By contrast, the SVL model shown in Figure 6 has sheds similar to an arrester because it is intended for outdoor application.įig. In Figure 5, the arrester has no sheds because this particular design is intended only for use in the dry environment of a link box. Two examples of sheath voltage limiters are shown in Figures 5 and 6. It functions as surge arrester and, in most cases, is in fact a re-labelled distribution arrester. The SVLĪ sheath voltage limiter (SVL) is basically a surge arrester under a different terminology. The phase conductors do not enter the link box, rather only the sheath or sheath extension. The link box in this case is a universally used sealed junction box placed either in manholes or cabinets and that accommodates surge protectors as well as a point to cross-bond the sheaths.įigure 4shows a typical such link box setup that provides a location for the sheath voltage limiters as well as for cross bonding of the sheath. While a range of configurations is used to reduce losses in cable systems, (including cross-bonding of the sheaths and transposing phase conductors) segmentation along with surge protection of the cable jacket is considered the most effective. 4Link box with 3 SVLs and cross-bonded sheaths Since high voltage cables these days are available in an array of different types and designs, for the sake of simplicity the focus here was on a single core HV cable with metallic sheath and polymeric outer sheath jacket (as in Fig. This article from 2012 contributed by surge arrester expert and INMR Columnist, Jonathan Woodworth, explained the surge protection scheme offered by sheath voltage limiters (SVLs) – devices intended to protect the cable jacket or cable sheath from electrical stresses during transient events. Together, these developments have sharply accelerated application of surge protection on underground cable networks. They are highly reliable and effective at managing cable sheath voltage rises and the associated power flows that can result under fault conditions.Īt the same time, ensuring high reliability of these lines is progressively more important. Sheath Voltage Limiters also known as SVL’sprovide valuable protection to expensive cable installations. Over the past decade, demand for longer power lines and higher current capacities for HV High Voltage power cables has required new methods of loss prevention. SVL’s Sheath Voltage Limiters for Protection of MV HV Cables Protecting the Cable Sheath & Jacket from Switching Surge
0 kommentar(er)
