Model 5AS Instrument Current transformer

  • Standard 1 or 5 amp AC out, 600VAC rated
  • Up to C800 rating, many sizes
  • Select from 100A, 6,000A input
  • Ratio accuracies per C57.13-2007>
  • Shock protection diodes
  •  Meets UL2808, IEC61010-1 & C57.13
  • Overvoltage Category CAT IV rated


The model 5AS Instrument Current Transformer (CT) is a traditional current ratio instrument transformer. The standard sizes are UL Listed under UL2808 and IEC61010-1. The 5AS series current transformers incorporates an internal transient voltage suppressors (TVS) for temporary shock protection in case the output leads are not terminated, but the leads must be shorted using a shorting bar if connected for long periods of time.  CAUTION: The TVS is only for temporary shock protection — it will overheat if the CT is installed on a live power conductor with the output leads disconnected from the shorting block.  The output is linear from 10% to 100% of range with a ratio accuracy of +/- 1% with optional Class 0.5. Accuracy can be adjusted to +/-0.3% full scale when known burden value is provided by customer. Typically the 5AS will meet the accuracy requirements of C57.13-2008.

Instrument current transformers, Model (series) 5AS, are traditional current transformers with either 1 amp or 5 amp output current. Sentran Corporation manufacturers instrument current transformers in split core, solid core or toroidal (bushing or donut) styles for input currents up to 6000A. For custom made instrument current transformers, Sentran Corporation can provide many sizes with input currents up to 25,000A. The Model 5AS instrument current transformers are manufactured in the Pacific Northwest in Salem, Oregon ,USA. The current transformers are provided with 12 AWG type 1230 lead wires or terminal blocks as requested. Model 5AS is also available for outdoor applications when encapsulated or potted.