DEVICE FOR PROTECTING ELECTRIC INSTALLATIONS AGAINST OVERHEAT Russian patent published in 2012 - IPC H02H5/04 

FIELD: electricity.

SUBSTANCE: magnetic circuit is designed in the manner of a magnetic amplifier consisting of three rods made of magnetically soft electrical steel. The two lateral rods are positioned symmetrically within the same plane in the manner of a single-phase transformer core (4) and are made of sheet steel. The middle rod is made of massive material, is "П"-shaped and contains a transverse bar and tow side branches. The middle rod is positioned on the core (4) symmetry axis and closely adjoins to the core (4) on its butt ends with the side branches. Power windings are wound onto the rods. In the middle rod a constant magnetisation magnetic flow is provided for. A ferromagnetic insert is inserted into the middle rod in its lower branch and introduced into the thermal impact zone. The ferromagnetic insert is made of a material with second-order phase transition temperature.

EFFECT: invention ensures varied electric energy consumers protection against thermal overload in case of increased current or increased temperature of the product housing to be protected without breaking the control circuit contacts, occasionally - without braking the power circuit.

5 cl, 5 dwg