PVC (Polyvinyl chloride) is widely used in electrical cable construction for insulation, bedding and sheathing. Cable with a PVC insulation or sheathing is flame retardant, which is an important consideration for electric cables in most applications. Multi-core mounting cables with polyvinylchloride insulation and sheath are designed for inter-device hardwiring of electric equipment operating at rated alternating voltage up to 500 V and 400 Hz frequency or direct voltage up to 750 V.