This was another installation by us, a 1000 kVA, 11/0.415kV oil-immersed auxiliary transformer labeled AT-1, installed to step down medium voltage (MV) to low voltage (LV) for internal substation utilities and control systems.

Key Features and Components:

• Voltage Rating:
  Primary voltage: 11 kV
  Secondary voltage: 0.415 kV (Low Voltage AC Supply)

• Capacity:
  1000 kVA – suitable for handling significant auxiliary loads such as HVAC systems, lighting, control panels, battery chargers, and switchgear operations.

• Cooling Type:
  ONAN (Oil Natural Air Natural) cooling system, visible through the radiators on both sides that dissipate heat passively.

• Conservator Tank & Breather System:
  Positioned on top to maintain proper oil level and ensure clean air intake via silica gel.

• High Voltage and Low Voltage Bushings:
  Clearly visible at the top (HV side) and at the base (LV side), ensuring safe and efficient electrical connections.

• Protective Systems:
  Includes Buchholz relay, thermometer, oil level indicators, and pressure relief valves for safe and monitored operation.

• Fire Protection Network:
  Encircled by a red sprinkler/fire suppression system for compliance with substation fire safety standards.

Purpose & Application:

This transformer provides essential power to auxiliary systems within the substation—such as lighting, communication, SCADA, and protection systems—ensuring operational continuity, especially during emergencies.

Standards Followed:

Installed and tested in accordance with IEC 60076, IEEE C57, and relevant local utility authority standards for auxiliary transformers.