Are surge arresters required by the NEC for systems over 1,000 volts?

Surge arresters are not explicitly required by the National Electrical Code (NEC) for systems operating over 1,000 volts. The NEC provides guidelines intended for electrical safety and protection but does not mandate that surge protection devices must be installed for all high-voltage systems. The decision to install surge arresters can depend on various factors, such as the specific risk of transient overvoltages in that area, the importance of the equipment being protected, and whether other standards or local regulations necessitate their use.

In many instances, surge protection is considered best practice, especially in sensitive or critical applications, but the NEC does not impose a blanket requirement for installation at those voltage levels. It is essential, however, to consult local codes or protective measures tailored to specific installations, as some jurisdictions might have additional requirements beyond what the NEC outlines.