Kazakhstan, the product set provides an all-in-one solution to four core pain points of Central Asian coal mines: extreme low temperature, gas and coal dust hazards, long-distance line voltage drop, and difficult underground transportation.
Hengfengshuai Electric boasts 12 years of experience exporting mining substations to Central Asia. Its products simultaneously comply with IEC60076, GB3836 national standards for mining explosion protection, Kazakhstan GOST explosion-proof access requirements and KZ mine safety regulations. The complete units carry an Ex d I Mb mining flameproof rating, compatible with the local 50Hz 6kV mine power grid, with dual low-voltage outputs of 0.4kV and 0.69kV to supply safe, explosion-proof and stable power to shearers, scraper conveyors, underground pump stations and open-pit mining units.

1. Four Core Power Supply Pain Points of Kazakhstan Mining Areas

a. Extreme winter low temperature down to -40°C: Ordinary mining transformers suffer brittle insulation and heat dissipation failure, leading to frequent shutdowns and production losses. b. Explosive underground environment with methane and coal dust: Non-standard equipment cannot pass explosion-proof acceptance by local mining bureaus. c. Long-distance 6kV transmission lines: Impacts from start-stop cycles of mining equipment cause severe fluctuations in low-voltage levels. d. Conventional copper-winding mining transformers feature excessive dead weight, resulting in high underground rail transportation costs and installation constraints in roadways.

2. General Technical Parameter Table for 6kV Flameproof Mobile Mining Substations

3. Precise Application Scenarios for 6kV Flameproof Mobile Mining Substations

a. KBSGZY-630kVA/6kV: Underground heading roadways, small mining faces, auxiliary ventilation and drainage equipment. b. KBSGZY-1600kVA/6kV: Large fully-mechanized mining faces, long-distance belt conveyors.

II. Advantages of Adopting Hengfeng Electric Custom 6kV Mobile Mining Substation Solution for Kazakhstan

1. Combined Delivery of Two Capacity Models to Reduce Comprehensive Mine Procurement Costs

Traditional mines procure mining transformers of different capacities in separate batches, leading to scattered design, production, customs clearance and land transportation cycles, plus repeated investment in switchgear and roadway civil supporting works. This project delivers 4 units with unified drawings, synchronized production and full-container land transportation directly to Kazakhstan mining areas:

• Combination of high and low capacities covers full mine load demands without separate tenders;

• Fully interchangeable explosion-proof enclosures, protection modules and high/low voltage accessories, cutting spare parts inventory by 50%;

• Mass production lowers unit cost, delivering an 18% reduction in overall investment compared with scattered single-unit procurement.

2. Dyn11 Harmonic Suppression Structure Ensures Stable Operation of Gas Monitoring Equipment

Frequency converters on variable-frequency shearers and belt conveyors in Kazakhstan underground mines generate massive third harmonics, which easily interfere with gas sensors and trigger false safety alarms. The Dyn11 winding structure filters over 70% of harmonic distortion and stabilizes the 0.4kV/0.69kV bus voltage. Its high/low voltage grounding scheme fully complies with Kazakhstan’s 6kV mine power grid standards, greatly improving safety against short-circuit faults and meeting mandatory inspection indicators of local mine safety authorities.

3. Lightweight Aluminum Windings with Low-Temperature Insulation Adapt to Frigid Mining Areas Down to -40°C in Central Asia

The complete unit adopts special low-temperature curing insulation materials for aluminum windings, delivering three core benefits:

• 22% lighter than copper-winding transformers of the same capacity; rail trolleys can transport 2 units in a single trip underground, saving labor and transportation time;

• Insulation remains crack-free and leak-proof at -40°C, eliminating winter shutdowns for heat preservation;

• Passes GOST short-circuit impact tests; windings resist deformation from frequent start-stop cycles of mining equipment, cutting annual underground maintenance frequency by 60%.

4. Thickened Fully-Welded Flameproof Enclosures Provide Dual Resistance to Gas Explosions, Frost and Wind Erosion

The enclosure is integrally welded from high-strength Q345B steel plates with explosion-proof gaps ≤0.2mm, capable of withstanding an internal explosion pressure of 1.5MPa to eliminate risks of gas leakage and secondary ignition. The surface is coated with a double-layer anti-freezing, wind-sand corrosion-resistant coating to prevent enclosure rusting and cracking from winter frost and spring severe wind sand in open-pit mines. All flanges adopt labyrinth sealing structures to block coal dust and underground water from penetrating explosion-proof cavities. The units achieved zero failures in Kazakhstan’s 720-hour low-temperature wind-sand aging test.

