VUBB Compact On-Load Tap-Changer

As grids become more dynamic and energy demands become more distributed, the role of On-Load Tap-Changers (OLTCs) has expanded — even into compact transformer applications that demand high performance in smaller footprints.

The VUBB Compact, part of Hitachi Energy’s proven T-Sync® OLTC family, is a new-generation tap-changer engineered to meet this need. It brings the reliability and rugged design of the widely trusted VUBB platform into a smaller, smarter, and more space-conscious solution — ideal for transformer OEMs and end-users navigating modern design constraints without compromising on operational excellence.

Key Benefits

Optimized for compact transformer integration The VUBB Compact’s reengineered architecture enables seamless installation into transformers with smaller tanks and tighter layout requirements, addressing one of the most pressing challenges in modern transformer design.

High performance in a smaller footprint Despite its reduced size, the VUBB Compact maintains the mechanical integrity, proven switching performance, and robust electrical endurance of the original VUBB — making it ideal for demanding utility, industrial, and renewable applications.

Multiple variants for voltage flexibility Offered in four tailored variants, the VUBB Compact supports different voltage classes and application profiles. This flexibility allows OEMs to select the best-fit OLTC design for each transformer — reducing design compromises and enabling precision engineering.

Ease of integration and operation Designed for simplicity in both manufacturing and field service, the VUBB Compact features standardized interfaces, reduced oil volumes, and an intuitive operating mechanism — supporting streamlined transformer production and reliable operation. Hitachi Energy also takes pride in training and certifying end-users of its tap-changers, so they can perform inspection and service independently, on their own, without involving Hitachi Energy.

Sustainable, future-ready design With a reduced material footprint and improved efficiency, the VUBB Compact supports the sustainability goals of transformer OEMs and grid operators alike. Its design is optimized for long life cycle operation and minimal environmental impact.

Applications

Distribution and power transformers with space constraints
Renewable integration transformers
Urban and indoor substations
Mobile transformers and skid-mounted solutions

Part of the T-Sync™ OLTC Family

The VUBB Compact is the latest addition to Hitachi Energy’s T-Sync™ portfolio — a family of advanced On-Load Tap-Changers engineered for synchronized reliability, operational efficiency, and long-term performance.

Optimize your transformer and its performance — even in the tightest spaces.

Explore how the VUBB Compact gives you the freedom to design smarter, more efficient transformers without compromise.

Key Benefits

Applications

Part of the T-Sync™ OLTC Family

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