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

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

ES-1S-A Series

1 core. Rectangular, low-voltage, resin-insulated current transformers for switchgear-panel makers et al. For use with measuring or monitoring instruments. 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-A Series

  • Single-core
  • Window-type
  • Designed to be used with measuring or monitoring instruments


  • Standard: IEC or IEEE
  • For indoor use
  • Rated voltage: ≦ 0.72 kV
  • Frequency: 50 or 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.

Related Products

Download Materials

  • Tag
  • Window-Type Current Transformers
  • CT
  • CT PT
  • Instrument Transformers
  • LV Current Transformer
  • Low Voltage Current Transformers
  • Low-Voltage Current Transformers
  • LV Current Transformers
  • LV CT