Leakage current testing circuit

A leakage current testing circuit to be connected to an energized three wire outlet and for use where either the outlet is protected by a ground fault circuit interrupter device or such a device is to be tested prior to its installation, said testing circuit including three parallel lines of which the second is neutral and the third a ground, first and second parallel leads connecting said first and neutral lines, the first parallel lead including a voltmeter and the second parallel lead a potentiometer adjustable to the prevailing first line voltage and including a lead for the adjusted output, first and second tripping leads connected to the ground line, the first tripping lead including parallel resistors, a potentiometer adjustable in a milliampere range and a milliammeter, and the second tripping lead including a digital readout timer of a type latching its reading when the device being tested trips and a timer lead, first switch means in control of said tripping leads and operable to close them in the alternative or simultaneously, second switch means having first and second operative positions in the first of which the adjusted output lead is closed to said tripping leads and said timer lead is connected to said neutral line, the first position used when the circuit is protected by a ground fault circuit interrupter device to be tested and the second position used when an external test is to be made of such a device prior to its installation, and said circuit including an external test section provided with first and second outlets each of which includes first and second leads to which said device is to be connected, and when said second switch means is in its second position with the device to be tested connected to said leads, the adjusted output lead is closed to the external test section through the device and the tripping leads, and the timer lead closed through the device to the neutral line, whereby in either position of the second switch means, device leakage can be measured in terms of milliamperes and then in terms of milliseconds at an established milliampere value.