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33kv Oil Immersed Grounding /Earthing Transformer
Rockwill Electric GROUP Co., Ltd
16yrs 700++ staff 108000m²+m² US$150,000,000+
Rockwill Electric GROUP Co., Ltd
16yrs 700++ staff 108000m²+m² US$150,000,000+
Key attributes
Brand ROCKWILL
Model NO. 33kv Oil Immersed Grounding /Earthing Transformer
Rated voltage 33kV
Phases Three-phase
Frequency range 50/60Hz
Series JDS
Product descriptions from the supplier
Description

Product Overview

Rockwill specializes in the design and manufacturing of 33kV oil immersed grounding transformers, engineered for reliable grounding protection in power systems. Our products comply with IEC and IEEE international standards, ensuring stable and safe operation of electrical networks.

Key Specifications

Product Highlights

Premium Core

The transformer core is made of high-quality cold-rolled oriented silicon steel sheets with 45° full diagonal joints. The iron yoke is securely clamped with through bolts, and the core columns are tied with fiberglass tape. The core surface is coated with silicone resin adhesive for moisture protection and noise reduction.

Superior Winding

The windings are constructed with high-quality copper conductors in a segmented cylindrical structure to enhance interlayer insulation. Vacuum drying technology is applied to ensure excellent electrical performance, high mechanical strength, and minimal partial discharge.

Advanced Insulation and Cooling

The oil immersed grounding transformer features a fully sealed tank with corrugated fins for efficient heat dissipation, eliminating the need for an oil storage tank. Oil tanks are sealed with oil-resistant rubber strips to prevent contact with air, preserving the insulating oil quality and extending transformer lifespan. Compact footprint, aesthetic appearance, and maintenance-free design are key benefits.

Comprehensive Protection Devices

Equipped with pressure relief valves, gas relays, and oil level gauges for real-time monitoring of oil condition. Temperature control devices support remote transmission, allowing convenient supervision of transformer operating temperature.

Technical Parameters

  • Transformer Type: Oil Immersed

  • Connection Groups: ZN (Zigzag)

  • Rated Voltage: Up to 36kV

  • Rated Current: Up to 3000A

  • Short Time Duration: 10s / 30s / 60s or customized

  • Cooling Method: ONAN, ONAF, AN, AF

  • Installation: Indoor / Outdoor

  • Ambient Temperature Range: -40°C to +40°C

  • Standards Compliance: IEC 60076-6, IEC 60076-1, IEEE

  • Enclosure Options: Transformer cabinet with customizable IP ratings, optional CT, VT, and isolation switch

Notes

  • Neutral short time current I0 = IG

  • Neutral zero-sequence impedance Z0 = Phase impedance / 3

  • ±5% off-load tap changer

  • Confirm Z0 value before production if not self-limiting

  • Z0 tolerance ≤ 10%

Rockwill 33kV Oil Immersed Grounding Transformers combine advanced engineering and strict quality control to deliver dependable grounding solutions for power networks worldwide. For inquiries and customization, please contact us.

FAQ
Q: How does the Zig-Zag connection in your 33kV grounding transformer work?
A: The Zig-Zag (ZN) winding provides a low-impedance path for ground fault currents while blocking normal load currents. During a fault, it creates opposing magnetic fluxes to limit current to safe levels (24.8A continuous/800A for 20s) while maintaining system stability and preventing overvoltage damage. Its zero-sequence impedance (Z₀) is precisely controlled within ≤10% tolerance to ensure reliable fault current limitation.
Know your supplier
ROCKWILL
Rockwill Electric GROUP Co., Ltd 16yrs 700++ staff 108000m²+m² US$150,000,000+
Rockwill Electric GROUP Co., Ltd
16yrs 700++ staff 108000m²+m² US$150,000,000+
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On-time delivery rate
Response time
100.0%
≤4h
Company overview
Workplace: 108000m²m² Total staff: 700+ Highest Annual Export(usD): 150,000,000
Workplace: 108000m²m²
Total staff: 700+
Highest Annual Export(usD): 150,000,000
Services
Business Type: Design/Manufacture/Sales
Main Categories: High Voltage Electrical Apparatus
Whole life care manager
Full lifecycle management services for equipment procurement, use, maintenance, and after-sales, ensuring safe operation of electrical equipment, continuous control, and worry-free electricity consumption.
The equipment supplier has passed platform qualification certification and technical evaluation, ensuring compliance, professionalism, and reliability from the source.
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