Motor relay with integrated arc-flash detection

Patent metadata

Field	Value
Publication number	US-9438028-B2
Application number	US-201213600727-A
Country	US
Kind code	B2
Filing date	Aug 31, 2012
Priority date	Aug 31, 2012
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

Disclosed herein are various embodiments of devices and related methods for detecting an electrical arc event using a motor management relay and for suppressing the electrical arc event. The motor management relay may incorporate an optical arc-flash sensor configured to detect an optical event. Control logic may analyze the optical event and determine whether the optical event corresponds to an electrical arc event. When an electrical arc event is detected an instruction may be issued via a control port in communication with the control logic to implement a protective action. According to various embodiments, a plurality of sensors for monitoring electrical characteristics of a motor may also be in communication with the control logic. Input from the sensors may be analyzed in order to determine whether the optical event corresponds to an electrical arc event.

First claim

What is claimed is:

1. A motor management relay, comprising:
a plurality of current sensors configured to monitor the flow of electrical current to a motor;
a housing comprising a plurality of apertures, each aperture of the plurality of apertures is associated with at least one of the plurality of current sensors, the plurality of current sensors integrated within the housing, wherein conductors conducting the electrical current to the motor pass through the plurality of apertures and the plurality of current sensors;
an optical arc-flash sensor integrated within the housing of the motor management relay, configured to detect an optical event;
control logic integrated within the housing and configured to analyze the optical event and determine whether the optical event corresponds to an electrical arc event; and
a control port integrated within the housing and in communication with the control logic, the control port configured to issue an instruction to an associated protective device to implement a protective action based on a determination that the optical event corresponds to an electrical arc event;
wherein the housing comprises a form factor for installation of the motor management relay in one of a motor control center bucket and an International Electrotechnical Commission drawer.

2. The motor management relay of claim 1 , wherein the optical arc-flash sensor comprises a two-axis sensor.

3. The motor management relay of claim 1 , wherein the housing comprises two sides, and, wherein the arc-flash sensor is disposed with respect to the housing such that the arc-flash sensor is at least partially disposed on the two sides of the housing.

4. The motor management relay of claim 1 , further comprising a plurality of status indicators disposed on the housing.

5. The motor management relay of claim 1 , further comprising a zero sequence current sensor configured to monitor electrical characteristics.

6. The motor management relay of claim 1 , wherein the control port is configured to selectively actuate one of a contactor and a breaker.

7. The motor management relay of claim 1 , further comprising a human-machine interface port.

8. The motor management relay of claim 7 , wherein upon the detection of an electrical arcing event, a signal is sent to the human-machine interface port.

9. The motor management relay of claim 1 , wherein the control logic is configured to analyze a duration of the optical event to determine whether the optical event corresponds to an electrical arc event.

10. The motor management relay of claim 1 , wherein the control logic is configured to analyze an intensity of the optical event in order to determine whether the optical even corresponds to an electrical arc event.

11. The motor management relay of claim 1 , further comprising an input port configured to receive input from an external arc flash sensor.

12. A method of detecting an electrical fault associated with an electrical motor, the method comprising:
monitoring a flow of electrical current supplied to a motor with a motor management relay, wherein the flow of electrical current is monitored using current sensors that are integrated within a housing of the motor management relay, and wherein conductors carrying the electrical current pass through apertures in the housing of the motor management relay and through the current sensors to integrated within the housing of the motor management relay;
detecting an optical event indicative of an arc flash associated with an electrical arc using an optical sensor disposed on the housing of the motor management relay;
analyzing the optical event using control logic integrated within the housing;
determining that corrective action is required based on the optical event using the control logic;
generating a control signal using the control logic in the motor management relay to implement corrective action; and
issuing an instruction using a control port integrated within the housing an associated protective device to implement a protective action based on a determination that the optical event corresponds to an electrical arc event;
wherein the housing comprises a form factor for installation of the motor management relay in one of a motor control center bucket and an International Electrotechnical Commission drawer.

13. The method of claim 12 , further comprising:
comparing the electrical current supplied to the motor to a specified parameter using control logic in the motor management relay; and
wherein determining that corrective action is required is further based upon the comparison of the electrical current supplied to the motor and the specified parameter.

14. The method of claim 13 , further comprising
generating an indication of the optical event upon the comparison of the electrical current supplied to the motor and the specified parameter;
communicating the indication of the optical event to a distributed control system.

15. The method of claim 12 , wherein the corrective action comprises an instruction to interrupt the flow of electrical current supplied to the motor.

16. The method of claim 12 , further comprising
generating an indication of the optical event;
communicating the indication of the optical event to a distributed control system.

Assignees

• D'Aversa Angelo
• Kesler James R
• Jayne Robert I
• Schweitzer Engineering Lab Inc

Inventors

• D'Aversa Angelo
• Kesler James R
• Jayne Robert I

Classifications

• H01H71/12

  Automatic release mechanisms with or without manual release · CPC title

• H02P29/60

  Controlling or determining the temperature of the motor or of the drive (H02P29/02 takes precedence) · CPC title

• H01H2083/201

  the other abnormal electrical condition being an arc fault · CPC title

• H01H83/00

  Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current · CPC title

• H02H5/042 Primary

  using temperature dependent resistors · CPC title