An electrical fault detection device, comprising: a high-frequency sensor coupled to an electrical distribution line for detecting a high-frequency component of a sinusoidal electrical power signal; a series arc-detection circuit coupled to the high-frequency sensor and including: a high-frequency module configured to identify a broadband portion of the high-frequency component; a detection module configured to: rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on characteristics of the broadband portion, the characteristics including: a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the characteristics has a respective weighted value compared with the other characteristics for adjusting the fault count value; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a trip circuit responsive to the series-arc trip signal for opening the electrical distribution line. a high-frequency sensor coupled to an electrical distribution line for detecting a high-frequency component of a sinusoidal electrical power signal; a series arc-detection circuit coupled to the high-frequency sensor and including: a high-frequency module configured to identify a broadband portion of the high-frequency component; a detection module configured to: rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on characteristics of the broadband portion, the characteristics including: a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the characteristics has a respective weighted value compared with the other characteristics for adjusting the fault count value; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a high-frequency module configured to identify a broadband portion of the high-frequency component; a detection module configured to: rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on characteristics of the broadband portion, the characteristics including: a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the characteristics has a respective weighted value compared with the other characteristics for adjusting the fault count value; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and rectify the sinusoidal electrical power signal; store a fault count value representing a propensity of the high-frequency component to be an arc fault; adjust the fault count value based on characteristics of the broadband portion, the characteristics including: a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the characteristics has a respective weighted value compared with the other characteristics for adjusting the fault count value; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a quarter-cycle amplitude of the broadband portion during the quarter cycle following a zero crossing of the rectified sinusoidal electrical power signal, a non-quarter-cycle amplitude of the broadband portion after the quarter cycle, and a rate-of-change of the amplitude of the broadband portion, wherein each of the characteristics has a respective weighted value compared with the other characteristics for adjusting the fault count value; and generate a series-arc trip signal if the fault count value exceeds a fault count threshold; and a trip circuit responsive to the series-arc trip signal for opening the electrical distribution line.