Abstract: A protective system for reducing the possibility of injury to individuals or damage to electrical equipment due to a fault in a coaxial drop cable connected between a tap unit receiving both RF signals and AC power from a main distribution line and a premise unit coupling the RF signals to RF receiving equipment and the AC power to other AC powered equipment at user premises. The tap unit includes a circuit having a first line connected at spaced points to an inner conductor with the RF signals flowing through the inner conductor and the AC power flowing through the first line. A regulated monitoring current flows from an AC to DC converter in the first line to a difference amplifier having a pair of inputs with a resistor connected between the two, whereby the difference amplifier serves to monitor the monitoring current by measuring the voltage drop across the resistor.

Abstract: A protective system for reducing the possibility of injury to individuals or damage to electrical equipment due to a fault in a coaxial drop cable connected between a tap unit receiving both RF signals and AC power from a main distribution line and a premise unit coupling the RF signals to RF receiving equipment and the AC power to other AC powered equipment at user premises. The tap unit includes a circuit having a first line connected at spaced points to an inner conductor with the RF signals flowing through the inner conductor and the AC power flowing through the first line. A regulated monitoring current flows from an AC to DC converter in the first line to a difference amplifier having a pair of inputs with a resistor connected between the two, whereby the difference amplifier serves to monitor the monitoring current by measuring the voltage drop across the resistor.