Non-destructive condition monitoring of aged ethylene-propylene copolymer cable insulation samples using dielectric spectroscopy and NMR spectroscopy

2015 ◽  
Vol 46 ◽  
pp. 72-78 ◽  
Author(s):  
E. Linde ◽  
L. Verardi ◽  
P. Pourmand ◽  
D. Fabiani ◽  
U.W. Gedde
Author(s):  
Fabrice M. Guerout ◽  
Ladji Cisse ◽  
Richard Boor

The number of techniques available for on-site monitoring of low-voltage cables at nuclear plants is limited because of the requirement from station personnel to use non-destructive and non-intrusive techniques. This paper summarizes the results obtained to date using two new non-destructive methods. The first technique is based on the indentation of the cable insulation or cable jacket material and the study of post-indentation parameters to characterize the visco-elastic properties of the material tested. The novelty of the technique consists of measuring the time taken by the polymeric material to recover a set portion of the initial deformation and using this duration as a material degradation indicator. The technique can be used locally on the insulation of hook-up cables, on the insulation at the termination of jacketed cables, or directly on cable jackets. The second technique is based on the measurement of electrical dissipation factors (or tan delta) in the insulating material. A broadband frequency tan delta analyser was used to measure electrical dissipation factors at various frequencies, and identify the frequency ranges showing increased sensitivity to cable degradation. Specific electrodes and measurement methods were developed for practical on-site condition monitoring work. The measurement of electrical dissipation factors can be used to assess the local degradation of cable insulation in hook-up cables and global degradation of multi-pair conductor cables. When used on multi-pair conductor cables, the technique presents the advantage of providing a global indication of the cable condition.


2020 ◽  
Vol 184 ◽  
pp. 01059
Author(s):  
Ashish Khaira ◽  
Ravi. K. Dwivedi ◽  
Sanjay Jain

Markets are affected by assorted consumer requirements, which insist on superior quality, shorter delivery time, better customer support, and lower prices. Simultaneously, product life cycles are becoming shorter. Success relies on having either a cost-benefit or a value benefit, or, both in any competitive context. Therefore, non-destructive techniques (NDT) become vital but in the conventional system, the maintenance personnel has to visit the machine that consumes time and energy. In the present COVID-19 situation and to save energy and time, there is a necessity of making condition monitoring contactless as much as possible. Therefore, in this research work, a structural health monitoring analysis presented that covers: firstly, enlisting of the NDT infrastructure commonly available in heavy manufacturing industries; secondly, common causes and reasons of machine failures and finally, discusses need of embedded structural health monitoring (e-SHM) system with the combination of NDT in place of existing monitoring practice. The presented work suggested that a combination of NDT with e-SHM is better for timely fault detection to ensure effective condition monitoring.


2015 ◽  
Vol 15 (3) ◽  
pp. 430-435
Author(s):  
Shivanandan S. Indimath ◽  
Souvik Das ◽  
Goutam Mukhopadyay ◽  
Sandip Bhattacharyya

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