30 CFR §18.49
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Connection boxes used to facilitate replacement of cables or machine components shall be explosion-proof. Portable-cable terminals on cable reels need not be in explosion-proof enclosures provided that connections are well made, adequately insulated, protected from damage by location, and securely clamped to prevent mechanical strain on the connections.