The company was founded in in Switzerland by Emil Haefely, an inventor who played a decisive role in the development of the electrotechnical industry at beginning of the th century. With the patent of the OIP Condenser type bushing in by Emil Haefely, the company became a pioneer in Oil type bushings. Trench France is part of the Trench & HSP Bushing group belonging to Siemens with locations in France (Trench France), Germany (HSP) and China (THVS). This close cooperation for innovation and design is supported by Siemens process and manufacturing know how. In , the Trench Group decided for Trench France to focus specifically on bushings by making extensive manufacturing investments and improving all customer relevant processes.

Trench Italy is located in the village of Cairo Montenotte, in the northwest of Italy near the town of Savona and approximately km from Genoa harbor. The Company was founded in under the name of Scarpa e Magnano. In came the merger with Magrini and the whole enterprise was acquired by Merlin Gerin in , before being integrated in the VATECH group in and finally in the Trench Group in . Since the production start of oil insulated instrument transformers as early as , Trench Italy has a high competence in the design and manufacturing of high voltage instrument transformers. The European production of oil insulated voltage and current transformers, capacitor voltage transformers, grading capacitors and special instrument transformers of the Trench Group is concentrated in Cairo Montenotte on a . m² total surface. Significant investments in production and testing facilties since as well as the outstanding technical expertise allowed Trench Italy to introduce state-of the art manufacturing processes that are leading to high quality products and a proven reliability.

Siemens Limited, launched manufacturing of High Voltage Instrument transformers in , in the existing HV products factory at Aurangabad in India. The state-of-the-art facility is producing CVTs with Oil insulation and CT/PTs with SF insulation and is the only factory in India manufacturing SF CT/PTs with Composite insulators with technology support by Trench Germany. The factory also supplies GIS components (Instrument Transformers and Bushings) and Grading Caps to Siemens India. With a total area of Sq. Meters, Siemens Instrument Transformers is the market leader for CVTs in the domestic market. For SF CT/VTs, the facility has its own set up of Composite insulators. There are some key utilities/ industries from Power Generation in India, who have completely switched their CT/PT requirements to SF technology. Siemens India is also working continuously together with Global R&D on new generation and digitalized products to serve the customers with advancements further.

Trench High Voltage Products Ltd., Shenyang, (THVS) successor of Trench Fushun Bushing Co., Ltd., was established in and is a member of the global Trench Group. Being a member of Trench Group, THVS benefits from strong technical support and global R&D activities and innovations from group to serve local and oversea customers for various HV applications. The factory is well equipped with advanced manufacturing, assembly, testing equipment and HV test labs. A dedicated team of experienced engineers and skilled workers is working hard to meet customers’ satisfaction. THVS is certified for ISO , ISO & OHSAS . THVS is not only a market leader for bushings in China and various export markets, but also a successful manufacturer of oil insulated instrument transformers with customer references worldwide. The Instrument Transformers product portfolio includes: • Oil insulated Current Transformers (up to kV) Oil insulated Capacity Voltage Transformer (up to kV) The Bushings product portfolio includes: • Oil Impregnated Paper Bushings (from . kV &#; kV up to , A) • Epoxy Resin Impregnated Paper Bushings (from . kV &#; kV up to , A)

HSP Hochspannungsgeräte GmbH – known as HSP – has a long history in manufacturing bushings and high voltage equipment. Over years ago it was founded as a division of Meirowsky & Co., was then taken over by Dielektra AG and later by Felten & Guilleaume Energietechnik AG (F&G). Since HSP is an independent company. We develop and manufacture condenser graded high voltage bushings in RIP technology (resin impregnated paper) and RIS technology (resin impregnated synthetic) up to kV rated voltage for AC applications and HVDC transmissions. Our bushings are suitable for power transformers, switchgears, generators, HVDC and for test equipment – meeting all international standards. By consistently maintaining the highest quality standards, we have become a leader on the world market for high-voltage bushings in recent decades.