Rigid PVC conduit larger than which trade size should not be used?

Rigid PVC conduit is widely used in electrical installations due to its durability, resistance to corrosion, and ease of handling. However, there are specific limitations regarding its use based on size. The standard guidelines establish that rigid PVC conduit larger than 6 inches in trade size is discouraged.

This is primarily due to several factors. One of the most significant is that as the diameter of the conduit increases, the structural strength and flexibility can decrease, making it less effective for supporting electrical conductors and enduring potential environmental stressors. Additionally, larger diameters can complicate installation and maintenance due to their weight and handling characteristics.

For conduits larger than this recommended size, other materials such as fiberglass reinforcements or different types of metals are often preferred, as they can better support larger installations without compromising the integrity of the system. This guidance helps ensure electrical systems are both safe and reliable while also facilitating proper installation practices.