Innovative Overhead Fault Monitoring Solution Boosts Reliability

A state-of-the-art overhead fault monitoring device rolled out by Chicago-based S&C Electric looks like a great solution for mitigating nuisance power outages for customers located on the edge of the grid.  The device, called the VacuFuse II Self-Resetting Interrupter, is designed to determine if an overhead fault is temporary, and if so, can automatically mitigate the issue to restore power.

How the S&C Overhead Fault Monitoring Solution Can Improve Reliability

According to S&C, most faults are temporary in nature, and therefore an effective method to reduce their impact is to use fault-testing devices to keep these temporary issues from becoming permanent outages.

While there is a plethora of fault-testing devices in use today, they are usually installed on the main feeder.  Conversely, the VacuFuse solution, which works with overhead transformers from 7.2 kV to 12.5 kW and is available in sizes compatible with 15-kV and 25-kV cutouts to accommodate most lateral systems, can be deployed in a more diversified manner to provide fortification all the way to the edge of the service territory.  This is critical because research has shown that up to 70% of faults at the edge of the grid are temporary in nature, caused by factors like animal activity or falling tree branches, yet these issues often take hours to resolve using traditional methods.

With this system, the fault can be mitigated quickly, eliminating the need to send a crew.  In addition, the system allows utilities to specifically target edge-of-grid areas that have proved problematic historically.  The result is likely to be reduced O&M costs and greater customer satisfaction.

So, how does it work?  Well, whenever the device detects a fault current, the device’s vacuum interrupter opens and disrupts the current.  The device then tests the line about 45 seconds later to see if the fault remains.  If it doesn’t, the vacuum interrupter closes, and the power is automatically restored.  If the fault does remain, the vacuum interrupter remains open and leaves a signal to direct the utility to the exact location of the needed repair.

All in all, anything that can reduce outages is a win in my book, and this overhead fault monitoring solution is certainly no exception.