In what scenario should a disconnecting means be provided for ungrounded conductors?

A disconnecting means for ungrounded conductors is essential when the conductors supply or pass through a building. This requirement ensures that safe maintenance and emergency procedures can be followed, allowing personnel to disconnect power effectively before working on or around the electrical system. Having a disconnecting means in such locations provides a clear and accessible method for ensuring safety, as it allows workers to fully de-energize circuits that could pose a hazard during maintenance or repair.

The National Electrical Code (NEC) emphasizes the significance of being able to quickly disconnect power to prevent possible electrical hazards. When conductors run through or supply energy to a building, the potential for access to and interaction with those conductors increases, necessitating a reliable way to disconnect power.

In scenarios where conductors are located indoors or protected by fuses, or when supplying a critical load, specific code provisions may guide practices, but the primary safety concern is ensuring that any conductors passing through or supplying power to a building have a clear disconnecting means to enhance safety. This preventive measure is vital in managing electrical risks effectively.