You've hit on a point of confusion that many people encounter with NEC 312.6 and the handbook examples. Let's break down why the handbook is seemingly contradicting itself and clarify how to apply the code correctly.

The Issue: When to Use 312.6(B)(2)

The key to understanding this lies in the entire path of the conductor within the enclosure. It's not just about where it terminates but how it's routed.NEC 312.6(B)(2) and Table 312.6(B)(2) are used when a conductor enters and leaves the enclosure through the wall opposite its termination point. The handbook example is depicting the wire being pulled straight across the panel and terminating at the neutral bus. This path requires the wire to enter and leave on opposite walls.

Why the Handbook Uses Table 312.6(B)(2) in the Example

Here's why the handbook uses Table 312.6(B)(2) even though the conductor is terminating on the neutral bus inside the enclosure: Conductor Routing

If the conductor enters the enclosure on one side, travels across the entire width of the enclosure, and then terminates on the neutral bus that's effectively on the opposite side (even if technically slightly inward), then it's treated as entering and leaving the enclosure on opposite walls. The routing mimics the situation the code intends 312.6(B)(2) to address.

Increased Bending Space

This is because the wire is entering, bending, and going across the entire enclosure.

Why Not Use Table 312.6(A)?

Table 312.6(A) is for situations where the conductor enters and terminates on the same wall or adjacent wall, without needing to be routed across the entire enclosure to reach the termination point. The example in the handbook is NOT that.

In Summary

The handbook example is designed to illustrate a specific scenario where, due to the routing of the conductor, the larger bending space requirement of Table 312.6(B)(2) applies. It's not necessarily a contradiction, but a more specific application of the rule.

How to Decide Which Table to Use1. Trace the Conductor Path

Most importantly, consider the entire path of the conductor inside the enclosure. Does it have to bend sharply and traverse the entire enclosure to reach its termination point? If so, 312.6(B)(2) likely applies.
2.

Assess the Termination Point

Where is the conductor terminating in relation to its entry point? Is it directly in front of or next to where it enters, or does it have to cross the entire enclosure?3.

Consider Physical Constraints

Even if a conductor could technically terminate directly next to its entry point, sometimes physical limitations (like the placement of a large bus bar or other equipment) force it to cross the enclosure. This may necessitate using Table 312.6(B)(2).

Important Considerations Handbook as Guidance

Remember, the handbook is interpretive, not code. It helps clarify the code, but the actual NEC wording is what governs.

Local Inspector

When in doubt, consult with your local electrical inspector. They have the final say in how the code is applied in your jurisdiction.

Manufacturer's Instructions: Always follow the manufacturer's instructions for wire bending space within their enclosures, as these can sometimes be more restrictive than the NEC.In conclusion, the handbook example appears contradictory at first glance but is actually applying 312.6(B)(2) because of the required routing of the conductor inside the enclosure. Understanding the reason* behind the different tables (adequate bending space for the specific wiring configuration) is key to applying them correctly. Flag for review