IN-CABINET THERMAL MONITORING METHOD AND SYSTEM

• US 20100044567A1
• Filed: 08/21/2008
• Published: 02/25/2010
• Est. Priority Date: 08/21/2008
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Inventors: Brandt, David D., Jensen, David L.
• Granted Patent: US 7,989,769 B2
• Time in Patent Office: Days
• US Class Current: 250/334
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01J 5/0096 for measuring wires, electrical contacts or electronic systems
• CPC Class Codes: G01J 5/02 Constructional details
• CPC Class Codes: G01J 5/026 Control of working procedures of a pyrometer, other than calibration; Bandwidth calculation; Gain control
• CPC Class Codes: G01J 5/04 Casings
• CPC Class Codes: G01J 5/047 Mobile mounting; Scanning arrangements
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0804 Shutters
• CPC Class Codes: G01J 5/0846 having multiple detectors for performing different types of detection, e.g. using radiometry and reflectometry channels
• CPC Class Codes: G01J 5/48 Thermography; Techniques using wholly visual means
• CPC Class Codes: H02B 1/306 Accessories, e.g. windows
• CPC Class Codes: H02B 1/38 Hinged covers or doors
• CPC Class Codes: H02B 13/025 Safety arrangements, e.g. in case of excessive pressure or fire due to electrical defect

Abstract

Thermographic imaging equipment is incorporated directly into cabinets housing electrical switchgear to provide for dedicated, nearly continuous monitoring of the contained equipment. A mechanical scanning technique may allow low-cost sensors to provide essentially continuous thermographic monitoring. Dedicated thermal imaging equipment allows automatic analysis through predefined temperature threshold maps.

Claims

1. An electrical component cabinet comprising:

a housing providing fire resistant walls enclosing a housing volume;

at least one internal component mounting panel within the housing volume for an attachment of electrical components thereto;

a thermographic camera attached to a housing wall opposite the mounting panel for imaging electrical components attached to the mounting panel, the thermographic camera sensitive in a light frequency of 3-15 μ

m;

a remote monitoring station; and

an electrical connection between a thermographic camera and the remote monitoring station relaying thermographic images of components attached to the internal component mounting panel to the remote monitoring station for monitoring thereof.

2. The electrical component cabinet of claim 1 wherein the thermographic camera provides a mechanically scanned thermally sensing element.

3. The electrical component cabinet of claim 2 wherein the mechanical scanning provides a mirror system scanning the mounting panel;

4. The electrical component cabinet of claim 2 wherein the mechanical scanning provides a track for moving the thermally sensing element.

5. The electrical component cabinet of claim 4 wherein one housing wall provides an access door and the track includes two vertical rails flanking the door and a horizontally extending carriage moving along the vertical rails and supporting the thermally sensing element for movement therealong, and

further including a camera parking system for moving the carriage to an extreme point on the track when the door is opened.

6. The electrical component cabinet of claim 2 wherein the thermally sensing element is a pyroelectric element.

7. The electrical component cabinet of claim 1 wherein the mounting panel is on a wall of the housing opposite a door providing access to the housing and wherein the thermographic camera is attached to an inner surface of the door.

8. The electrical component cabinet of claim 1 wherein the electrical connection is a network connection.

9. The electrical component cabinet of claim 1 wherein the electrical connection is a radio transceiver system.

10. The electrical component cabinet of claim 1 wherein the remote monitoring evaluates received thermographic images on a predetermined schedule to provide an alarm if a predetermined temperature threshold is exceeded.

11. The electrical component cabinet of claim 1 wherein the remote monitoring station provides at least one mask corresponding to a thermographic image from the thermographic camera, the mask providing temperature thresholds for different mask regions;

and

wherein the remote monitoring station automatically compares temperatures of the thermographic image within the different mask regions to the temperature thresholds associated with the masked regions to generate an alarm when the temperature thresholds are exceeded for a given mask region.

12. The electrical component cabinet of claim 11 wherein the remote monitoring station further communicates with a controller activating electrical components mounted to the mounting panel in a series of control states, and

wherein the remote monitoring station selects among different masks corresponding to different control states for a generation of the alarm.

13. The electrical component cabinet of claim 1 wherein the remote monitoring station monitors successive thermographic images to detect degradation associated with dirt accumulating on optics of the thermographic camera to generate an alarm when the degradation exceeds a predetermined threshold.

14. The electrical component cabinet of claim 1 further including electrical components attached to the mounting panel selected from the group consisting of:

circuit breakers, disconnects, contactors, overload relays, switches, and motor starters.

15. A thermographic monitoring system comprising:

a thermographic camera providing a means for attachment of the thermographic camera to an interior wall of an electrical cabinet for imaging a mounting panel within the electrical cabinet having electrical components attached thereto, the thermographic camera providing a mechanically scanned thermally sensing element;

a remote monitoring station communicating with the thermographic camera for receiving from the thermographic camera thermographic images of electrical components attached to the mounting panel,

wherein the remote monitoring station provides at least one mask corresponding to a thermographic image from the thermographic camera, the mask providing temperature thresholds for different mask regions; and

wherein the remote monitoring station automatically compares temperatures of the thermographic image within the different mask regions to the temperature thresholds associated with the mask regions to generate an alarm when the temperature thresholds are exceeded for a given mask region.

16. The thermographic monitoring system of claim 15 wherein the remote monitoring station further communicates with a controller activating electrical components mounted to the mounting panel in a series of control states, and

wherein the remote monitoring station selects among different masks corresponding to different control states for the generation of the alarm.

17. The thermographic monitoring system of claim 15 wherein the remote monitoring station monitors successive thermographic images to detect degradation associated with dirt accumulating on optics of the thermographic camera to generate an alarm when the degradation exceeds a predetermined threshold.

18. The thermographic monitoring system of claim 17 wherein the detected degradation is a decrease in thermographic contrast.

19. An electrical components cabinet comprising:

a housing providing fire resistant walls enclosing a housing volume;

at least one internal component mounting panel within the housing volume;

electrical components attached to the mounting panel and selected from the group consisting of;

circuit breakers, disconnects, contactors, overload relays, switches, and motor starters;

a thermographic camera attached to a housing wall opposite the mounting panel for imaging electrical components attached to the mounting panel, the thermographic camera sensitive in an infrared region of 3-15 μ

m;

a remote monitoring station; and

an electrical connection between a thermographic camera and the remote monitoring station relaying thermographic images of components attached to the internal component mounting panel to the remote monitoring station for monitoring thereof,

wherein the remote monitoring station provides substantially continuous thermal monitoring of multiple points electrical components.