Low-Voltage Split-Core Current Transformers (Rectangular Window-Type) for Protection

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Low-Voltage Split-Core Current Transformers (Rectangular Window-Type) for Protection - CIC

CIC | CHALLENGE INDUSTRIAL CO., LTD., since 1974, is a global supplier of Low-Voltage Split-Core Current Transformers (Rectangular Window-Type) for Protection. CIC specializes in the manufacture of instrument transformers, distribution transformers, detuned reactors, epoxy insulators, electronic energy meters, etc. Also provided or distributed are a wide range of other electrical or electronic apparatus.

Certified to ISO 9001, CIC ensures superior quality of its goods through such advanced technologies and materials as Swiss-manufactured equipment (for the production of resin insulators), Araldite® epoxy resin, and technology transferred from Messwandler-Bau (MWB) of Germany.

Backed by 44 years of experience, CIC offers custom-made products, OEM/ODM services, and technical support tailored to the needs of its discerning clientele.

Low-Voltage Split-Core Current Transformers (Rectangular Window-Type) for Protection

ES-1S-C Series

Split-core, rectangular, low-voltage, resin-insulated protective current transformers for switchgear-panel makers et al. Installing onto an existing power system with ease.

About the Product

Intended for switchgear-panel manufacturers and other users, these resin-insulated, low-voltage, window-type current transformers have a rectangular shape and are designed for wiring through a busbar. Each of the these current transformers can be mounted on a busbar. Alternatively, it can be fixed onto a switchgear panel through the provided metal installation fittings, which allow both horizontal and vertical installation. Two types of metal installation fittings are included with each ES-1S-C current transformer. As an option, insulated wires can be used instead as the primary conductor. Caution should be exercised if any ES-1S-C current transformer with a current of more than 1200A is mounted on a vertically installed busbar. In this case, care must be given, when the switchgear panels are being moved or when during an earthquake, to prevent the current transformer from sliding due to its weight. Insulated with self-extinguishing resin, ES-1S-C current transformers are characterized by excellent insulation and moisture resistance.

ES-1S-C Series

  • Single-core
  • Split-core window-type
  • For protective purposes
  • Can be installed onto an existing system without cutting (or removing) the primary busbar or insulated wires.


  • Standard: IEC or IEEE
  • For indoor use
  • Rated voltage: ≦ 0.72 kV
  • Frequency: 50/60 Hz
  • AC/BIL: 3/- kV
  • Ith = 40 In/1S
  • Included accessories: two types of metal installation fittings
  • Other specifications and standards available upon request

Selection Table

Other standards and specifications available.

Series Model Primary
Current (A)
Secondary Current (A) Burden/Accuracy
Core 1 Core 2
ES-1S-A ES-1S-60A 400~800 5  -  30VA/1.0 or 15VA/0.5 2.1 Single-Core
ES-1S-80A 600~1200 5  -  30VA/1.0 or 15VA/0.5 2.1 Single-Core
ES-1S-100A 1000~2000 5  -  30VA/1.0 or 15VA/0.5 2.2 Single-Core
ES-1S-120A 2500~4000 5  -  40 VA/1.0 or 30VA/0.5 3.7 Single-Core
ES-1S-165A 4000~7000 5  -  40 VA/1.0 or 30VA/0.5 4.3 Single-Core
ES-1S-B ES-1S-100B 1000~2000 5 5 15VA/5P20+30VA/0.5 10 Two-Core
ES-1S-120B 2500~4000 5 5 15VA/5P20+30VA/0.5 9.5 Two-Core
ES-1S-C ES-1S-165C 800~1000 5  -  7.5VA/5P10 6 Split-Core
1250~1600 5  -  10VA/5P10 6 Split-Core
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