What is the impact of the NEC Short Circuit Current rating?
Under Article 285, Section 6 of the NEC – Short Circuit Current Rating, the TVSS shall be marked with a short circuit current rating and shall not be installed at a point on the system where the available fault current is in excess of that rating. It is a requirement of the NEC that the available fault current at the installation does not exceed the available shortcircuit rating of the TVSS device. This coordination can be achieved in two ways: The TVSS device has a short-circuit rating that meets or exceeds the available fault current at the installation, or Provide a current limiting device (typically circuit breaker or fuse) to limit the short-circuit current exposure of the TVSS device to a level that is below its short-circuit current rating.
Under Article 285, Section 6 of the NEC – Short Circuit Current Rating, “the TVSS shall be marked with a short circuit current rating and shall not be installed at a point on the system where the available fault current is in excess of that rating.” It is a requirement of the NEC that the available fault current at the installation does not exceed the available shortcircuit rating of the TVSS device. This coordination can be achieved in two ways: • The TVSS device has a short-circuit rating that meets or exceeds the available fault current at the installation, or • Provide a current limiting device (typically circuit breaker or fuse) to limit the short-circuit current exposure of the TVSS device to a level that is below its short-circuit current rating.
