You bring up a good point, and the answer lies in a combination of code requirements and best practices. Here's a breakdown

Code Requirement (NEC):
NEC 300.4(G) Protection From Abrasion

This section is the key. It states that where raceways (like your PVC conduit) enter enclosures or fittings, the conductors shall be protected from abrasion. This is the driving force behind needing something to protect the conductors.

Reaming is Required

The NEC (specifically 300.4(G)) requires you to ream the ends of the conduit to remove sharp edges or burrs. This is the first line of defense against abrasion.

The Question of Bushings



Reaming vs. Bushings

The NEC doesn't explicitly say you must use bushings in all situations where a conduit enters a box. A properly reamed conduit can satisfy the requirement of protecting against abrasion, especially with smaller conductors and properly sized conduit.

URD Wire & the Importance of Bushings

URD (Underground Residential Distribution) wire, while direct burial rated, can be relatively soft and easily damaged. Its insulation might be more susceptible to abrasion than some other types of building wire (like THHN/THWN). That's the important part.

Here's when bushings are generally considered necessary/recommended



Large Conductors

When pulling larger URD conductors (or any large conductor) through the conduit, the force and potential for abrasion against the conduit end increases dramatically.

Tight Bends Immediately After Entering the Box

If the conductors have to make a sharp bend immediately after exiting the conduit, the likelihood of abrasion is greater. A bushing helps to guide the conductors smoothly.

Conduit Misalignment

If the conduit entry is not perfectly aligned with the box knockout (creating an angle), a bushing can help prevent the conductors from rubbing against the conduit edge.

When Required by the AHJ (Authority Having Jurisdiction)

Ultimately, the inspector has the final say. If they feel the reaming isn't sufficient or they have a local interpretation of the code that requires bushings in this scenario, you'll need to comply.

Best Practice (Your "Professionalism Standpoint")

Even if technically not required in every case, using a bushing offers an added layer of protection and shows a commitment to quality workmanship. It demonstrates that you've considered the potential for abrasion and taken steps to mitigate it.

In your specific scenario with URD

Given that URD is more susceptible to abrasion than some other types of wire, and that it's often used for higher amperage services that may need larger conductors, it's highly recommended to use bushings, even with properly reamed conduit. The small cost of the bushings is a worthwhile investment to ensure the long-term integrity of the installation.

In Summary: Reaming is a must regardless. Bushings are strongly recommended when using URD wire entering a box from PVC conduit. Always consider the size of the conductors, the bending radius, and the potential for misalignment. Consult with your local AHJ if you have any questions or doubts. Err on the side of caution and use bushings. They're cheap insurance against potential problems down the road. Flag for review