A system for autonomous protection from fires and electrical shock of components used in construction of photovoltaic arrays is disclosed. The system detects conditions that left unattended will result in conflagration of combustible materials and unwanted electrification. The disclosed system provides an active control mechanism that operates to take defective components off line and thus provide protection from fire and electrification hazards that otherwise could arise. The system also provides means for annunciation and notification when actions are taken. The system can be used, for example, to determine that a photovoltaic (PV) module is at risk of conflagration of its flammable structural elements due to intense heat of plasma produced by a direct current (DC) arc at a point in the grid of conductors that collect and carry current from photovoltaic cells exposed to solar irradiation.