Section 118.120 - Equipment installed but not required(a) Fire extinguishing equipment installed on a vessel in excess of the requirements of §§ 118.400 and 118.500 must be designed, constructed, installed, and maintained in a manner acceptable to the Commandant.(b) Use of non-approved fire detection systems may be acceptable as excess equipment provided that: (1) Components are listed and labeled by a nationally recognized testing laboratory (NRTL) as set forth in 29 CFR 1910.7 , and are designed, installed, tested, and maintained in accordance with an appropriate industry standard and the manufacturer's specific guidance;(2) Installation conforms to the requirements of 46 CFR chapter I, subchapter J (Electrical Engineering), especially the hazardous location electrical installation regulations in 46 CFR 111.105 ; and(3) Coast Guard plan review is completed for wiring plans.USCG-2012-0196, 81 FR 48270 , July 22, 2016