NEMA規格 WC57, 2021: Standard for Control, Thermocouple Extension, and Instrumentation Cables
This standard applies to materials, construction, and testing of multiconductor control, thermocouple extension, and instrumentation cables rated up to and including 125°C. Control cables are multiconductor cables that convey electrical signals used for monitoring or controlling electrical power systems and their associated processes. Control cables convey signals between devices interfaced directly with the electrical power system, such as current transformers, potential transformers, relays, switches, and meters. Instrumentation cables and thermocouple extensions are multiconductor cables that convey lowenergy electrical signals (circuits that are inherently power limited) used for monitoring or controlling electrical power systems and their associated processes. Instrumentation cables and thermocouple extensions convey signals from process monitors to process analyzers (usually electronic equipment) and from the analyzers to control equipment in the electric power system. Construction details and test requirements for cables rated above 125°C can be found in the NEMA HP 100 series of standards.