The utility model discloses a to the in -depth study who tests electric hand car and grounding handcart theory of operation, the electro -magnet of installation control handcart business turn over tocooperation computer no. 5 is prevented carrying on the shutting function perfectly, an it goes into electrified interval blocking device to be used for electric power handcart to prevent mistake, including business turn over car hole, handcart body, secondary bolt shutting push pedal still includes the electro -magnet, five prevents tool to lock and secondary bolt, wherein handcart body's middlepart and bottom is arranged in to the electro -magnet, prevents the tool to lock by five and control, on secondary bolt shutting push pedal was arranged in to the secondary bolt, cooperation no. 5 prevented that the tool to lock carries out forced locking. The utility model discloses a benefit lies in: the mistake will you please be prevented when solving cubical switchboard commentaries on classics maintenance and an electrified spaced difficult problem, ability improve equipment reliability of operation, especially greatly reduced operation personnel's the safe risk of operation is gone into. Than present grounding handcart, test the electric hand car, have that the quality is light, with low costs, the function is more perfect, safer, reliable characteristics of operation.