Abstract: Methods and apparatus for performing a “safe working practice” known as a live-dead-live test on a voltmeter to confirm that the meter is operational before being relied upon to verify an electrical circuit, component, device and/or equipment is de-energized. The live-dead-live tester is transported to the location at which the voltmeter will be used to verify an electrical circuit, component, device and/or equipment is de-energized. The voltmeter is set to read either AC or DC voltage. The voltage selection switch on the live-dead-live tester is then moved from the “off” position to the position that will output the same type of voltage that the voltmeter is set to indicate. The LED for the type of voltage selected on the LDL will then illuminate, indicating that the LDL battery is good and that it is supplying the output selected. The voltmeter operability will then be verified.

Abstract: Systems and methods for locating any grounded circuit on an ungrounded AC or DC system without de-energizing the circuit, and enabling isolation of the grounded component of the circuit. A load is fed through an isolation device, such as a transformer for AC systems or a DC-to-DC converter for DC systems, and isolated from the normal distribution system without ever being de-energized. Once the isolating device is paralleled with the normal source for the load, the normal source is removed, leaving the load energized and fed by the isolating device. A ground detector relay is added at the secondary side of the isolation device to detect unwanted grounds along with a ground locating method to isolate the source of the ground, such as by oscillating the ground current. Once the grounded circuit is located, further troubleshooting may be performed to isolate the grounded component.