Tips & News - January 2012

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technologies and work practices. We have just started installing electronic reclosers at circuit tie-points, where we used to install motorized air-break switches. In the event of a fault, a sectionalizing recloser lets us quickly break the feeder in two. We can then supply power from a different direction using the tie-point recloser, keeping some of our members in service while we fix the problem. This arrangement is great from a systems operation viewpoint because it gives us options, but it can create some minor problems in the field. Depending on fault location, we may not be able to use the tie-point recloser to isolate the fault. In the past, our reclosers were always attached to the primary line and opened by internal contacts only. But if we use them at tie-points, we need a way to isolate/by-pass the recloser—preferably in a way that does not entail removing the jumpers. Finding The Ideal Switch Assembly One of the first ideas was to build an isolation/by-pass assembly with nine of Hubbell’s solid blade, hook-stick switches: three to serve the left side of the pole, three to serve the right side of the pole and three to serve as the sectionalizer/by- pass switches. To install all of that, we would have to use two sets of double cross arms to mount the three on the left and the three on the right. And we would probably have to install another set of double cross arms to hang the other three switches underneath. This design would have required a substantial amount of labor and a total of nine hook-stick switches, driving the cost of the project for tie-points substantially higher. Then I remembered something I had seen at a conference a few years ago. Hubbell had a single-phase isolate/by-pass switch assembly that could be opened with a hookstick. I started envisioning how we could use those to improve our operation methods. Our operations manager

A few months ago, our only option would have been to send a crew in a bucket truck out there to manually remove the reclosers’ high-side jumpers. That would have taken some time to accomplish, delaying repairs and taking additional time to re-attach the jumpers when the repairs were complete. Today we are using Hubbell’s three-phase isolate/ by-pass switch: the BP3. In just seconds and without the need for a bucket truck, a lineman can isolate the line by opening the source and load switches that are part of the BP3 switch assembly. We just saved time and money. It also means we will get our members’ lights back on in a timely manner and do it without

compromising safety. Smart Grid Improvements

The Guadalupe Valley Electric Cooperative (GVEC) has about 68,000 customers in a service territory of 3,500 square miles in 13 counties in South Central Texas. We have about 7,900 miles of overhead distribution line. GVEC is in the early stages of applying Smart Grid

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