The top and bottom wire-bending space for a panelboard enclosure shall be sized in accordance with Table E3907.9.1(1) based on the largest conductor entering or leaving the enclosure. [408.55 (A)]
Exceptions:
- For a panelboard rated at 225 amperes or less and designed to contain not more than 42 overcurrent devices, either the top or bottom wire-bending space shall be permitted to be sized in accordance with Table E3907.9.1(2). For the purposes of this exception, a 2-pole or a 3-pole circuit breaker shall be considered as two or three overcurrent devices, respectively. [408.55(A) Exception No. 1]
- For any panelboard, either the top or bottom wire-bending space shall be permitted to be sized in accordance with Table E3907.9.1(2) where the wire-bending space on at least one side is sized in accordance with Table E3907.9.1(1) based on the largest conductor to be terminated in any side wire-bending space. [408.55(A) Exception No. 2]
- Where the panelboard is designed and constructed for wiring using only a single 90-degree bend for each conductor, including the grounded circuit conductor, and the wiring diagram indicates and specifies the method of wiring that must be used, the top and bottom wire-bending space shall be permitted to be sized in accordance with Table E3907.9.1(2). [408.55(A) Exception No. 3]
- Where there are no conductors terminated in that space, either the top or the bottom wire-bending space, shall be permitted to be sized in accordance with Table E3907.9.1(2). [408.55(A) Exception No. 4]
TABLE E3907.9.1(1) [Table 312.6(B)]
MINIMUM WIRE-BENDING SPACE AT TERMINALS (see note 1)
| WIRE SIZE (AWG or kcmil) | WIRES PER TERMINAL | ||||
| All other conductors | Compact stranded AA-8000 aluminum alloy conductors (see Note 3) | One (see note 2) | Two | ||
| inches | mm | inches | mm | ||
| 14-10 | 12-8 | Not specified | Not specified | — | — |
| 8 | 6 | 11/2 | 38.1 | — | — |
| 6 | 4 | 2 | 50.8 | — | — |
| 4 | 2 | 3 | 76.2 | — | — |
| 3 | 1 | 3 | 76.2 | — | — |
| 2 | 1/0 | 31/2 | 88.9 | — | — |
| 1 | 2/0 | 41/2 | 114 | — | — |
| 1/0 | 3/0 | 51/2 | 140 | 51/2 | 140 |
| 2/0 | 4/0 | 6 | 152 | 6 | 152 |
| 3/0 | 250 | 61/2a | 165a | 61/2a | 165a |
| 4/0 | 300 | 7b | 178b | 71/2c | 190c |
| 250 | 350 | 81/2d | 216d | 81/2d | 229d |
| 300 | 400 | 10c | 254c | 10d | 254d |
| 350 | 500 | 12c | 305c | 12c | 305c |
| 400 | 600 | 13c | 330c | 13c | 330c |
| 500 | 700-750 | 14c | 356c | 14c | 356c |
| 600 | 800-900 | 15c | 381c | 16c | 406c |
| 700 | 1000 | 16c | 406c | 18c | 457c |
- Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector in a direction perpendicular to the enclosure wall.
For removable and lay-in wire terminals intended for only one wire, bending space shall be permitted to be reduced by the following number of millimeters (inches):
- 1/2 inches (12.7 mm)
- 1 inches (25.4 mm)
- 11/2 inches (38.1 mm)
- 2 inches (50.8 mm)
- This column shall be permitted to determine the required wire-bending space for compact stranded aluminum conductors in sizes up to 1000 kcmil and manufactured using AA-8000 series electrical grade aluminum alloy conductor material.
TABLE E3907.9.1(2) [Table 312.6(A)]
MINIMUM WIRE-BENDING SPACE AT TERMINALS AND MINIMUM WIDTH OF WIRING GUTTERS (see note 1)
| WIRE SIZE (AWG or kcmil) | WIRES PER TERMINAL | |||
| One | Two | |||
| inches | mm | inches | mm | |
| 14-10 | Not specified | Not specified | — | — |
| 8-6 | 11/2 | 38.1 | — | — |
| 4-3 | 2 | 50.8 | — | — |
| 2 | 21/2 | 63.5 | — | — |
| 1 | 2 | 76.2 | — | — |
| 1/0-2/0 | 31/2 | 88.9 | 5 | 127 |
| 3/0-4/0 | 4 | 102 | 6 | 152 |
| 250 | 41/2 | 114 | 6 | 152 |
| 300-350 | 5 | 127 | 8 | 203 |
| 400-500 | 6 | 152 | 8 | 203 |
| 600-700 | 8 | 203 | 10 | 254 |
- 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.
Side wire-bending space shall be in accordance with Table E3907.9.1(2) based on the largest conductor to be terminated in that space. [408.55(B)]
The distance between the center of the rear entry and the nearest termination for the entering conductors shall be not less than the distance given in Table E3907.9.1(1). Where a raceway or cable entry is in the wall of the enclosure, opposite a removable cover, the distance from that wall to the cover shall be permitted to comply with the distance required in Table E3907.9.1(2). [408.55 (C)]