Circuit protector arc flash reduction system with parallel connected semiconductor switch

Patent metadata

Field	Value
Publication number	US-11749484-B2
Application number	US-202117480748-A
Country	US
Kind code	B2
Filing date	Sep 21, 2021
Priority date	May 10, 2018
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

An arc flash mitigation system includes a main circuit protector such as a high amperage overcurrent protection fuse, and an arc flash mitigation network connected in parallel to the main circuit protector. The arc flash mitigation network includes at least one semiconductor switch operable to provide a shunt current path to a low amperage arc mitigation fuse for a faster response time to certain circuit conditions than the main circuit protector otherwise provides. The semiconductor switch may be a silicon controller rectifier operatively responsive to a voltage drop across the main circuit protector in use.

First claim

What is claimed is:

1. An arc flash mitigation network for a main overcurrent circuit protector providing primary overcurrent protection to an electrical load, the arc flash mitigation network comprising:
first and second semiconductor switches connected in parallel to the main overcurrent circuit protector and an anti-parallel arrangement with one another; and
an arc mitigation fuse connected in series to the first and second semiconductor switches;
wherein an operation of at least one of the first and second semiconductor switches diverts current to the arc flash mitigation fuse in predetermined circuit conditions and wherein a prior opening of the arc mitigation fuse reduces arc flash energy in a subsequent opening of the main overcurrent circuit protector, thereby enhancing safety of personnel while servicing an energized electrical power system in the vicinity of the main overcurrent circuit protector.

2. The arc flash mitigation network of claim 1 , wherein the first and second semiconductor switches are connected in reverse polarity to one another.

3. The arc flash mitigation network of claim 2 , wherein the first and second semiconductor switches are operative with respect to an input to divert current to the arc mitigation fuse.

4. The arc flash mitigation network of claim 3 , wherein the input for each of the first and second semiconductor switches is a voltage across the main overcurrent circuit protector.

5. The arc flash mitigation network of claim 3 , wherein the first and second semiconductor switches are silicon controlled rectifiers.

6. The arc flash mitigation network of claim 2 , wherein the main overcurrent circuit protector is a main overcurrent protection fuse having a high amperage rating, and wherein the arc flash mitigation fuse has a low amperage rating.

7. The arc flash mitigation system of claim 6 , wherein the low amperage rating is one half or one third of the high amperage rating.

8. The arc flash mitigation system of claim 6 , wherein the high amperage rating is at least 300 A.

9. The arc flash mitigation system of claim 8 , wherein the high amperage rating is less than about 4000 A.

10. The arc flash mitigation system of claim 6 , wherein the main overcurrent protection fuse has a voltage rating of about 600 VAC.

11. The arc flash mitigation system of claim 6 , wherein the main overcurrent protection fuse has a voltage rating of about 300 VDC.

12. The arc flash mitigation system of claim 1 , wherein the main overcurrent protection fuse is larger than the arc flash mitigation fuse.

13. The arc flash mitigation system of claim 12 , wherein the main overcurrent protection fuse is configured to provide overload protection and short circuit protection.

14. The arc flash mitigation system of claim 13 , wherein the arc mitigation fuse is configured to provide short circuit protection only.

15. The arc flash mitigation fuse of claim 1 , wherein the main overcurrent protection fuse is a time delay fuse.

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Henricks Michael

Classifications

• H01H85/38 Primary

  Means for extinguishing or suppressing arc (by powder filling H01H85/18; by mechanical tension applied to fusible member H01H85/36) · CPC title

• H01H85/18

  Casing fillings, e.g. powder · CPC title

• H01H2085/383

  with insulating stationary parts · CPC title

• H01H85/12

  Two or more separate fusible members in parallel · CPC title

• H01H2009/546

  the static switching means being triggered by the voltage over the mechanical switch contacts · CPC title