The Izolyator high-voltage bushings have been successfully tested with the maximum possible seismic impact

On August 11–18, 2025, the Izolyator high-voltage bushings were successfully tested with the maximum possible seismic impact at the Indian Central Power Research Institute by order of the Turkish Electricity Transmission Company.

Central Power Research Institute (CPRI) is the powerhouse of the Indian electrical industry, being an autonomous Society under the Ministry of Power, Government of India. The Institute functions as a centre for applied research in electrical power engineering assisting the electrical industry in product development and quality assurance. CPRI also serves as an independent authority for testing and certification of power equipment. The Institute has several Research and Testing laboratories engaged in different specialized fields. The headquarters of the Institute is in Bangalore.

Turkish Electricity Transmission Company (Türkiye Elektrik İletim A.Ş. — TEİAŞ) is a state power grid company engaged in electricity transmission with construction of new power lines and development of the country’s infrastructure using advanced technologies. The head office of TEIAŞ company is located in Ankara.

Voltage class 420 and 172 kV bushings were tested at the CPRI laboratory in Bangalore with the participation of specialists from the Izolyator Group.

Three-axis multi-frequency tests in accordance with IEC 60068-2-57 and IEC 60068-3-3 standards were performed with simultaneous but independent inputs along the horizontal X, Y, and vertical Z axes, each of which provided the required response spectrum in accordance with the customer's specification and the IEEE 693 international standard.

Participants of seismic tests of Izolyator high-voltage bushings at the Indian Central Power Research Institute by order of the Turkish Electricity Transmission Company

The tests were conducted in two stages. In the first stage (medium seismic impact level), accelerations of the performance level spectrum corresponding to 1g were applied. In the second stage (high seismic impact level), accelerations of the performance level spectrum corresponding to 2g were applied.

It should be emphasized that according to current standards, these impacts are the maximum possible for high-voltage equipment and exceed the corresponding impacts in earthquakes with an intensity of 9 points on the MSK-64 scale.

Following the completion of seismic testing, the bushings were sent to the high-voltage laboratory for electrical testing, which included elevated voltage testing at 50 Hz, impulse testing, and partial discharge measurements.

The positive results of the electrical testing confirmed that the bushings had not changed their condition as a result of seismic impact.

The need for these tests was necessitated by the revision of power equipment requirements due to the high seismic activity in Turkey in recent years.

Thus, Izolyator has once again confirmed its reputation as a manufacturer of high-voltage insulating equipment that maintains stable operation under extreme conditions, including in seismically active regions.