Power losses – also known as faults – can affect hundreds of homes and businesses on a particular circuit (a path or line through which an electrical current flows). Usually caused by tree limbs, animals coming into contact with powerlines or lightning strikes, most of these outages are momentary and last less than a minute. But the off-and-on “blinking” that occurs in homes disrupts lighting, cable and satellite TV boxes, computers and digital clocks.
Tested for more than a year in a service area of 2,243 customers in St. Cloud (the worst-performing circuit in our grid), the TripSaver® II Cutout Mounted Recloser proved to be so effective that OUC recently added the device to two troublesome circuits in Orlando and plans to use it in other locations as well.
“On average over a three-year period, 1,397 customers per year experienced outages on the circuit in St. Cloud,” said Melvin Liwag, Senior Engineer, Operations, who led the project. “OUC was committed to resolving the issue, so in March 2018 we began testing 75 TripSavers on smaller power lines that carry electricity from main power lines to your neighborhood. The devices reduced the number of customers experiencing permanent outages by 81%, and this success rate led us to expand installations.”
TripSaver, Liwag explained, limits the frequency and duration of service disruptions. The device acts like a home circuit breaker, tripping when there’s a sudden interruption in the flow of power. If the cause of the fault is only temporary, such as a tree branch brushing over a power line, the device restores service almost instantly. But in a more serious situation, such as fallen tree resting on a power line, the device determines the outage is permanent and contains it to only a portion of the circuit.
In the St. Cloud pilot, the number of momentary power interruptions improved by 54% – and the total customer minutes of interruption (CMI), a key metric of reliability, improved nearly 81% for 2015-2017.
OUC recently installed 50 devices on circuits serving customers in College Park and Delaney Park and continues to refine the process. Liwag said OUC has learned a lot from the three installations and “going forward, we will change our approach on how we install TripSavers® and gather data from them for optimum efficiency.”
Keith Mutters, OUC’s Director of System Planning and Reliability Engineering, added: “Melvin and the entire project team did a fantastic job with the St. Cloud pilot project. The technology has now been incorporated into our system protection design and our line technicians are fully trained in the safe operation of the devices. Based on the pilot results, we have begun a five-year program to install around 1,200 across the system.”