What does NEC 2023 300.14 say about junctions with a dimension > 8"?

Question

NEC 2023 300.14 states:

300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points. At least 150 mm (6 in.) of free conductor, measured from the point in the box where it emerges from its raceway or cable sheath, shall be left at each outlet, junction, and switch point for splices or the connection of luminaires or devices. The 150 mm (6 in.) free conductor shall be permitted to be spliced or unspliced. Where the opening to an outlet, junction, or switch point is less than 200 mm (8 in.) in any dimension, each conductor shall be long enough to extend at least 75 mm (3 in.) outside the opening.

I do a fair bit of computer programming, and I'm reading this as a conditional missing an "else":

wireLength = 6" // measured from cable sheath/entrance to box
if (maxJunctionDimension < 8") {
    wireLengthFromFront = 3"
} else {
    wireLengthFromFront = ???"
}

My best interpretation is "you don't need to worry about extending 3 inches outside the box if the box has a dimension > 8 inches" but I can't fathom why that would be the case.

Can anybody clarify what's going on here?

Answer 1

Because you can put your hands into an 8" opening to work and make connections.

3" out of the box is so that you can make connections that will be stuffed back into small boxes you cannot reach into and make connections.

Mind you, an 8x8 or larger box other than a breaker panel is unusual in residential anyway.

Incorrect conditionals & variable in your pseudocode. Corrected below:

wireLength ≥ 6" // measured from cable sheath/entrance to box
if (minJunctionDimension < 8") { 
    wireLengthFromFront ≥ 3"
} else {
    wireLengthFromFront ≥ 0"
}

The language is quite specific that if the opening is less than 8" in any dimension you need (at least) 3" out the front, so a long gang box still needs 3" out the front. A box with a 7.95" x 24" opening would need 3" out the front. It does not say "if any dimension is greater than..."

A practical consideration rather than "code minimum" for a long gang box as you mention in comments is that apart from (at least) 6 inches and (at least) 3 inches out the front, you need enough wire length to make the required connections to devices, so if a wire is able to come out the front 3.5" and is 7" long but needs to go to the other end of the box to hit the switch or receptacle it connects to, then...it needs to be longer. If it's more than 11.99" you'll need to count it as two wires for box fill. However, you can pigtail for free, box-fill-count-wise; and the code minimum makes sure you can, in fact, make a pigtail connection.