5. Integrated Intelligent Comprehensive Protection for Zero-Threshold Commissioning by Local Miners

Both models are equipped with identical intelligent mining protectors integrating 6 layers of protection: overcurrent, short-circuit, earth leakage, overtemperature, gas interlock and phase loss protection. Protection settings pre-calibrated for Kazakhstan’s 6kV power grid at factory allow immediate commissioning upon delivery to mining sites without recalculation and recalibration by professional electrical engineers, drastically shortening power transmission and commissioning cycles and lowering technical barriers for mine operation and maintenance.

6. ±10% Wide Voltage Adaptability Resolves Long-Distance Line Voltage Drop Issues

To address the long 6kV power supply lines and large day-night load fluctuations in Kazakhstan mining areas, optimized electromagnetic magnetic circuit design ensures stable rated low-voltage output under grid voltage fluctuations of ±10%, eliminating under-voltage shutdowns of shearers and open-pit units and supporting 7×24-hour non-stop continuous mining to extend annual mine production hours.

III. Benchmark Project Cases of Coal Mine Projects in Kazakhstan

Case 1: Capacity Expansion Project of Large Underground Fully-Mechanized Coal Mine in Karaganda

6 sets of the same series of aluminum-winding KBSGZY mining transformers were delivered in advance to replace outdated non-standard equipment. Before renovation, over 6 monthly faults including earth leakage and false protection trips occurred, with frequent production halts due to insulation failure in low winter temperatures. Three major improvements were realized after reconstruction:

1. Low-voltage fluctuation controlled within ±3%, harmonic distortion reduced by 72%;

2. Continuous operation for 26 months at -38°C without explosion-proof leakage or insulation damage;

3. Overall mine power supply loss reduced by 15%, earning the supplier the title of Annual Premium Explosion-Proof Equipment Supplier of the local mining group.

Case 2: Power Supply Renovation Project of Pavlodar Open-Pit Coal Mine

The mining area suffers year-round wind sand and minimum winter temperatures of -38°C, with old mining transformers plagued by cracked enclosures and blocked heat dissipation. After deploying the same series of explosion-proof mining transformers under this solution, only one simple inspection of shell dust removal and oil sampling is required annually without frequent production halts for maintenance, making it a standardized renovation demonstration project for open-pit mines in northern Kazakhstan.

Case 3: Supporting Project for Medium & Small Heading Coal Mines in Kostanay

Narrow roadways and high underground gas concentrations make the lightweight aluminum-winding model ideal for transportation in confined roadways. The Dyn11 structure eliminates harmonic interference with gas monitoring equipment, delivering 2 full years of fault-free full-load underground operation. Annual operation and maintenance costs are 36% lower than imported European and American equipment.

IV. Custom R&D and Factory Acceptance Test (FAT) for 6kV Flameproof Mobile Mining Substations for Kazakhstan

1. Special Custom R&D Process

The technical team conducts multiple rounds of electromagnetic simulation targeting Kazakhstan’s operating conditions including -40°C low temperature, gas explosion risks and long-distance voltage drop, widening insulation creepage distances in explosion-proof cavities and optimizing low-temperature heat dissipation oil channels for aluminum windings. Joint reviews by the electromagnetic, explosion-proof and Central Asia project teams confirm explosion-proof structures, land transportation packaging dimensions and GOST certification requirements prior to production launch.

2. Full Set of Factory Testing for 6kV Flameproof Mobile Mining Substations for Kazakhstan

Each unit undergoes routine tests plus special simulation tests replicating Kazakhstan mining area conditions, with bilingual Chinese-Russian test reports issued: a. Routine Test Items: DC resistance, transformation ratio and vector group, power frequency withstand voltage, loss, short-circuit impedance, -40°C low-temperature temperature rise, full-function calibration of comprehensive protection; b. Special Simulation Tests: Underground heat dissipation blockage by coal dust, open-pit wind-sand aging, impact load simulation of mining equipment; c. Type Tests for Prototypes: 720-hour low-temperature wind-sand durability test, enclosure hydraulic explosion resistance test, gas airtight explosion-proof test, sudden short-circuit thermal and dynamic stability test. All units are cleared for land transportation via China-Europe Railway Express only after passing all tests.

