Where have bushings been installed on conduits entering a box according to the NEC®?

Bushings are protective devices used at the ends of conduits to prevent fraying or damage to the conductors when they enter terminal boxes, junction boxes, or enclosures. According to the National Electrical Code (NEC®), all conduits that enter a box should have bushings installed to ensure that the edges of the conduit do not damage the insulation of the wires or cables within them.

The correct choice indicates that bushings should be installed on all conduits entering a box. This practice enhances safety by minimizing risks such as short circuits or insulation failure due to a lack of protection at the conduit entries. Proper installation of bushings on all conduits is a critical safeguard in electrical installation practices, addressing both mechanical protection and electrical integrity.