Electrical safety test apparatus for detecting leakage current tripping current and proper grounding

Claim 2

Electrical safety test apparatus, comprising in combination: a three-conductor electrical energy cable having a three-pronged plug at one end for receiving electrical energy and adapted to mate with a receptacle in a ground fault interrupter, said cable including an electrical common conductor; a three-socket receptacle for mating with a three-pronged plug of a three wire power cable for an electrically powered tool, said receptacle including an electrical common socket; means for visually indicating electrical current flow; a first circuit adapted to establish a leakage current flow path from the non-common conductor of said energy cable to both non-common sockets of said receptacle through the tool mated therewith and to the common socket; a second circuit including variable resistance means adapted to establish a current flow path from one of the noncommon conductors of said energy cable, said second circuit not passing through said receptacle; and manually operable switch means for selectively connecting said current indicating means to said common energy cable conductor and to either said first circuit, in series with said leakage current flow path, for measuring tool leakage current or to said second circuit, in series with said current flow path from one of the non-common conductors, when said energy cable plug is mated with a ground fault interrupter for measuring the ground fault interrupter current.

Claim 3

Electrical safety test apparatus as set forth in claim 1 further including: a third circuit including resistance means adapted to establish a current flow path from a non-common conductor of said energy cable to the frame of an electrically powered tool mated to said receptacle and to the common socket of said receptacle; said switch means being further operable to selectively connect said current indicating means to the other non-common energy cable conductor and to said third circuit for measuring the amount of electrical continuity between the frame of said tool and its mating receptacle common socket.

Claim 4

Apparatus for testing the safety and operation of electrical circuits and electrically powered devices comprising, in combination: a housing constructed out of substantially non-conductive material; a three-conductor energy cable having a three-pronged pluG at one end adaptable for mating with a receptacle in a ground fault interrupter, said energy cable attached to said housing, and including an electrical common conductor; a three socket receptacle mounted on said housing for mating with the plug on a power cable for an electrically powered tool, one socket of said receptacle being an electrical common; a conductor extending out from said housing for making electrical connection to the frame of an electrically powered tool which is coupled to said receptacle; a current indicating device mounted on said housing; a variable resistance contained in said housing; a fixed resistance contained in said housing; and manually operable electrical switch means mounted on said housing for selectively completing a first circuit path from the two non-common energy cable conductors to the two non-common receptacle sockets and from the common receptacle socket through said current indicating device to said energy cable common conductor for measuring the leakage current flowing through said electrical tool, or for completing a second circuit path from the cable common conductor through said variable resistance and said current indicating device to a non-common cable conductor for measuring cable current flow when said energy cable plug is mated with a ground fault interrupter receptacle or for completing a third circuit path from one non-common cable conductor to said extending conductor through the frame of a tool coupled to the receptacle to the common receptacle socket and through the fixed resistance and the current indicating device to the other non-common cable conductor for measuring electrical continuity between the frame of the electrically powered tool and its mating receptacle common socket.

Claim 5

Apparatus for testing the safety and operation of electrical circuits and electrically powered devices comprising, in combination: a housing constructed out of substantially non-conductive material; a three-conductor energy cable having a three-pronged pluG at one end adaptable for mating with a receptacle in a ground fault interrupter, said energy cable attached to said housing, and including an electrical common conductor; a three socket receptacle mounted on said housing for mating with the plug on a power cable for an electrically powered tool, one socket of said receptacle being an electrical common; a conductor extending out from said housing for making electrical connection to the frame of an electrically powered tool which is coupled to said receptacle; a current indicating device mounted on said housing; a variable resistance contained in said housing; a fixed resistance contained in said housing; and manually operable electrical switch means mounted on said housing for selectively completing a first circuit path from the two non-common energy cable conductors to the two non-common receptacle sockets and from the common receptacle socket through said current indicating device to said energy cable common conductor for measuring the leakage current flowing through said electrical tool, or for completing a second circuit path from the cable common conductor through said variable resistance and said current indicating device to a non-common cable conductor for measuring cable current flow when said energy cable plug is mated with a ground fault interrupter receptacle or for completing a third circuit path from one non-common cable conductor to said extending conductor through the frame of a tool coupled to the receptacle to the common receptacle socket and through the fixed resistance and the current indicating device to the other non-common cable conductor for measuring electrical continuity between the frame of the electrically powered tool and its mating receptacle common socket.