Polarity testing adaptor means

Claim 1

A polarity testing adapter means for single phase three wire electrical systems having a hot wire, a ground carrying wire and an equipment grounding wire, comprising in combination, a three wire plug having first and second curreNt carrying prongs, and a third prong connected to the third equipment grounding wire, fuse protected, a socket having first and second current carrying recessed contacts connected to said first and second prongs, and a third recessed contact connected to said third prong and the equipment grounding wire, a fourth recessed contact connected to said third recessed contact for connecting the grounding equipment wire so that a standard three wire plug may be connected to said socket in first and second positions for reversing polarity, a rotatable disc rotatably mounted on the socket having slotted holes to receive a standard three wire plug in one position when a plug engages the socket said rotatable disc being disposed to counterclockwise or clockwise rotation and settable to a position 180 degrees away for a second position entry for said plug, said rotating disc serving as a mask to block one entry position, an arrow pointer attached to said rotatable disc for indicating one or more reference positions of the rotating disc, and circuit wires connected to said plug and said socket for testing or correcting said circuit.