Apparatus, system, and/or method for protection and control of an electrical device
AssigneeCerus Industrial Corporation
InventorsAndre Pierre Perra, Kent Jeffrey Holce, Roger Steven Cota
Life of this patent
Estimating the term…
Abstract
An electrical device protection apparatus, such as an overload relay, can include a microprocessor 102 that can receive a wide range of current signals from a current transformer or other current sensor. Also microprocessor 102 can employ a voltage sensor 112 to measure line voltage, for representing true power, and as a power supply 114 source for the microprocessor 102. The microprocessor can then generate annunciation signals 118, control signals 120, and/or communication signals 122 as necessary for the control and/or protection of an attached electrical device.
Claims36
An apparatus for providing overload thermal protection and control of a motor or electrical device having a motor, comprising:
- a current transformer provisioned for measuring power supply line current supplied to a motor or electrical device having a motor, with substantial accuracy over a wide current range;
- and
- a microprocessor configured for:
- receiving a current input signal corresponding to the power supply line current measured by the current transformer;
- receiving a voltage input signal corresponding to a voltage measured from the power supply line powering the motor or electrical device having a motor;
- identifying a classification of the motor or electrical device having a motor, and a corresponding overload thermal protection value, based, at least in part, on at least one of the received current input signal or the received voltage input signal;
- and
- implementing control logic to set a set point for operating the motor or electrical device having a motor consistent with the identified classification and corresponding overload thermal protection value.
A method, comprising the steps of:
- using a current transformer electromagnetically coupled to a power supply line, measuring at least one of an input signal or circuit characteristic of a power distribution circuit electromagnetically connected to a motor or electrical device having a motor;
- based at least in part on the measured input signal or circuit characteristic, classifying the motor or electrical device having a motor;
- and
- setting an overload thermal protection set point for the motor or electrical device having a motor based at least in part on the classification of the motor or electrical device having a motor.
The method of 25, further comprising the step of drawing operating power from a line power source supplying power to the power distribution circuit, the operating power being used for conducting the measuring, classifying, and setting steps.
A system for controlling and providing thermal protection for a motor or electrical device having a motor, comprising:
- a power supply line providing power to an a motor or electrical device having a motor;
- a contactor relay for disconnecting power supplied to the motor or electrical device having a motor, via the power supply line, in response to an undesirable operating condition being determined to exist in the motor or electrical device having a motor;
- and
- an overload protection relay including:
- a current transformer for measuring current supplied to the motor or electrical device having a motor via the power supply line;
- a microprocessor for identifying the motor or electrical device having a motor and setting one or more corresponding overload thermal protection set points to detect an occurrence of the undesirable operating condition in the motor or electrical device having a motor.
Dependencies are inferred from the claim text.