(a) A conductor for grounding a direct-current system must be the larger of:
(1) The largest conductor supplying the system; or
(2) No. 8 AWG (8.4mm
2).
(b) A conductor for grounding the neutral of an alternating-current system must meet Table 111.05-31(b).
Table 111.05-31(b)—Neutral Grounding Conductor for Alternating-Current System
| Size of the largest generator cable or equivalent for parallel generators—AWG-MCM (mm
2)
| Size of the system grounding conductor—AWG(mm
2)
|
|---|
| Greater than
| Less than or equal to
|
|---|
| 2 (33.6) | 8 (8.4)
|
| 2 (33.6) | 0 (53.5) | 6 (13.3)
|
| 0 (53.5) | 3/0 (85.0) | 4 (21.2)
|
| 3/0 (85.0) | 350 MCM (177) | 2 (33.6)
|
| 350 MCM (177) | 600 MCM (304) | 0 (53.5)
|
| 600 MCM (304) | 1100 MCM (557) | 2/0 (67.5)
|
| 1100 MCM (557) | | 3/0 (85.0) |
authority: 46 U.S.C. 3306,
3703; DHS Delegation No. 00170.1, Revision No. 01.2. Section 111.05-20 and Subpart 111.106 also issued under sec. 617, Pub. L. 111-281, 124 Stat. 2905
source: CGD 74-125A, 47 FR 15236, Apr. 8, 1982, unless otherwise noted.
cite as: 46 CFR 111.05-31