Live load indicator with door interlock

• US 10,123,436 B2
• Filed: 03/31/2014
• Issued: 11/06/2018
• Est. Priority Date: 03/31/2014
• Status: Active Grant

• Current Assignee: Schneider Electric USA, Inc. (Schneider Electric SE)
• Original Assignee: Schneider Electric USA, Inc. (Schneider Electric SE)
• Inventors: Rodriguez, Vladimir Cano, Najera, Gerardo Rodriguez
• Primary Examiner(s): Fleming, Fritz M
• Application Number:
  US15/129,530
• Publication Number:
  US 20170105299A1
• Time in Patent Office: 1,681 Days
• Field of Search: 307328
• CPC Class Codes: E05B 47/0603 the detent moving rectilinearly
• CPC Class Codes: E05B 65/00 Locks or fastenings for special use
• CPC Class Codes: G01R 19/15 Indicating the presence of current
• CPC Class Codes: G05B 9/02 electric
• CPC Class Codes: H02B 1/06 having associated enclosures, e.g. for preventing access to live parts
• CPC Class Codes: H05K 5/0017 with operator interface units
• CPC Class Codes: H05K 5/0208 Interlock mechanisms; Means for avoiding unauthorised use or function, e.g. tamperproof

Abstract

A monitoring system is provided for monitoring a status of current supply through a current supply conductor 5 in an electrical housing 1. A current transformer 13 and a monitoring circuit 15 monitor the conductor 5 in the housing 1. The monitoring circuit 15 is powered by current induced in the transformer from current in the conductor. The monitoring circuit 15 is configured to output a signal on an output line 14 indicating whether the current in the conductor is on or off. The monitoring circuit 15 is connected to at least one of a display device 24 and a door interlock 8 of a door of the housing 1 to, respectively, indicate whether the current in the conductor 5 is on or off and to prevent the door 17 of the housing 1 from opening when the signal on the output line 14 indicates that the current is on.

Claims

1. An electrical enclosure, comprising:

a housing structure containing a current supply conductor and at least one electrical device;

a current transformer surrounding the current supply conductor; and

a monitoring circuit electrically connected to the current transformer, the monitoring circuit'"'"'s operating power being provided by current induced in the current transformer from current in the current supply conductor, the monitoring circuit to use the operating power to monitor the current in the current supply conductor, the monitoring circuit to output a signal on an output line indicating whether current through the current supply conductor is on or off.

2. The electrical enclosure of claim 1, further comprising:

an access door mounted on the housing structure;

a door interlock mounted on the housing structure and located proximate to the access door of the housing structure, the door interlock being coupled to the output line from the monitoring circuit, the door interlock to prevent the access door from opening when the signal on the output line indicates that current through the current supply conductor is on.

3. The electrical enclosure of claim 2, wherein the monitoring circuit comprises an output of the induced current from the current transformer as the signal on the output line to provide operational power to the door interlock to prevent the access door from opening while there is current through the current supply conductor, and the signal does not provide operational power to the door interlock when there is no current through the current supply conductor, thereby unlocking the door.

4. The electrical enclosure of claim 2, further comprising:

an energy storage device in the monitoring circuit, the energy storage device to store energy from the current induced in the current transformer from current in the current supply conductor; and

the monitoring circuit further configured to provide operational power to the door interlock when current ceases to flow in the current supply conductor, thereby powering the door interlock to unlock the door.

5. The electrical enclosure of claim 1, further comprising:

a display mounted on the housing structure, the display being coupled to the output line from the monitoring circuit, the display to indicate whether current through the current supply conductor is on or off.

6. The electrical enclosure of claim 5, wherein the signal on the output line provides operational power to the display to indicate whether the current through the current supply conductor is on or off.

7. The electrical enclosure of claim 5, further comprising:

an energy storage device in the monitoring circuit, the energy storage device to store energy from the current induced in the current transformer from current in the current supply conductor; and

the monitoring circuit further configured to provide operational power to the display when current ceases to flow in the current supply conductor, thereby powering the display to indicate that current has ceased to flow in the current supply conductor.

8. The electrical enclosure of claim 5, further comprising:

an access door mounted on the housing structure;

a door interlock mounted on the housing structure and located proximate to the access door of the housing structure, the door interlock being coupled to the output line from the monitoring circuit, the door interlock to prevent the access door from opening when the signal on the output line indicates that current through the current supply conductor is on.

9. The electrical enclosure of claim 8, wherein the signal on the output line provides operational power to the door interlock to prevent the access door from opening while there is current through the current supply conductor, and the signal does not provide operational power to the door interlock when there is no current through the current supply conductor, thereby unlocking the door.

10. The electrical enclosure of claim 9, wherein the signal on the output line provides operational power to enable the display to indicate whether the current through the current supply conductor is on or off.

11. The electrical enclosure of claim 10, wherein the output line comprises a first output line that provides operational power to the door interlock and a second output line that indicates to the display a flow of current through the current supply conductor.

12. The electrical enclosure of claim 8, further comprising:

an energy storage device in the monitoring circuit, the energy storage device to store energy from the current induced in the current transformer; and

the monitoring circuit further configured to provide operational power to the door interlock when current ceases to flow in the current supply conductor, thereby powering the door interlock to unlock the door.

13. The electrical enclosure of claim 12, wherein the storage device is a capacitor.

14. The electrical enclosure of claim 5, wherein the display is a bistable display having a first stable state indicating that the current through the current supply conductor is on and a second stable state indicating that the current through the current supply conductor is off.

15. A live wire monitor, comprising:

a current transformer surrounding a current supply conductor to be monitored in an electrical enclosure;

a monitoring circuit electrically connected to the current transformer, the monitoring circuit'"'"'s operating power being provided by current induced in the current transformer from current in the current supply conductor, the monitoring circuit to use the operating power to monitor the current in the current supply conductor, the monitoring circuit to output a signal on an output line to at least one of a display device and a door interlock of a door of the electrical enclosure, indicating whether current through the current supply conductor is on or off.

16. The live wire monitor of claim 15, further comprising:

an energy storage device in the monitoring circuit, the energy storage device to store energy from the current induced in the current transformer from current in the current supply conductor; and

the monitoring circuit to output a portion of the energy stored in the energy storage device, to operate at least one of the door interlock on the electrical enclosure and the display device, when current through the current supply conductor is off.

17. The live wire monitor of claim 16, wherein the storage device is a capacitor.