Ac voltage phase discriminator for circuit breaker locators
AssigneeFluke Corporation
InventorMichael F. Gallavan
Life of this patent
Estimating the term…
Abstract
An arrangement that includes a transmitter unit and a receiver for locating a circuit interrupter associated with a selected branch circuit of a power distribution system. The transmitter is electrically interconnected with the selected branch circuit and produces a sequence of tracing signals in a branch circuit that is to be traced. Each tracing signal is transmitted and detected at times measured with respect to a detected known phase of the signal on the branch circuit. In one embodiment, tracing signals are transmitted on a branch circuit of a 3 phase power distribution system when the branch circuit to be tested has a positive phase and the other phases are negative.
Claims17
A circuit for inducing tracing signals into a branch circuit having an associated circuit interrupter, comprising:
- a controllable circuit for inducing one or more tracing signals in the branch circuit;
- a phase detector circuit for detecting a known phase point of a signal on the branch circuit;
- and
- a controller that causes the controllable circuit to induce the one or more tracing signals in the branch circuit at predefined times that are measured with respect to the detected known phase point.
A receiver for indicating a circuit interrupter associated with a branch circuit into which a one or more tracing signals have been induced, comprising:
- a pick up coil for generating signals indicative of a tracing signal induced in a branch circuit;
- a phase detector circuit for detecting a known phase point on the branch circuit;
- a microprocessor that is programmed to analyze the signals produced by the pick up coil during a window of time that is measured with respect to the detected known phase point on the branch circuit in order to detect a tracing signal induced into the branch circuit;
- and
- a human perceptible indicator controlled by the microprocessor to alert a user that the receiver is in proximity to a circuit interrupter associated with the branch circuit if at least one tracing signal is detected during the window of time.
A system for detecting tracing signals induced onto a particular branch circuit, comprising:
- switch means for inducing one or more tracing signals into a branch circuit;
- control means that causes the switch means to induce the one or more tracing signals into the branch circuit at predefined times measured with respect to a detected known phase point of the signals on the branch circuit;
- and
- probe means for detecting one or more induced tracing signals at a circuit interrupter during one or more time widows that are measured with respect to a detected phase point of a branch circuit in proximity with the probe means and for alerting a user when the probe means is in proximity to the branch circuit in which one or more tracing signals are induced if the one or more tracing signals are detected during the one or more time windows.
Dependencies are inferred from the claim text.