Hyosung Heavy Industries Develops Korea’s First Gas-Insulated Circuit Breaker for Export to the US

Hyosung Heavy Industries has successfully developed a gas-insulated circuit breaker for export to the US using a spring-operated mechanism.

The company said on March 20 that it has completed the development of a 362 kV GCB (Gas Circuit Breaker) using a spring operation method and passed certification testing under IEEE standards. GCB is a key safety device that ensures the stable operation of power grids by managing electrical loads and quickly interrupting current during abnormalities to prevent power outages or equipment damage.

Hyosung Heavy Industries became the first Korean power equipment company to apply a spring-operated mechanism to its newly developed 362 kV GCB. This equipment significantly reduced noise and improved quality and reliability as it operates with only about one-fifth of the energy compared with conventional pneumatic operation methods. In addition, the need for the on-site assembly of components is eliminated and the installation time is reduced by over 80% since it is designed for transport as a fully assembled unit.

In particular, the product already secured pre-orders worth more than KRW 100 billion from US customers from its development stage. This is the result of reflecting the feedback from local customers on reducing operating noise and shortening the installation time. This circuit breaker is an essential component used in US substations, and demand is expected to increase further in the US market as investment in power grids expands, driven in part by the construction of AI data centers.

Hyosung Heavy Industries has recently been supplying ultra-high-voltage transformers and circuit breakers to 765 kV transmission networks in the US, and these are drawing significant attention in the market. With this latest development, the company is accelerating its push into the US market by offering a "full package of ultra-high-voltage power equipment." Hyosung Heavy Industries is the only power equipment manufacturer in Korea that possesses a full product lineup of ultra-high-voltage circuit breakers ranging from 72.5 kV to 800 kV.

Meanwhile, Hyosung Heavy Industries is seeing strong results in the US power market, having recently signed a contract with a leading US transmission network operator last month to supply power equipment worth KRW 787 billion as the largest-ever deal made by a Korean power equipment company. The company has also invested a total of $300 million (approx. KRW 440 billion) in its Memphis plant in the US, developing it into a key hub for leading the local supply chain. According to Bloomberg New Energy Finance (BNEF), the scale of investment in US power grids is expected to reach $115 billion (about KRW 153 trillion) in 2025. Investment in the transmission sector—which is directly linked to the demand for ultra-high-voltage power equipment—is forecast to skyrocket at an average annual rate of 16% by 2027.