Ground testing method and apparatus
First Claim
1. A ground-current isolating circuit for providing a low voltage barrier between a service neutral conductor and an associated grounding system of an electrical utility service, comprising:
- a first circuit arrangement to permit current in a first direction; and
a second circuit arrangement to permit current in a second direction opposite said first direction, each of said first and second circuit arrangements having a positive pole and a negative pole, and a characteristic threshold voltage for biasing at least one unidirectional element in each circuit arrangement to a conductive state, and current in a forward biased direction being blocked by the at least one element for forward biased voltages less than or equal to the threshold voltage;
wherein the first circuit arrangement positive pole is directly connected to the service neutral conductor and the first circuit arrangement negative pole is directly connected to the grounding system; and
the second circuit arrangement positive pole is directly connected to the grounding system; and
. the second circuit arrangement negative pole is directly connected to service neutral conductor.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention is directed to a ground-current isolating circuit for providing a low voltage barrier between a service neutral conductor and an associated grounding system. The voltage barrier circuit comprises a first current unidirectional element and a second current unidirectional element connected in antiparallel. The unidirectional elements are preferably diodes having a characteristic threshold voltage. The current in a forward biased direction is blocked by the circuit until an applied forward biased voltage exceeds the threshold voltage. The present invention also is directed to a method of isolating a neutral conductor temporarily from an associated grounding system during testing of a structure grounding system. The method includes connecting a voltage barrier circuit in parallel with a conductor bonding the neutral conductor to the associated grounding system, then disconnecting the bonding conductor; conducting a test of the structure grounding system associated with the structure, and reconnecting the bonding conductor between the neutral conductor and grounding system.
-
Citations
22 Claims
-
1. A ground-current isolating circuit for providing a low voltage barrier between a service neutral conductor and an associated grounding system of an electrical utility service, comprising:
- a first circuit arrangement to permit current in a first direction; and
a second circuit arrangement to permit current in a second direction opposite said first direction, each of said first and second circuit arrangements having a positive pole and a negative pole, and a characteristic threshold voltage for biasing at least one unidirectional element in each circuit arrangement to a conductive state, and current in a forward biased direction being blocked by the at least one element for forward biased voltages less than or equal to the threshold voltage;
wherein the first circuit arrangement positive pole is directly connected to the service neutral conductor and the first circuit arrangement negative pole is directly connected to the grounding system; and
the second circuit arrangement positive pole is directly connected to the grounding system; and
. the second circuit arrangement negative pole is directly connected to service neutral conductor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
- a first circuit arrangement to permit current in a first direction; and
-
19. (canceled)
-
20. (canceled)
-
21. (canceled)
-
22. (canceled)
Specification