§ 23.9 Special requirements for complete devices.
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
Telephones and signaling devices will be considered nonpermissible if used under any of the followings conditions:
(a) Without the approval plate, mentioned hereafter.
(b) With unprotected openings in any of the explosion-proof compartments. This condition refers to any openings in these compartments, but especially to those equipped with removable covers.
(c) If not complete with all of the parts considered in the approval.
(d) If installed or connected otherwise than in accordance with the instructions furnished by the manufacturer.
(e) If modified in any manner not authorized by MSHA.
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