Chile Mining Transformers

The mining enterprise required transformers of multiple models, layouts and mounting forms. Detailed customization demands are listed as follows:

Multiple voltage ratios: 13.2/0.4kV,  8.8/0.4kV,  7.2/0.4kV,  4.16/8.8kV,  4.16/0.4kV

Diverse mounting specifications: Ground-mounted, back-pack pole-mounted, crossarm pole-mounted

Wide range of rated capacities: 10kVA, 75kVA, 100kVA, 150kVA, 600kVA, 2000kVA, 2500kVA, 3500kVA

Customized accessory requirements

Anti-pollution bushings suitable for dusty environments

High & low voltage cable boxes for selected units

Over-temperature tripping protection as an option

Customized aperture size and quantity of low-voltage bushings

To address the comprehensive customized requirements including various voltage ratios, mounting methods, capacities and harsh dusty mining conditions, our company adopted a delivery strategy of matrix parameter selection + scene-adaptive structural design + reinforced core components, ensuring each transformer precisely matches mining power supply conditions and on-site construction standards.

1. Demand Analysis & Drawing Confirmation

All detailed technical requirements were repeatedly verified before production. Complete outline and manufacturing drawings were issued and approved by the customer prior to mass production.

2. Scene-Adaptive Structural Design for Different Mounting Types

Customized structural modification solutions were developed for the three mainstream mounting types:

Ground-mounted transformers: Equipped with channel steel base and anchor bolts for fixation. Height-adjustable shock-absorbing pads are fitted on the base to adapt to uneven mine ground surfaces. An emergency oil drain valve is installed at the bottom of the tank to meet fire safety standards. For large-capacity models (≥2000kVA), split radiators are configured for convenient transportation and on-site assembly.

Back-pack pole-mounted transformers: Specially designed for power supply at the end of overhead lines. Compact lightweight tank structure narrows the overall core width, with double-side rear lug plates for hoop connection. Matching hoops are supplied for pole diameters of Φ190mm, Φ230mm, Φ350mm, etc. High and low voltage lines lead out from the side bottom for easy connection with overhead down leads.

Crossarm pole-mounted transformers: Reinforced bottom crossarm brackets with adjustable center distance to fit crossarm combinations of different pole spacing. Double anti-loosening fasteners (lock nuts + cotter pins) are used between the transformer base and brackets to prevent nut loosening caused by long-term wind vibration.

3. Reinforced Protection System for Dusty Mining Environment

Anti-pollution bushings: All high-voltage sides are equipped with anti-fouling silicone rubber composite bushings or long creepage distance porcelain bushings with a creepage distance ≥31mm/kV (based on maximum operating voltage), meeting Class III pollution level and maintaining sufficient insulation flashover distance under dust accumulation.

Sealed tank enclosure: Hermetically sealed tank and cover without conservator to reduce sealing points. Volume change of transformer oil is compensated by corrugated walls, preventing dust from entering the tank through breathers.

Optional cable boxes: IP54 outdoor cable boxes are installed on units with cable box requirements, with sufficient internal wiring space and cable clamping glands to achieve dustproof and waterproof sealing.

4. Over-temperature Tripping Protection & Monitoring System

Dual temperature control protection scheme:

Primary protection: Temperature relays mounted on the low-voltage side (adjustable setting: 80°C alarm / 95°C trip), with temperature probes inserted into temperature measuring tubes on the tank cover.

Optional upgraded protection: Pt100 platinum thermal resistance pre-embedded inside windings, connected to intelligent temperature controllers for real-time winding temperature display via remote DCS and passive tripping contacts for upstream circuit breakers.

Custom low-voltage bushings are manufactured strictly according to customer-specified aperture size and quantity, perfectly matching the customer’s existing low-voltage cable lugs or flexible copper connections without on-site modification.

5. Quality Assurance, Inspection & Delivery

Factory acceptance test: Every unit undergoes full routine tests in accordance with GB/T 6451 and IEC 60076 standards, with bilingual Chinese-English test reports provided.

On-site installation guidance: Illustrated installation manuals and a list of special fastener tools are delivered together with pole-mounted transformers. Free remote video guidance (WeChat / Tencent Meeting) is provided for first-time pole-mounted orders to assist construction teams with lifting, positioning and fastening.

Pre-shipment confirmation: 360° full-view videos of finished transformers with nameplate parameters and remeasured photos of key interface dimensions are sent to the customer for confirmation before shipment to guarantee zero dimensional deviation upon arrival.

Anti-pollution bushings: All high-voltage sides are equipped with anti-fouling silicone rubber composite bushings or long creepage distance porcelain bushings with a creepage distance ≥31mm/kV (based on maximum operating voltage), meeting Class III pollution level and maintaining sufficient insulation flashover distance under dust accumulation.

Sealed tank enclosure: Hermetically sealed tank and cover without conservator to reduce sealing points. Volume change of transformer oil is compensated by corrugated walls, preventing dust from entering the tank through breathers.

Optional cable boxes: IP54 outdoor cable boxes are installed on units with cable box requirements, with sufficient internal wiring space and cable clamping glands to achieve dustproof and waterproof sealing.

Figure 1: Photos of various transformer models

Figure 2: Photos of goods delivery and received by the customer