46 CFR § 111.05-31
Grounding conductors for systems
April 15, 2021
(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 (8.4mm2).
(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
Open Table
Size of the largest generator cable or equivalent for parallel generators—AWG-MCM (mm2) | Size of the system grounding conductor—AWG(mm2) | |
---|---|---|
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) |