In what situations is underground wiring permitted according to NEC?

Underground wiring is permitted under the National Electrical Code (NEC) when it is properly installed and protects against moisture and physical damage. This requirement emphasizes the importance of safeguarding electrical installations in underground settings, as these cables must withstand exposure to soil moisture, potential physical pressure from above, and other environmental factors.

When installed according to NEC guidelines, underground wiring can include the use of specific types of cable rated for burial, such as UF (Underground Feeder) cable or other approved methods. These cables are designed with insulation and shielding that provide necessary protection, making them suitable for direct burial or placement in conduits that are suitable for underground use.

This option underscores not only the permissibility of underground wiring but also the strict adherence to safety standards that must be followed to ensure reliable and safe electrical systems in varied environments.