Patent ID: 9620956
Date: 2017-04-11
CPC Classifications: H01L,H02H,H02S,Y02E

Claim:
1. A junction box for a solar panel is provided for electrically connecting external connecting lines to a solar panel, wherein the junction box includes: a junction box housing, input-side connecting elements for connecting voltage-carrying conductors of the positive pole and negative pole of the solar panel, output-side connecting elements for connecting a first and second external connecting lines to the junction box, and a protective circuit that defines an operating state and a protected state, wherein in the operating state, the first external connecting line is electrically connected to the voltage-carrying conductor of the positive pole of the solar panel and the second external connecting line is electrically connected to the voltage-carrying conductor of the negative pole of the solar panel for feeding the electrical power produced by the solar panel into the power grid via the first and second external connecting lines; wherein the protective circuit comprises a short-circuiting switch between the output-side connecting elements of the first and second external connecting lines and an isolating switch; and wherein in the protected state, the short-circuiting switch short-circuits the output-side connecting elements of the first and second external connecting lines to each other and the isolating switch disconnects the short-circuiting switch from the solar panel on at least one side, further including a current sensor connected between one of the external connecting lines and the short-circuiting switch for measuring the current flowing in the external connecting lines in the protected state, wherein the protective circuit is adapted to switch from the protected state into the operating state in response to an initial current flowing through the external connecting lines in the protected state.