A stand-alone remote sensor arrangement for monitoring parameter activity in a cable, the arrangement comprises a sensor unit and a power source unit connected to each other by a connecting cable, and a control unit, the power source unit is configured to supply energy to said sensor unit, the sensor unit comprises a shielded housing enclosing a toroid-shaped core configured to be fixed around the cable to be monitored, and the toroid-shaped core is provided with at least one gap where a Hall sensor element is arranged, wherein the remote sensor arrangement is configured to be operated in a low current consumption mode and in a measurement mode, in which measurement mode said Hall sensor element is configured to sense a predetermined parameter activity, e.g. flowing current, of said cable, and that said control unit is configured to change the mode of operation of said sensor arrangement, the sensor unit further comprises a sensor activation unit arranged and structured to sense parameters related to magnetic field variations in said core caused by said parameter activity of said cable, and to generate a sensor activation signal including parameter values dependent on said sensed parameters, wherein the control unit is configured to receive said sensor activation signal and to evaluate said parameter values in relation to predetermined mode changing criteria, and to change mode of operation of said sensor arrangement dependent on the result of said evaluation, characterized in that said sensor activation unit is a coil integrated in a printed circuit board arranged in said housing, or said sensor activation unit is a coil that encircles a cross-sectional part of said core by being wound around said part of the core. the power source unit is configured to supply energy to said sensor unit, the sensor unit comprises a shielded housing enclosing a toroid-shaped core configured to be fixed around the cable to be monitored, and the toroid-shaped core is provided with at least one gap where a Hall sensor element is arranged, wherein the remote sensor arrangement is configured to be operated in a low current consumption mode and in a measurement mode, in which measurement mode said Hall sensor element is configured to sense a predetermined parameter activity, e.g. flowing current, of said cable, and that said control unit is configured to change the mode of operation of said sensor arrangement, the sensor unit further comprises a sensor activation unit arranged and structured to sense parameters related to magnetic field variations in said core caused by said parameter activity of said cable, and to generate a sensor activation signal including parameter values dependent on said sensed parameters, wherein the control unit is configured to receive said sensor activation signal and to evaluate said parameter values in relation to predetermined mode changing criteria, and to change mode of operation of said sensor arrangement dependent on the result of said evaluation, said sensor activation unit is a coil integrated in a printed circuit board arranged in said housing, or said sensor activation unit is a coil that encircles a cross-sectional part of said core by being wound around said part of the core.