ACST-259-1 is a current sense transformer from the ACST-200 series designed for AC current sensing applications. It features a 1:300 turns ratio with an output of 31.7 mV/A ±5%, a maximum load resistance of 10 Ohms, and operates within a primary sense frequency range of 50-200Hz. The transformer is constructed with UL class B 130°C materials and has a primary current range of 0.4 to 30A with a maximum primary resistance of 600 microohms. With high-voltage isolation ratings of 4000V (P-S) and 1500V (P-C & S-C), it is suitable for energy metering, power monitoring, and current measurement applications where reliable isolation and accurate sensing are required.