Abstract: A device and method of protecting a link in a medium, high, or very high voltage power network, with current and voltage transformers and trip circuits being disposed on the link. The protection device includes a mechanism to directly connect to a power supply, to the current and voltage transformers, and to the trip circuits, via analog links, and a mechanism to convert from analog to digital that is connected to a central processor unit via a digital link, the analog-digital conversion mechanism including an integrated test plug socket function.

Abstract: A protection device is to be associated in an electrical circuit (3) with a current-breaker device (20) including at least one pair (2) of contacts. The protection device includes a measuring device (1.1) for detecting a fault in the electrical circuit, at least one pair (6) of trigger contacts adapted to assume a closed or open position and to energize a coil for operating the pair (2) of contacts of the current-breaker device (20), and a control device (1.2) for commanding closing the pair (6) of trigger contacts in the event of detecting a fault, launching a time-delay and opening the pair of trigger contacts in the event of disappearance of the fault at the end of the time-delay, and barring opening pending operator intervention if the fault persists at the end of the time-delay.