Middle East Query—Water-Block and Rejuvenation
Dweller of the Desert asked 22 questions in his post …
In this installment I address question 16.
16. What if my cable strands have water block design elements?
If a cable has thermoplastic strand fill material or has water absorption powder, it probably cannot be injected. However, these materials were not generally adopted until about 1985. It is unlikely that cables, which are suffering reliability issues, have strand-blocking features. When the Novinium process is used to inject cables, the Novinium Injection Adaptor is used to tenaciously seal the ends of the cable and each splice.
For those circuit owners that specify strand-blocked cable—stop! The cable manufacturers charge you more, but for what benefit? An understanding of how water distributes itself in a cable provides no justification for the additional expense. Click here to read an article in the November/December Issue of IEEE Electrical Insulation Magazine, “Molecular Thermodynamics of Water in Direct-buried Power Cables.” The “Molecular Thermodynamics” article provides data and a theoretical framework to understand the negative impact of stand-blocked conductor designs.
For now, Ma’a salama (معالسلامة/Good bye)
The messy polyisobutylene strand-blocking material provides a dubious benefit. If you use this stuff, I won’t be able to help you when your cable becomes unreliable.