ACST-256-1 is a current sense transformer from the ACST-200 series designed for AC current sensing applications. It features a 1:100 turns ratio with an output of 9.7 mV/A ±5%, a maximum load resistance of 1 Ohm, and operates within a frequency range of 50-200Hz. The transformer is constructed with UL class B 130°C materials and supports a primary current range of 0.4 to 30A with a maximum primary resistance of 600 microohms. It includes a sense resistance of 0.8 Ohms ±10% and sense inductance of 0.025H ±30%. The "-1" suffix indicates tin coated primary terminals, and the device offers high-voltage isolation with HI-POT ratings of 4000V (P-S) and 1500V (P-C & S-C), making it suitable for power monitoring, energy metering, and industrial control applications.