English to French Tech/Engineering Mechanics / Mech Engineering Filtre autonettoyant

sprinkler nozzles located inside the filter above the filtering sleeves with bimetallic sensor which **cuts in** at a temperature of 74°C, opening the water supply holes and generating cone shaped jets for extinguishing the fire. • If the temperature inside the filter is higher than 74°C, the sprinkler nozzles **cut in**, spraying jets of water mist.

Je ne comprends pas le sens de "cut in" ici. Merci de m'éclairer