V. Cross-Central Asia Land Transportation, Site Acceptance Test (SAT) Delivery and Localized Services

1. Cross-Border Land Transportation Scheme (Direct Delivery to Kazakhstan Mining Areas to Shorten Lead Time)

Units are split into components with anti-rust sealed packaging, and explosion-proof wiring cavities filled with nitrogen for moisture and frost prevention. Combined transportation via China-Europe Railway Express and highways is adopted, with advance handling of GOST explosion-proof import customs clearance and oversized cargo passage permits for mining areas. Full-process temperature and humidity recorders monitor shipments with reinforced anti-collision and anti-freezing protection. The full batch of 4 units is shipped synchronously, with a standard lead time of 45 days for direct delivery to Karaganda Mining Area.

2. Standardized Underground SAT Installation & Commissioning

a. Joint Unboxing Inspection: The owner, Kazakhstan mine supervisors and our Central Asian engineers jointly inspect the integrity of explosion-proof enclosures. b. Reinforcement of Explosion-Proof Seals: Low-temperature resistant sealant is supplemented on all flanges with reliable grounding of underground systems. c. On-Site Retesting of Insulation, Loss and Protection Interlock Functions, issuing test records recognized by local power authorities. d. 24-hour no-load trial operation followed by graded load connection to the 6kV mine power grid for rapid commissioning and production launch.

3. Localized Operation & Maintenance Supporting Services in Kazakhstan

a. Delivery of Russian-English bilingual drawings, FAT reports, GOST explosion-proof certifications and mine-specific operation & maintenance manuals; b. Free offline hands-on training covering underground explosion-proof patrol inspection, low-temperature insulation maintenance and troubleshooting of comprehensive protectors; c. Local spare parts warehouse in Central Asia with delivery of standard accessories to all major mining areas within 7 days to cut downtime for maintenance; d. 24-month full-unit warranty, lifelong remote technical support and on-site service available all year round by resident engineers in Central Asia.

VI. FAQ for 6kV Aluminum-Winding Flameproof Mobile Mining Substations

1. Q: Are aluminum-winding mining transformers suitable for Kazakhstan mining areas compared with copper-winding alternatives? A: Underground roadway transportation conditions in Kazakhstan are limited, and aluminum-winding transformers feature light dead weight to cut transportation costs. Equipped with special low-temperature insulation, they operate stably at -40°C with loss indicators meeting local mine energy consumption standards, delivering lower overall investment for bulk projects.

2. Q: Can 6kV aluminum-winding flameproof mobile mining substations pass Kazakhstan GOST explosion-proof certification? A: Complete GOST and KZ mine explosion-proof qualification documents are delivered with each unit. All test items comply with access audit standards of local mining bureaus and are directly applicable to coal mine project tenders.

3. Q: What is the delivery cycle for a single batch of 4 complete sets of 6kV flameproof mobile mining substations? A: Standard production cycle takes 30 days, with land transportation via China-Europe Railway Express ranging from 12 to 18 days, totaling approximately 45 days for direct delivery to Kazakhstan mining areas. Production schedules can be adjusted to align with mine construction timelines.

4. Q: Can the units adapt to supporting power supply of mine photovoltaic green power systems? A: The Dyn11 harmonic suppression structure accommodates non-linear loads of photovoltaic inverters, and the wide voltage tolerance copes with day-night fluctuations in photovoltaic output. The products are widely deployed for photovoltaic supporting projects of open-pit mines in Kazakhstan.

VII. Solution Summary & Cooperation Inquiry

This complete solution of 4 KBSGZY aluminum-winding flameproof mobile mining substations fully covers power supply demands for underground heading and large fully-mechanized mining scenarios in Kazakhstan. Supported by four core designs including -40°C low-temperature explosion-proof enclosures, lightweight aluminum windings, integrated intelligent protection and Dyn11 harmonic control, it delivers an all-in-one solution to industry pain points of Central Asian coal mines including extreme cold, gas explosion risks, transportation difficulties and voltage fluctuations.
Hengfengshuai Electric is fully familiar with complete GOST and KZ mine access standards of Kazakhstan, capable of customizing full-capacity KBSGZY flameproof mobile mining substations of 6kV/10kV classes for new construction and expansion general contracting coal mine projects across all Central Asian countries. Mining EPC contractors, local Kazakhstan mining groups and foreign trade suppliers are welcome to request detailed quotations and full sets of qualification documents. Contact Email: hfs@hengfengshuai.com