Description of Aux Transformer

An Auxiliary Transformer (Aux Transformer) is a specialized low-to-medium voltage transformer designed to supply reliable power to auxiliary systems in industrial facilities, power plants, substations, and large commercial complexes. Its core function is to step down high-voltage electricity (typically 10kV–35kV) from the main grid or generator to low-voltage levels (380V/220V) suitable for auxiliary equipment, such as pumps, fans, lighting, control systems, and communication devices. These auxiliary systems, though not directly involved in primary power generation or transmission, are critical for maintaining the overall operational efficiency, safety, and stability of the facility.

In normal condition the standing by transformer stays in hot condition, i.e. high voltage side is charged. Once any problem happens to the main transformer, the standing by transformer will be put in operation, which is for internal use only.

Features of Aux Transformer

• Reliability-Focused Design: Built to ensure continuous operation, with many configurations including backup units to prevent downtime caused by primary transformer failures. This redundancy is vital for facilities where auxiliary power loss could disrupt critical processes.

• Wide Voltage Adaptability: Primary side voltage matches the facility’s main power source (e.g., 10kV grid), while secondary side outputs standard low voltages (380V three-phase for machinery, 220V single-phase for lighting/controls) to align with auxiliary equipment requirements.

• Compact and Space-Efficient: Compared to main transformers, Aux Transformers have smaller capacities (typically 50kVA–2000kVA) and a compact structure, making them suitable for installation in confined spaces like switchgear rooms or auxiliary power rooms.

• Enhanced Protection Mechanisms: Equipped with built-in safeguards such as overcurrent protection, short-circuit protection, and temperature monitoring to protect both the transformer and connected auxiliary loads.

• Durability in Diverse Environments: Designed to withstand industrial conditions, including dust, vibration, and moderate temperature fluctuations. Oil-immersed variants resist moisture, while dry-type models (epoxy-cast) are ideal for indoor, low-maintenance settings.

• Efficiency for Low-Load Operations: Optimized for partial or varying loads (common in auxiliary systems) with low no-load losses, ensuring energy efficiency even when power demand is not at peak levels.