What is the minimum trade size difference required for two conduits to be supported from one another according to the NEC®?

The National Electrical Code (NEC) specifies requirements for the support and installation of conduits to ensure safety and functionality in electrical systems. When it comes to supporting two conduits from one another, the NEC outlines a minimum size difference to ensure that the smaller conduit can be adequately supported by the larger conduit.

The correct answer is that a minimum trade size difference of 200% is required. This means that the larger conduit must be at least twice the size of the smaller conduit being supported. This requirement is put in place to prevent structural failure or damage due to inadequate support when multiple conduits are installed in close proximity.

This requirement reflects the practical need for ensuring adequate strength and stability in the installation of conduits, reducing the risk of electrical accidents or physical damage over time. Proper support enhances the longevity of the conduits and ensures that they fulfill their intended purpose without compromising safety compliance.