When Australian steel producer InfraBuild required additional backup protection for its main electric arc furnace, ABB delivered a solution built for demanding industrial environments. The company selected ABB’s VD4-AF vacuum circuit breaker, featuring a servomotor-driven operating system capable of performing more than five times the operations of conventional breakers. The upgrade was designed to strengthen safety, improve reliability, and reduce long-term operating costs.
Initially, InfraBuild approached the technology with caution. Unlike the plant’s existing spring-operated breakers, the VD4-AF relies on advanced electronic actuation. “The concept sounded impressive, but we wanted reassurance because it involved far more electronics than the older mechanical systems,” said Jorge Aguilar, Electrical Project Engineer at InfraBuild’s Laverton facility in Victoria. ABB addressed these concerns by connecting InfraBuild with other users of the VD4 product family, which has an installed base exceeding two million units worldwide. Positive feedback from these customers gave the project team the confidence to proceed.
InfraBuild ordered two VD4-AF circuit breakers designed specifically for steel furnace applications. The breakers were installed within air-insulated UniGear ZS3.2 switchgear, matching the footprint of the existing equipment. “For this panel, uninterrupted power availability was absolutely critical,” noted Henry Lin, Project Manager, Electrification Service at ABB Australia.
Powered by servomotor actuators, the VD4-AF significantly enhances performance compared to standard designs, while cutting maintenance costs by minimizing downtime for overhauls. Developed for electric arc furnace operations, the breaker supports up to 150,000 mechanical operations without refurbishment and allows quick roll-in, roll-out replacement when servicing is required.
InfraBuild produces steel long products such as reinforcing bar, merchant bar, and rod using recycled scrap metal. The electric arc furnace process, described by Aguilar as “a giant welder generating intense heat,” supports a more sustainable steelmaking model with the potential to operate entirely on renewable energy. At the Laverton melt shop, scrap is melted and transferred for further processing in a cycle that takes around 40 minutes. Power to the furnace must be interrupted before and after each melt, making dependable breaker performance essential. The facility operates continuously for six days a week, placing high demands on equipment reliability.
The circuit breaker replacement marked the final stage of a broader electrical infrastructure upgrade, following transformer enhancements and the commissioning of a new furnace. The previous breaker had reached the end of its serviceable life, with increasing reliability risks and limited access to spare parts. “We reached a point where even our backup breaker couldn’t be replaced if it failed,” Aguilar explained.
Beyond immediate reliability gains, the upgrade offers long-term advantages. Operating since early 2022, the VD4-AF provides a lower-maintenance solution expected to remain in service for decades. Its higher 2,500-amp rating, compared with the earlier 2,000-amp units, also creates scope for future productivity improvements. Increased power capacity could potentially shorten melt cycles, enhancing output without additional infrastructure changes. “Every upgrade at InfraBuild includes an element of future readiness,” said Mr Lin. “This installation allows for higher furnace power if required down the line.”
The installation itself was complex, involving craning a 1.9-tonne panel through the roof and several days of detailed connection work. The effort paid off when the system successfully powered up the furnace. “Seeing the equipment commissioned and performing as intended is always rewarding,” Mr Aguilar said.
The project highlights ABB Electrification Service’s capability to modernize critical assets through advanced retrofit solutions, delivering measurable improvements in efficiency, reliability, and long-term operational resilience for energy-intensive industries.
