Siemens SF6 Insulated Combined Instrument Transformers Air-insulated switchgear

SF₆ insulated combined instrument transformers are used to convert high transmission line voltages and currents (voltage up to 800kV and current up to 6000 A) to standardized low and easily measurable values, which will be used for metering, protection and control of the high voltage system. As such, the need for accurate and reliable voltage and current transformation is essential.

The reliability and security of Trench gas-insulated instrument transformers is based on over 50 years of innovation with gas-insulated units operating under a wide range of environmental conditions. Combined instrument transformers also ensure suitable electrical insulation between high voltage and low voltage measuring equipment.

Our gas-insulated combined transformers are compliant to the latest international safety standard requirements in terms of explosion-proof, insulating material multiple chopped ageing, seismic qualification and extreme temperature conditions.

Modern production and testing facilities guarentee not only short delivery times but also a reliable operation for many years.

SF6 Insulated Instrument Transformers General Features:

• Complete portfolio available from 72 to 800 kV
• Meet all lEC and ANSI metering and protection classes, including special core classes TPS, TPX, TPY and TPZ ones
• Rated primary Voltage up to 800 kV
  Rated primary current up to 6000A
• CT ratings:
  Rated secondary current of 1A, 2A or 5A
  Rated short time thermal currrent up to 80kA Rated short circuit withstand up to 200 kAp
• VT ratings:
  Maximun simultaneous burden [IEC cl. 0,2] 150 VA
  Maximun simultaneous burden [ANSI] 0,3Z/0,15Y
  Thermal limiting output up to 3000 VA
• Suitable also for Line Discharge use
• Wide-range ferroresonance-free design without the use of an external damping device
• Fully type tested according to international standards
• Special tests are also available to meet specific customer requirements

Product Design:

• SF₆ is the main insulation medium
• Explosion-proof design
• External insulation with composite insulator; porcelain insulator available on request
• External parts made of aluminum or stainless materials
• Bar-type primary conductor allows higher short circuit current and avoids !arge voltage drop across the primary winding
• Available to withstand:
  • Internal arc effects [according to IEC 61869 – protection stage 1 -]
  • Heavy seismic solicitations, according to IEC 62271, IEEE 693 and specific customers‘ requests

Siemens Transmission Products – Leader in innovations with comprehensive, connective and sustainable portfolio

Transmission products play a vital role in the energy value chain. Siemens Transmission Products provides all key elements including power transformers and distribution transformers as well as gas-insulated and air-insulated switchgear and components. Products are offered individually, bundled or with related engineering upgrade to systems. Our products offer low life cycle costs with maximum availability, highest efficiency and short commissioning times.

We are driving technology innovations not only regarding the performance of transmission products but also in the area of sustainability and eco efficiency. By merging physics and data we enable new products and applications: Sensformer® and Sensgear®. With our global factory network and leading innovations we provide the highest level of quality and reliability to our customers: TSOs, DSOs, power producers, EPCs and industrial companies.