Diagnostic wiring verification tester
AssigneeEaton Corporation
InventorRobert Tracy Elms
Life of this patent
Estimating the term…
Abstract
A tester for verifying the integrity of insulation in a branch circuit of a power distribution system. Two test circuits are included; the first providing an insulation test; and a second, a shared/grounded neutral test. In the insulation test, a 500-volt ac output limited to 5 milliamps is selectively applied to the pairs of wires of the branch circuit. If an output current of greater than 3 milliamps is recorded, an insulation failure is noted and the operator proceeds to the second test which applies a pulsed 3 volt, 1 ampere current-limited voltage across the suspected leads. One of the suspected leads is monitored with a portable ammeter to detect any pulse current.
Claims21
A tester for verifying the integrity of wiring insulation in an electrical circuit comprising:
- an alternating current voltage source having a first and second output terminal leads;
- a line lead wire connectable to a line conductor in said electrical circuit;
- a neutral lead wire connectable to a neutral conductor in said electrical circuit;
- a ground lead wire connectable to a ground conductor in said electrical circuit;
- a first switch connected to one of either the first or second voltage source output terminal leads and switchable between either said line lead wire or said neutral lead wire;
- a second switch connected to the other of either the first or second voltage source output terminal leads and switchable between either said neutral lead wire or said ground lead wire;
- and
- an ammeter connected in series with and between said voltage source and either said first or second switch.
A method of verifying the integrity of wiring insulation in an electrical circuit disconnected from a load, wherein the wiring includes at least line and neutral electrical conductors, comprising the steps of:
- isolating the electrical circuit from a main power supply;
- placing a preselected voltage across the line and neutral electrical conductors of the wiring, which is substantially larger than a voltage rating of the main power supply, but below a voltage rating of the wiring;
- and
- monitoring the leakage current flowing through the wiring to identify a predetermine leakage current indicative of failure of the wiring insulation.
Dependencies are inferred from the claim text.