On-Load Tap-Changer V-VAC
Redefining Tap-Changer Technology
Ensuring reliability •Efficiency
•Maintenance-free performance
On-Load Tap-Changer V-VAC
Why V-VAC Matters
The V-VAC On-Load Tap-Changer integrates a diverter switch and selector within a compact oil compartment, ensuring no switching arcs occur in the transformer’s insulating oil.
This design prevents DGA distortion, enhances safety, and ensures maintenance-free performance for nearly all grid applications – achieving a remarkable maintenance interval of 300,000 operations.
- Benefits of Vacuum Technology
- Technical Highlights
- Applications
- KEY ADVANTAGES
- Support & After Sales
Benefits of Vacuum Technology
No arcing in the tap-changer oil
No oil filtration system required
Reduced maintenance frequency vs conventional oil systems
Compact structure ideal for up to 60-70 MVA / 132 kV applications
Optimized dimensions for space-saving installation
Technical Highlights
Phases: 3
Max rated current: 400 A
Rated short time current: 4 kA / 3 s
Peak withstand current: 10 kA
Step voltage: 1,300 V
Max operating positions: 19 (with change-over selector)
Frequency: 50 / 60 Hz
V-VAC III 400 Y - Neutral point application
V-VAC III 400 D - Any winding point
Applications
Power transformers up to 70 MVA
132 kV grid systems (voltage levels vary by region)
Standard grid and industrial transformer applications
Key Advantages
Arc-free operation ensures clean and reliable DGA results.
The V-VAC OLTC remains maintenance-free for most of the transformer's service life.
Improves overall system reliability and maximizes transformer uptime.
Support & After Sales
Retrofit solutions for existing transformers
Spare parts and replacements available
Thorough in-house testing and validation
Dedicated technical support and after sales-service
Matching Products
Motor Drive Unit
On-Load Tap-Changer V-VAC - frequently asked questions
What is a V-VAC On-Load Tap-Changer for OLTC?
The V-VAC On-Load Tap-Changer is a vacuum switching OLTC designed for voltage regulation in power transformers. It performs tap changes without arcing in tap-changer oil, ensuring stable and clean switching operation.
Why is V-VAC for OLTC considered maintenance-free technology?
 V-VAC for OLTC eliminates arcing inside oil compartments through vacuum interruption. This prevents oil contamination, removes the need for oil filtration systems, and significantly reduces maintenance frequency.
How does V-VAC technology improve OLTC performance and reliability?
 Vacuum switching ensures long-lasting contact performance and consistent tap change operation. This enhances OLTC reliability, minimizes service interventions, and supports uninterrupted transformer voltage control.
What application advantages does the V-VAC On-Load Tap-Changer offer?
 The V-VAC On-Load Tap-Changer features compact and optimized dimensions for space-saving installation. It is ideally suited for transformers up to 60–70 MVA and 132 kV class applications.
When should utilities specify V-VAC for OLTC in transformer procurement?
 V-VAC for OLTC is specified when maintenance-free operation, compact installation, and long-term operational reliability are key procurement requirements for medium-capacity power transformers.
