Voltage verification unit
A voltage verification unit and method for determining the absence of potentially dangerous potentials within a power supply enclosure without Mode 2 work is disclosed. With this device and method, a qualified worker, following a relatively simple protocol that involves a function test (hot, cold, hot) of the voltage verification unit before Lock Out/Tag Out and, and once the Lock Out/Tag Out is completed, testing or “trying” by simply reading a display on the voltage verification unit can be accomplished without exposure of the operator to the interior of the voltage supply enclosure. According to a preferred embodiment, the voltage verification unit includes test leads to allow diagnostics with other meters, without the necessity of accessing potentially dangerous bus bars or the like.
1. A voltage verification device comprising:
a. a series of at least three indicators;
b. a mechanism for connecting each individually or all of said indicators to each of the three phase outputs of a three phase power supply comprising: at least one plug for engaging the output of said three phase power supply; circuitry for controllably conveying each or all of said three voltage phases from said at least one plug to said series of indicators and a switch for selecting individual of collective combinations of each of said three phase voltages for delivery to said series of indicators; and
c. a mechanism for delivering the three phases of voltage from said three phase power supply to said series of three indicators.
2. The voltage verification device of claim 1 further including a voltmeter that includes a switch for selectively introducing or excluding the output of said three phase power supply to said voltmeter.
3. The voltage verification device of claim 2 further including a fuse block between said voltmeter and said output from said three phase power supply for the protection of said volt meter.
4. The voltage verification device of claim 1 wherein said series of indicators comprises a set of three LEDs and said circuitry for controllably conveying each or all of said three voltage phases from said at least one plug to said series of indicators and a switch for selecting individual of collective combinations of each of said three phase voltages includes an appropriate arrangement of capacitors and resistors to apply the appropriate activation voltages to said set of three LEDs.