A shielded cable has a built-in conductive layer that blocks EMI. A cable tray that isn't grounded properly can act as an antenna, amplifying EMI instead of reducing it. Unshielded cables are suitable for low electromagnetic frequency (EMF). The types of cables, allowed in cable trays, and the wiring methods permitted in cable trays can be found in NEC Section 392. This Section also lists various corresponding NEC Articles which describes the conditions of use, and installation requirements for a particular class or type of. An error occurred. WANT REELY GREAT DEALS? ©2026 Allied Wire & Cable, a GCG company. We compare and contrast shielded and unshielded tray cables to help you decided which is best for you next application. A common question arises: Can power cables and instrumentation/communication cables be run in the same cable tray? This article explores technical standards, safety considerations, and best practice. Technical Standards and Regulations NEC (National Electrical Code) Article 300.
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