100kVA 20kV Oil-immersed Distribution Transformer S(B)13-NX3 Energy Efficiency Level 3

Detailed Model Code Explanation

• "S(B)": This code is a standard designation for three-phase oil-immersed distribution transformers in the power industry. The letter "S" specifically denotes a three-phase structure, which matches the three-phase alternating current (AC) power supply system widely used in residential, industrial, and commercial scenarios. The parentheses-enclosed "B" indicates that the low-voltage side adopts a foil winding (instead of traditional round or rectangular wire windings). Foil windings have a larger cross-sectional area and tighter winding density, which reduces current density, lowers copper loss, and ultimately enhances current-carrying capacity—a key advantage for handling sudden load increases.                                           
• "13": As a classic design serial number for oil-immersed transformers, "13" represents a technically mature and stable product platform. This design has undergone decades of market iteration, with optimized iron core lamination processes (to reduce no-load loss) and reinforced tank structures (to improve pressure resistance). Its long-term operation data shows low failure rates (typically below 0.5% per year) and predictable maintenance needs, making it a reliable option for long-term power distribution projects.                                                                                 
• "NX3": This suffix is tailored for basic power distribution scenarios. It supports standard voltage ratios (e.g., 10kV/0.4kV, the most common ratio for low-voltage distribution) and is compatible with conventional auxiliary components (such as on-load tap changers for voltage regulation). Its simplified internal wiring and standardized interface design also reduce the complexity of on-site installation and commissioning, shortening the project’s construction cycle.                                                                                                                                                               
• "Energy Efficiency Class 3": This is the entry-level energy efficiency rating for oil-immersed distribution transformers, meeting the minimum energy efficiency requirements specified in national standards (e.g., GB 20052-2020 in China). Under typical operating conditions (load rate of 40%-60%, the average load level for most basic distribution networks), its energy efficiency is balanced—while it cannot match the low loss of Class 1 or 2 models, it fully satisfies the needs of regular power distribution (such as supplying electricity to small residential areas or low-load industrial workshops) where energy efficiency is not the top priority.

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Company Profile

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Guanggao Transformer is a professional transformer manufacturer. We produce single-phase, three-phase, dry-type, distribution, and high-voltage transformers (110 kV and above). We meet IEEE/ANSI/UL/CSA and IEC standards. Guanggao Transformer has nearly 25 years of transformer export experience. The company has modern laboratory construction, such as high-voltage test hall, within which there is a 3000kV lightning impulse testing device, and some advanced testing equipment, such as CA-21 moisture analyzer from Mitsubishi, American Fluke Ti30 infrared image detector, American RM-3WE three dimensional vibration. And it was identified as the national power transformer energy efficiency testing laboratories in 2011.

The company has undertaken the National Olympic Security Power Project, the National 851 project, the whole construction of the Guangzhou Asian Games, Guangzhou BRT and other important security power projects. The products used in the above projects are highly safe and in a reliable operation throughout the country. Also, these products are exported to Myanmar, Madagascar, Malaysia,other countries. Enjoying a good reputation on the electromechanical market, "Guanggao Brand"was identified as Guangdong famous brand, the product was identified as the National Energy Efficiency Star Products and Brand-Name Products in Guangdong Province.If you have transformer needs, please contact us.

Contact us

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•    Add: No. 15, Yunpu 1st Road, Yunpu Industrial Zone, Huangpu, Guangzhou, Guangdong, China
•    Tel: (+86)-020-82505003
•    Email: ggelectric@gz-gg.com