An overcurrent-protection network for a transmission line logic system is disclosed, including a line switch in said line subject to over-current conditions and an added threshold-responsive logic element whose output in response to detection of over-current conditions triggers said protected logic elements to open said line switch via a over-current condition responsive gate whose output supplies a control signal to the line switch. A supplementary network is provided to reclose said switch; this may comprise a time-delay mechanism for resetting a bi-stable element whose output controls said switch after a reasonable interval. Alternatively, the supplementary network may comprise a resistor bridging the switch to maintain minimal current flow to said protected logic elements, which thereby are responsive to the next succeeding change in line current or signal, to change state and re-close said line switch, thereby restoring initial conditions.