Patent ID: 9728357
Date: 2017-08-08
CPC Classifications: H01F,H01H,H02H

Claim:
1. A safety device suitable to be associated with a power transformer containing a cooling liquid, the safety device comprising: a shaped body having an inner chamber configured to be at least partially immersed in cooling liquid and inside which gas can accumulate; a first floating element and a second floating element configured to be at least partially immersed in and moved by cooling liquid; switching means for actuation by said first floating element when the gas accumulated is such that a level of cooling liquid in the inner chamber reaches a predetermined first threshold level, and by said second floating element when the gas accumulated is such that the level of said cooling liquid in the inner chamber reaches a lower predetermined second threshold level, respectively; and wherein said first floating element and said second floating element are mounted on and are configured to move linearly along a reference axis relative to one or more corresponding guiding supports.