An electrical link including a protective sheath surrounding at least two conductors each covered by an insulating jacket and an electrical protection system includes: a conductive sheath on each of the insulating jackets, a circuit breaker for each conductor; a direct current generator generating a direct current to be successively applied to each conductive sheath; and a leakage current detection circuit for each conductive sheath; a sequencer successively supplying the direct current to each conductive sheath; the detection circuit measures a current in each conductive sheath and compares a voltage proportional to the current to a first and second ranges of values, the detection circuit activating the circuit breaker if: the voltage is outside of the first range of values while the current generator generates a non-zero current; or the voltage is outside of the second range of values.