312.6 wire bending space at terminals

[Jpflex]

Looks like i could use some clarification on this again.

According to nec 312.6, table 312.6 B(2) is to be used if a conductor enters or leaves tge enclosure through the wall opposiye its enclosure.

However the 2023 NEC Handbook in exhibit 312.1 shows a 4/0 neutral terminating to a neutral buss that does NOT enter or leave the enclosure through the wall opposite its enclosure.

In contradiction, the handbook does not use the appropriate table 312 6A to determine the proper amount of wire space ( 4 inches)

Instead the NEC handbook uses table 312.6B2 with a result of 7 inches?

 

[Jpflex]

T4 NEUTRAL

 

[Jpflex]

Table 312.6A where conductors do NOT enter or leave wall opposite its terminal

 

[Jpflex]

Table 312 6 B 2 where conductors do enter or leave the wall opposite its terminal

 

[wwhitney]

Agreed that it appears to be in error with respect to the configuration drawn.

But for an enclosed panelboard, compliance with 312.6 is handled by the manufacturer, based on whatever the largest size is that the lug accepts. So in practice the clearance would be at least 7" if 4/0 is the largest conductor that bar accepts, to allow you to install a 4/0 conductor that does exit out the bottom.

Cheers, Wayne

 

[Jpflex]

Agreed that it appears to be in error with respect to the configuration drawn.

But for an enclosed panelboard, compliance with 312.6 is handled by the manufacturer, based on whatever the largest size is that the lug accepts. So in practice the clearance would be at least 7" if 4/0 is the largest conductor that bar accepts, to allow you to install a 4/0 conductor that does exit out the bottom.

Cheers, Wayne

I would not think electricians would be measuring these gutter and wire bending spaces for every single wire installed for everyday projects.

However, for testing purposes I must know the code. When the code book gets it wrong, it makes me wrong during testing.

I Guess you are saying that if a manufacture box allows a specific maximum size wire to be terminated within, the manufacture would provide adequate gutter space

The other confusing code is the cross sectional conductor area fill limit per splice or without splice in a box

 

[don_resqcapt19]

I Guess you are saying that if a manufacture box allows a specific maximum size wire to be terminated within, the manufacture would provide adequate gutter space

The wire bending space requirements in UL 67 for panels, disconnects, and meter enclosures are identical to those found in Article 312.

 

[jim dungar]

I Guess you are saying that if a manufacture box allows a specific maximum size wire to be terminated within, the manufacture would provide adequate gutter space

Yes.

The manufacturer probides spacing for a specific wire range whivh msy br less than what the lug can actually hold.