CFR › Title 46 › Part 129 › §129.32646 CFR §129.326Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkIf a dual-voltage generator is installed on an OSV—(a)The neutral of the dual-voltage system must be solidly grounded at the switchboard's neutral bus and be accessible for checking the insulation resistance of the generator; and(b)Ground detection must be provided that—(1)For an alternating-current system, complies with § 111.05-27 of this chapter; and(2)For a direct-current system, complies with § 111.05-29 of this chapter.