In typical industrial mining areas in South Africa, the power distribution system is a core safeguard for production continuity and operational safety. However, under complex operating conditions such as high dust levels, large temperature differentials, and strong impact loads, traditional distribution solutions often struggle to meet the requirements for long-term stable operation.
This project addresses the distribution system upgrade and renovation of a core mining area in South Africa. It adopts KYN28 indoor metal-clad withdrawable switchgear, systematically resolving the user's long-standing issues of low insulation reliability, high equipment wear, and insufficient maintenance efficiency. This solution not only completes equipment renewal but also forms a systematic distribution solution suitable for extreme operating conditions.
I. User Operating Conditions and Main Challenges
Before project initiation, the mine's O&M team mainly faced the following three categories of issues, which directly affected production efficiency and operational safety:
- Insulation risks caused by environmental factors: The mining site has abundant dust and large day-night temperature differentials, making condensation likely. The original equipment had a relatively low protection rating. Dust accumulation shortened creepage distances, easily causing pollution flashover and resulting in unplanned outages.
- Equipment stress caused by impact loads: The startup currents of large crushers, conveyor belts, hoists, and other equipment are high, with significant harmonic content. Such impact loads impose higher requirements on the mechanical life of circuit breakers and the dynamic and thermal stability of the cabinets.
- Insufficient maintenance efficiency affecting production continuity: The original fixed-type switchgear required relatively long outages during maintenance, and the interlocking functions were not sufficiently comprehensive, resulting in higher operational risks. For a mining production system operating continuously 24 hours a day, outage time directly affects output.
Figure 1: KYN28 switchgear array, providing stable support for the mine's power distribution system.
II. Solution Selection: Why Choose KYN28 Metal-Clad Switchgear
During the selection stage, the project team conducted a comparative analysis between fixed-type ring main units and KYN28 metal-clad withdrawable switchgear.
Although the fixed-type solution had a lower initial procurement cost, its disadvantages were relatively obvious under the operating conditions of high dust, strong impact, and continuous production in South African mining areas.
Ultimately, KYN28 switchgear was adopted due to its relatively good interchangeability, safety, and maintenance convenience.
| Comparison Dimension |
Traditional Fixed-Type / Ring Main Unit Solution |
KYN28 Metal-Clad Withdrawable Solution (Adopted in This Project) |
Main Advantages |
| Maintenance efficiency |
Circuit breakers are fixed-installed; fault handling requires relatively long outages |
Withdrawable carriage structure; core modules can be fully withdrawn, supporting rapid replacement with spare carriages |
Shortens outage time, suitable for continuous production scenarios |
| Safety protection |
Relatively simple compartment separation; higher risk of arc fault propagation |
Metal-clad separation; busbar compartment, circuit breaker compartment, cable compartment, and instrument compartment are mutually independent |
Reduces risk of fault propagation, enhances personnel and equipment safety |
| Expansion capability |
Expansion and modification are relatively difficult, requiring rewiring |
Standardized interfaces; relatively good carriage interchangeability |
Facilitates subsequent capacity expansion of the mining area |
III. Technical Configuration and Construction Workmanship
For the special operating conditions of mining areas, this project has carried out targeted optimization in technical configuration and construction phases. The design and construction are implemented with reference to relevant standards including IEC 62271-200
1.Cabinet Protection and Compartment Separation
The KYN28 cabinet is assembled from aluminum-zinc coated steel sheets processed by CNC, offering relatively good corrosion resistance. The enclosure protection rating is IP4X, and IP2X when compartments are open.
The cabinet adopts metal-clad separation and is equipped with a comprehensive interlocking mechanism, including functions to prevent incorrect opening/closing of circuit breakers, prevent pulling and closing of disconnectors under load, prevent closing of earthing switches while energized, prevent closing while earthing lines are connected.
And prevent accidental entry into energized compartments, thereby reducing dust ingress and misoperation risks.
2.Circuit Breaker Configuration and Impact Resistance
For impact loads, this project selected high-performance vacuum circuit breakers with a rated current of 1250 A and a rated short-circuit breaking current of 31.5 kA, featuring relatively high mechanical life and electrical life, capable of adapting to current impacts caused by frequent start-stop operation of mining equipment.
Figure 2: Clear internal cabinet structure, standardized secondary wiring, and circuit breakers with relatively strong impact load resistance.
3.Cable Termination Construction Workmanship
In cable compartment construction, the following aspects were emphasized:
- Phase sequence identification: Strict identification treatment according to yellow, green, and red three-phase color markings (as shown in the figure), ensuring accurate O&M identification and reducing misoperation risks.
- Earthing connection: Reliable earthing using copper braided straps, ensuring timely discharge of fault currents and safeguarding equipment safety.
- Electric field control: Stress control treatment for high-voltage cable terminations, improving electric field distribution and reducing partial discharge risks.
Figure 3: Standardized cable termination fabrication and reliable earthing connection, providing assurance for insulation safety.
4.Protection and Control Functions
This project is equipped with high-performance digital feeder protection relays supporting the IEC 61850 communication standard, capable of recording fault waveforms and sequence of events. After tripping, O&M personnel can quickly determine fault types such as overcurrent, instantaneous overcurrent, and earth faults through the protection devices, improving fault location and handling efficiency.
Figure 4: Protection relays used to record power grid operating status, providing data support for fault analysis.
5.Environmental Adaptability Design
In response to the characteristics of high altitude and large temperature differentials in South African mining areas, this project carried out targeted optimization:
- High-altitude adaptation: For mining areas with altitudes exceeding 1000 m, enhanced insulation or high-altitude type products are selected to compensate for the impact of reduced air dielectric strength on insulation levels.
- Anti-condensation measures: Temperature and humidity controllers and heaters are installed inside the cabinet to automatically regulate internal humidity according to environmental changes, reducing the risk of moisture affecting insulation components.
IV. Total Cost of Ownership (TCO) Analysis
For mining enterprise users, equipment selection requires not only consideration of initial procurement costs but also comprehensive evaluation of operation and maintenance, downtime losses, spare parts management, and service life throughout the full lifecycle.
After project commissioning, equipment operating stability improved significantly, the number of unplanned outages decreased, O&M efficiency improved, and overall operating results met the expected objectives.
V. After-Sales Service
To ensure long-term stable operation of the equipment, we provide the following after-sales service commitments:
- Warranty: 24 months of free warranty from the date of acceptance.
- Response: 2-hour remote response; on-site arrival within 24 hours in western South Africa and within 48 hours in eastern South Africa.
- Inspection: During the warranty period, 2 free on-site inspections per year, with equipment health assessment reports issued.
- Spare parts: Continuous supply of key spare parts for 10 years after product discontinuation.
- Training: No fewer than 8 hours of specialized training provided at equipment delivery.
VI. Conclusion
This distribution upgrade project in a South African mining area demonstrates that the KYN28 metal-clad switchgear solution has relatively good applicability under operating conditions such as high dust and high impact loads. While improving power supply reliability, this solution also reserves space for subsequent capacity expansion of the mining area.
This solution is suitable for industrial power distribution scenarios such as mining, cement, metallurgy, and chemicals that involve high dust, strong impact loads, or continuous production requirements.
If your project faces similar distribution issues, you are welcome to contact our engineers for selection consultation and solution evaluation.
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