A method for monitoring at least one electrical connection in a power distribution block , wherein the power distribution block includes a housing , at least two terminals located in the housing , each terminal comprising a cavity with a contact surface within the cavity and a corresponding set screw , the cavity configured to receive a wire to be compressed by the set crew against the corresponding contact surface resulting in the electrical connection, the method comprising: generating, with at least one transducer , ultrasonic pulses in the power distribution block; receiving, with the at least one transducer , ultrasonic signals based on the ultrasonic pulses; and determining, with a controller coupled to the at least one transducer , a status of at least one electrical connection in the power distribution block based on at least one characteristic of the ultrasonic signals received by the at least one transducer ,wherein receiving the ultrasonic signals includes receiving, with the at least one transducer , a series of reflections from the at least one electrical connection in the power distribution block ; and wherein determining the status of the at least one electrical connection includes identifying a most prominent reflection in the series of reflections, determining a round-trip time of the most prominent reflection in the series of reflections, and identifying whether the at least one electrical connection in the power distribution block has loosened or been overtightened based on the round-trip time of the most prominent reflection in the series of reflections, and wherein identifying includes analyzing the round-trip time of the most prominent reflection in the series of reflections over time and identifying that the at least one electrical connection in the power distribution block has loosened or been overtightened in response to a determination that the round-trip time of the most prominent reflection in the series of reflections has increased due to changes in electrical and mechanical impedance of the power distribution block. generating, with at least one transducer , ultrasonic pulses in the power distribution block; receiving, with the at least one transducer , ultrasonic signals based on the ultrasonic pulses; and determining, with a controller coupled to the at least one transducer , a status of at least one electrical connection in the power distribution block based on at least one characteristic of the ultrasonic signals received by the at least one transducer ,wherein receiving the ultrasonic signals includes receiving, with the at least one transducer , a series of reflections from the at least one electrical connection in the power distribution block ; and wherein determining the status of the at least one electrical connection includes identifying a most prominent reflection in the series of reflections, determining a round-trip time of the most prominent reflection in the series of reflections, and identifying whether the at least one electrical connection in the power distribution block has loosened or been overtightened based on the round-trip time of the most prominent reflection in the series of reflections, and wherein identifying includes analyzing the round-trip time of the most prominent reflection in the series of reflections over time and identifying that the at least one electrical connection in the power distribution block has loosened or been overtightened in response to a determination that the round-trip time of the most prominent reflection in the series of reflections has increased due to changes in electrical and mechanical impedance of the power distribution block. <EOS>