Saving those ‘magic moments’
The role of reclosers in power supply networks
It’s easy to take electrical power for granted. With what must seem like magic, it flows into homes and businesses and consumers live in the comfort that comes from knowledge that energy is available at the touch of a button.
But those of us who work in the business of power supply know the many challenges of delivering electricity, from generation through transmission and finally to domestic and commercial supply. One aspect often taken for granted is quick recovery from faults on the line. Stretching for many miles, the risk of a sudden power outage on networks is always a concern, despite trimming of trees and protecting electrical components from wildlife. Faults do occur from time to time and without equipment like the modest recloser (as seen on telegraph poles across the developed world), outages on sections of the network would be much longer than they are today.
For consumers that could mean losing out on special moments: the TV cutting out during the penalty shoot-out, the computer failing just before printing a vital report or even just avoiding constant re-setting of clocks.
Reclosers have been around for decades, automatically returning power by closing power circuits which have been shorted out by a fault. Their benefits are two-fold: preventing transient short circuits from triggering prolonged power outages and restoring power without the need for a site visit.
ABB’s latest GridShield® outdoor vacuum reclosers use vacuum to insulate the gap between terminals. This replaces oil-filled alternatives and does not require regular oil testing and replacement.
Gridshield reclosers are used on three phase AC supplies and are designed to mechanically isolate each individual phase, so that a fault on one phase will not interrupt the supply on the other two. When tripped, the recloser springs into action, performing up to four automatic re-closes until the line is recovered. If this fails, a local control unit will feed data back to the control centre to let the system operators know that there is a sustained outage.
Central to the working of a recloser is its mechanical operation and like many things in life, the simpler the better. Gridshield reclosers are low maintenance and reliable. A magnetic actuator with only a single moving part means there’s less to go wrong. Designed for fast and frequent operation these reclosers are built for a lifetime of 10,000 operations and beyond.
The outdoor vacuum recloser is also environmentally friendly, with clean vacuum technology and high safety standards with no need for service engineers to access high voltage compartments during maintenance. They offer flexible options to meet customers’ requirements; and are competitive in terms of market presence.
ABB’s Griedshield outdoor vacuum recloser helps power utility engineers sleep soundly, in the knowledge that when needed it will act and electricity consumers will remain unaffected in the blissful ignorance of the faults that could otherwise have spoilt their magic moments.