The use of low-smoke halogen-free (LSZH) cables is on the rise, employing a more fire-resistant conduit material. As the name suggests, unlike traditional materials such as polyvinyl chloride (PVC) and fluorinated propylene rubber (FEP), LSZH cables produce less smoke and contain virtually no highly toxic gases known as halogens.
Given this, it seems logical that designers should always choose these cables. However, the actual decision-making process is far more complex, making it crucial for electrical engineers to understand LSZH cables, their applicable scenarios, and how to select and apply them.
LSZH cables are not suitable for all applications.
It's important to remember that while cables using halogenated compounds like PVC and FEP have been found to be hazardous in fires, LSZH cables are not a universal replacement for them for several reasons. First, PVC and FEP-based cables also have significant advantages that cannot be ignored. In open spaces where smoke and gases can spread rapidly, replacing them with LSZH cables offers little advantage. Furthermore, cables are typically not the only source of plastic in a fire, and PVC and FEP-based cables are fire-resistant, thus their responsibility for fires is relatively small compared to other factors.
PVC and FEP-based cables are more affordable than LSZH cables, offer excellent electrical performance, have a wide range of applications, and exhibit good electrical properties in both dry and humid environments. They also possess high flexibility, long service life, and can withstand extreme temperatures and chemicals, making them very robust and durable. In short, LSZH cables are best suited for situations where conventional cables may be hazardous. They are not intended to replace conventional cables in all applications.