They are frequently used to detect ground faults or in applications where applied voltage varies significantly. DC versions can sense currents as low as 0.61mA and tolerate voltages up to 10X minimum. AC versions can sense currents as low as 0.74mA and can tolerate voltages up to 5X minimum. Single pole DC coil versions use as little as 12mW of power while double pole versions can be as low as 60mW.