CIRCUIT FOR PREVENTING OVERLOAD AND FALL OF CRANE

摘要

PURPOSE: A circuit of a crane is provided to prevent the overload and fall of a product by blocking a main power supplying electronic contactor through detecting the abnormality of the crane for the entire operation of the crane. CONSTITUTION: A circuit of a crane comprises a magnetic switch(11); a brake; an input unit(30) detecting the brake when the crane moves or stops; a timer unit outputting a blocking signal by a detecting time over a reference time; and a crane power blocking circuit. The overload is generated in the malfunction of an overhead crane thyristor, and a melting-bonding and winding up and down of a DC magnet brake electronic contactor tip. The circuit preventing the overload of the crane decides the reason of the overload to prevent a product drop and the damage of the installation by stopping the overhead crane in advance.