Product Overview

Rockwill’s 35kV oil-immersed earthing transformer is specially engineered to provide a reliable neutral grounding point in medium-voltage networks where direct grounding is not available. Designed with a zig-zag winding configuration, this 3-phase transformer ensures optimal zero-sequence impedance, effectively limiting ground fault currents and stabilizing transient overvoltages.

Its robust oil-immersed construction guarantees long-term insulation reliability and thermal performance in outdoor environments.

Key Features

• Zig-Zag Winding: Enables controlled neutral grounding and effective zero-sequence current flow for protective device coordination.

• High Insulation Performance: Complies with 35kV-class insulation levels and withstand voltage standards.

• Efficient Core Design: Made of cold-rolled grain-oriented silicon steel to reduce core losses and no-load current.

• Copper Windings: Oxygen-free copper ensures reduced winding losses and superior short-circuit resistance.

• Fully Sealed Tank: Maintenance-free with anti-corrosion surface and integrated oil conservator (if required).

• Standardized Manufacturing: Built in accordance with IEC 60076, IEEE, and customer-specific utility codes.

Typical Applications

• Medium-voltage distribution systems (33/35kV class)

• Renewable energy substations (solar, wind)

• Isolated generator grounding systems

• Utility and industrial MV feeders requiring neutral grounding

• Protection system grounding via NGR (Neutral Grounding Resistor)

Technical Highlights