Two-Core Low-Voltage Current Transformers (Rectangular Window-Type)

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Two-Core Low-Voltage Current Transformers (Rectangular Window-Type) - CIC

CIC | CHALLENGE INDUSTRIAL CO., LTD., since 1974, is a global supplier of Two-Core Low-Voltage Current Transformers (Rectangular Window-Type). 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.

Two-Core Low-Voltage Current Transformers (Rectangular Window-Type)

ES-1S-B Series

2 cores. Rectangular, low-voltage, resin-insulated current transformers for switchgear-panel makers et al. Dual-purpose current transformer, for use with measuring or monitoring instruments in addition to protective relays (simultaneously). This current transformer can be mounted on a busbar or fixed directly to the switchgear panel.

About the Product

Intended for switchgear-panel manufacturers and other users, these rectangular, resin-insulated, low-voltage window-type current transformers are self-extinguishing and highly water-resistant. Each of these current transformers can be mounted on a busbar (the busbar can be either horizontally or vertically installed in the switchgear panel). Alternatively, the current transformer can be fixed directly to the switchgear panel; in this case, wiring can be done with a busbar or with insulated copper wires. The product comes with one type of mounting accessories, to be chosen by the customer from available options.

Features of the ES-1S-B Series

  • Two-core
  • Window-type
  • Dual-purpose: Use with measuring or monitoring instruments in addition to protective relays (simultaneously)


  • 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: a choice of mounting accessories
  • Other specifications and standards available upon request

Selection Table

Other standards and specifications available.

Current (A)
Secondary Current (A)Burden/Accuracy
Core 1Core 2
ES-1S-AES-1S-60A400~8005 - 30VA/1.0 or 15VA/0.52.1Single-Core
ES-1S-80A *600~12005 - 30VA/1.0 or 15VA/0.52.1Single-Core
ES-1S-100A *1000~20005 - 30VA/1.0 or 15VA/0.52.2Single-Core
ES-1S-120A *2500~40005 - 40 VA/1.0 or 30VA/0.53.7Single-Core
ES-1S-165A *4000~70005 - 40 VA/1.0 or 30VA/0.54.3Single-Core
ES-1S-BES-1S-100B *1000~20005515VA/5P20+30VA/0.510Two-Core
ES-1S-120B *2500~40005515VA/5P20+30VA/0.59.5Two-Core
ES-1S-CES-1S-165C800~10005 - 7.5VA/5P106Split-Core
1250~16005 - 10VA/5P106Split-Core

*  Models marked with an asterisk require caution when mounted on a busbar. Care must be taken, when the switchgear panels are being moved or when during an earthquake, to prevent the current transformer from sliding due to its weight.

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