Hardware Based Over-Current Protection Circuitry for Power Distribution Systems

• US 20100085674A1
• Filed: 12/08/2009
• Published: 04/08/2010
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Vertiv IT Systems, Inc. (Vertiv Holdings Co.)
• Original Assignee: Avocent Huntsville, LLC (Vertiv Holdings Co.)
• Inventors: Martins, Carlos E.
• Granted Patent: US 9,722,412 B2
• Time in Patent Office: Days
• US Class Current: 361/93.100
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: H02H 3/027 with automatic disconnection after a predetermined time H02H3/033, H02H3/06 take precedence ; timing in overcurrent protection circuits H02H3/093; in undervoltage protection circuits H02H3/247; staggered disconnection H02H7/30
• CPC Class Codes: H02H 3/063 Details concerning the co-operation of many similar arrangements, e.g. in a network sectionalised protection H02H7/26
• CPC Class Codes: H02H 3/093 with timing means in general H02H3/027; thermal delay H02H3/085; timing means for undervoltage protection H02H3/247

Abstract

A power distribution unit that switches off power outlets in the event of an over-current condition by using circuitry that measures how long input current has exceeded a threshold and sending a reset signal to the power outlets when input current has exceeded the threshold for a predetermined time duration.

Claims

1. A power distribution unit comprising:

a plurality of switched power outlets adapted to provide power to external devices wherein the switched power outlets are adapted to be controlled by a control signal;

a sensor that measures the magnitude of the current of power being drawn by the power distribution unit;

a comparator that determines if the magnitude of the current exceeds a predetermined threshold;

time qualification circuitry that determines if the magnitude of the current exceeds the predetermined threshold for a predetermined time duration; and

control circuitry that sends a control signal to said switched power outlets when the magnitude of the current exceeds a predetermined threshold for a predetermined time duration.

2. The power distribution unit of claim 1, wherein said control signal opens said switched power outlets thereby preventing power from being provided to said external devices.

3. The power distribution unit of claim 2, wherein said control circuitry sends said control signal until a predetermined event occurs.

4. The power distribution unit of claim 3, wherein said power distribution unit is configured such that said predetermined event is receiving a reset command from a remote user via a network.

5. The power distribution unit of claim 1, wherein said predetermined thresholds are electronically programmable.

6. A method for determining when an over-current condition occurs in a power distribution unit comprising the steps of:

measuring the magnitude of current of power drawn by the power distribution unit;

determining if the magnitude of the current exceeds a predetermined threshold;

determining if the magnitude of the current exceeds the predetermined threshold for a predetermined time duration;

indicating that the magnitude of the current has exceeded a predetermined threshold for the predetermined time duration;

sending a control signal preventing power distribution unit from distributing power.

7. The method of claim 6, further comprising the steps of:

storing an indication that an over-current condition has occurred until a predetermined event occurs.

8. The method of claim 7, wherein said predetermined event is receiving a control signal from a remote user via a network.

9. A power distribution unit comprising:

a plurality of switched power outlets adapted to provide power to external devices wherein the switched power outlets are adapted to be controlled by a control signal;

sensor circuitry that measures the magnitude of the current of power being drawn by each of said plurality of switched power outlets;

comparator circuitry that determines for each of said plurality of switched power outlets if the magnitude of the current exceeds a predetermined threshold;

time qualification circuitry that determines for each of said plurality of switched power outlets if the magnitude of the current exceeds the predetermined threshold for a predetermined time duration;

control circuitry that sends a control signal to a subset of said plurality of switched power outlets if the magnitude of the current of the switched power outlet exceeds a predetermined threshold for a predetermined time duration.

10. The power distribution unit of claim 9, wherein said control signal opens said switched power outlet thereby preventing power from being provided to said external devices.

11. The power distribution unit of claim 10, wherein said control circuitry sends said control signal to a switched power outlet until a predetermined event occurs.

12. The power distribution unit of claim 11, wherein said power distribution unit is configured such that said predetermined event is receiving a reset command from a remote user via a network.

13. The power distribution unit of claim 9, wherein said predetermined thresholds are electronically programmable.