For plastic trunking, PVC conduits are specified as major-responsibility and are not for use for set up in which the ambient temperature is above 60 levels Celsius or under minus 5 degrees Celsius. Metallic Trunking: Metallic Trunking is formed from mild metal sheet, coated with gray or silver enamel paint https://electricaltrunking89011.therainblog.com/35861416/the-greatest-guide-to-cable-trunking