Patent ID: 8766472

Claim:
An apparatus for shutting off a power supply for construction equipment or a vehicle driven by an engine, including a power supply, functional electrical devices connected to the power supply, a key switch managing the power supply, and a main relay applying or shutting off the power supply to the functional electrical devices in accordance with a state of the key switch, the apparatus comprising: manipulation sensing means; a control relay installed between the key switch and the main relay to apply a key switch signal to a driving unit of the main relay if the electricity is not applied to the driving unit and to shut off the key switch signal to the driving unit of the main relay if the electricity is applied to the driving unit; and a controller receiving a manipulation signal from the manipulation sensing means and shutting off the power by driving the control relay if there is no manipulation signal for a predetermined time; wherein the manipulation sensing means comprises means for determining that there is no manipulation if a fuel control amount of the engine, an engine load, or an engine speed is kept at a predetermined value for the predetermined time.