IEEE Std 532-2021 pdf download – IEEE Guide for Selectng and Testng Jackets for Power, Instrumentaton, and Control Cables.
1.4 General historical perspective Various compounded textile sandwich-type coatings were the predominant jackets used up to and into the 1950s. Experience has indicated that the electrical resistivity required to effectively isolate the metallic sheath or shield, or both, from their environment could not be satisfied by these jackets. In many situations, the dielectric integrity of the jacket is more important than the resistivity. Factors that infuenced improvement of jackets for cable sheaths/shields include the following: a) Consideration of the destructive effects of galvanic and electrolytic corrosion. b) The use of amphoteric metals (lead or aluminum) for cable sheaths, which are diffcult to protect cathodically. c) The use of metals (tinned copper, brass, or steel) to reinforce lead sheaths requiring a jacket that would reliably protect the pressure retaining metallic components from deterioration when placed in earth or ducts. d) The introduction of aluminum sheathed cables requiring a protective jacket of good mechanical and dielectric properties. e) The use of single conductor cable systems that, by their nature, involve induced voltages on the sheath/shield (see Eaton and Issa [B62]). It is desirable that the sheath/shield be isolated from its environment. 3 f) Practices to reduce electrical losses by minimizing circulating sheath/shield currents result in the appearance of voltages on the sheath/shield (see Halperin and Miller [B64], and Watson and Erven [B116]); under transient conditions, these voltages may be substantial.
4.3 Chemical and moisture resistance Jackets retard the ingress of water and environmental chemicals into the underlying core. Depending on the application, the properties of importance may include one or more of the following: — Resistance to high concentrations of organic and inorganic chemicals — Resistance to ozone concentrations higher than normally encountered in the atmosphere — Low moisture absorption — Oil resistance — Jackets over metallic shields, sheaths, and concentric neutral wires provide protection against corrosion and oxidation 4.4 Thermal stability The jackets are chosen for their thermal resistance and aging characteristics. Depending on the application, the properties of importance may include one or more of the following: — Physical stability over a range of temperatures from the minimum installation temperature to the maximum rated conductor temperatures (normal operating, emergency overload, and short-circuit). The actual jacket temperature with the conductor at these temperatures depends on the cable design and the installed environmental conditions.