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Past Experience at Canadian Utility with Surge Arresters on Transmission Lines

July 22, 2017 • Arresters, ARTICLE ARCHIVE, Utility Practice & Experience
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Problems with Line Arresters

NB Power’s history with transmission line arresters began in October 2001. Over the following years, a number of manufacturing defects as well as installation problems were experienced. It was also observed that hardware components supplied with the arrester are showed premature signs of wear.

The following photos illustrate examples of arrester problems experienced.

Figure 5: Example of manufacturing defect. 69 kV arresters with poor crimp on lug allowing strands to pull out. arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines fig8

Fig. 5: Example of manufacturing defect. 69 kV arresters with poor crimp on lug allowed strands to pull out.

Figure 6: Problem due to improper installation. 69 kV disconnector broke because lead was too tight arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines fig6

Fig. 6: Problem due to improper installation. 69 kV disconnector broke because lead was too tight.

 

 

 

 

 

 

 

 

 

 

 

Fig. 7: Example of manufacturing defect causing inadequate moisture seal on weathershed end cap. Two units failed, resulting in line outages. arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines Screen Shot 2017 07 21 at 14

Fig. 7: Example of manufacturing defect causing inadequate moisture seal on weathershed end cap. Two units failed, resulting in line outages.
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Fig. 8: 138 kV split in weathershed from internal tracking due to moisture ingress through end cap. Thermovision inspection recommended arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines Screen Shot 2017 07 21 at 13

Fig. 8: 138 kV split in weathershed from internal tracking due to moisture ingress through end cap.
Thermovision inspection recommended.
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Fig. 7: Example of manufacturing defect causing inadequate moisture seal on weathershed end cap. Two units failed, resulting in line outages. arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines Screen Shot 2017 07 21 at 14

Fig. 9: 69 kV inferior lugs broke while in service.
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Fig. 10A: 138 kV lead and chain worn out after only 6 years’ service. arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines Screen Shot 2017 07 21 at 14

Fig. 10A: 138 kV lead and chain worn out after only 6 years’ service.
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Fig. 9: 69 kV inferior lugs broke while in service arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines Screen Shot 2017 07 21 at 14

Fig. 10B: 138 kV close-up of chain link.
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Fig. 11: 138 kV lead broken away from lug. Problem still being investigated. arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines Screen Shot 2017 07 21 at 14

Fig. 11: 138 kV lead broken away from lug.
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As part of its program of installing transmission line arresters, NB Power purchased these components from three different manufacturers and experienced hardware problems with each of them (see Table 2). In addition to the problems noted above there have also been other hardware problems such as suspension eyelets breaking and a failed pipe clamp on a dead-end insulator/arrester assembly.

Summary of Experience with Defective Arresters arresters Past Experience at Canadian Utility with Surge Arresters on Transmission Lines table2

Table 2: Summary of Experience with Defective Arresters.
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