312.6a clarification

[mark32]

Just to be sure, in the following thread

http://forums.mikeholt.com/showthread.php?t=98592&highlight=312.6

Pierre posted a few great pics in post #7, in the first pic you'll see the feeder coming in from the right side of the panel and then terminates into the main. Now, when taking the measurement to comply with 312.6a, one would measure from the lug, in this case, to the wall in which the feeder enters. Is that correct? What about the second pic, would you measure from the breaker down to the bottom of the panel? And in the fourth pic, you would measure from the load terminals to the top of the panel?

 

[mark32]

Here are the pics, the order has been reversed. The last pic I referred to in the first post is the middle photo and the second I mentioned is the last one.

 

[Pierre C Belarge]

Hello Mark
If you are referencing this photo:

Then I would not see an issue, as the reference in 312.6(A) is not applicable, as the wording does not apply to this portion of the installation. My commment is based on how far, and from where they enter/leave the enclosure to where they are terminated.

I believe the bending radius of the conductor itself (bent in a U shape) would be of concern if bent too tightly.

 

[mark32]

Thank you Pierre for the reply. Okay, forget that last pic, in the first pic how would you take the measurement that ensures you would be in compliance with 312.6a? It's how the measurement is made that I'd like to know.

 

[mark32]

Again, referring to the first pic, going by this statement "Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector (In the direction that the wire LEAVES the terminal) to the wall, barrier, or obstruction". So, does one measure from the lug straight up to the top of the panel to get the measurement or from the lug to the right side of the panel in which the conductors enter the panel?

 

[Dennis Alwon]

Again, referring to the first pic, going by this statement "Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector (In the direction that the wire LEAVES the terminal) to the wall, barrier, or obstruction". So, does one measure from the lug straight up to the top of the panel to get the measurement or from the lug to the right side of the panel in which the conductors enter the panel?

You measure from the lug straight up not to the side the wires enter. Look at 312.6(A) note at the bottom of the table

Note: Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector (in the direction that the wire leaves the terminal) to the wall, barrier, or obstruction.

 

[Pierre C Belarge]

Typically, the type of measurement you are describing is more for the manufacturers to be able to properly design the size of the enclosure.

 

[mark32]

Thank you Dennis for clearing that up. I wonder if that was a dumb question as I've read almost all the threads on this topic here and no one seemed to asked how the measurement was taken. I can't find the link at this moment, but I saw a graphic this morning in which the author (Of the electrical book) showed the measurement to be taken, in this example, from the lug to the wall in which the conductors enter.

 

[Dennis Alwon]

Not a dumb question at all, in fact someone either here or at ET forum said his inspector interpreted it the other way. So it is confusing if you miss the note. The note is pretty clear.