OSG/LOSG Three Phase Autotransformer

The OSG/LOSG Three Phase Autotransformer (QZB reduced voltage starting autotransformer) is engineered for high efficiency voltage conversion and grid voltage regulation with strong transmission capability. Featuring a common winding autotransformer structure, it delivers lower losses, compact size, and reliable long term operation, while helping suppress interference and reduce inrush current during industrial motor starting. Output voltage is adjustable via multi tap design, making it practical for applications requiring flexible voltage matching and stable power. Typical configurations include a 3~380 VAC input with a 3/N~200–220 VAC output (example model: 50 kVA, Yn0 connection group), but the platform is highly customizable: rated capacity from 50 VA to 2500 kVA, input/output voltage from 1 V to 30,000 V, and frequency 50/60 Hz. Key electrical parameters can be customized, including impedance voltage (1%–20%) and protection grade (IP00/IP20). Standard performance targets can include dielectric withstand strength of 3000 VAC/1 min, insulation resistance ≥500 MΩ, low noise (typically <60 dB(A) at 1 meter), and a robust overload capability (e.g., 2× rated current for 1 minute). Designed for ambient temperatures of 15°C to +40°C and altitude up to 2000 m, it can be supplied with self cooling or air cooling, and insulation class options such as Class F or Class H (temperature rise Class F ≤100K, Class H ≤125K).

Key Features

• High Efficiency & Energy Saving: Common winding design reduces copper and core losses for efficient power transfer.
• Voltage Conversion & Regulation: Ideal for grid voltage regulation, buck/boost conversion, and system voltage matching.
• Reduced Starting Current: Supports reduced voltage motor starting to limit inrush current and protect equipment.
• Flexible Multi Tap Adjustment: Wide adjustable output range for precise voltage setting and application versatility.
• Compact & Lightweight: Space saving open frame structure with convenient terminals for fast installation.
• Anti Interference Performance: Helps suppress interference and improve stability in sensitive electrical environments.
• Customizable Protection & Insulation: IP00/IP20 options and Class F/Class H insulation for different site requirements.
• Reliable Long Life Design: Built for unattended operation with durable structure and strong anti corrosion treatment (process dependent).