46 CFR 132.340: Equipment installed although not required.

(a) A vessel may install fire extinguishing equipment beyond that required by this subchapter, unless the excess equipment in any way endangers the vessel or the persons aboard. This equipment must be listed and labeled by an independent, nationally recognized testing laboratory (NRTL) as that term is defined in 46 CFR 161.002-2, and must be designed, installed, tested, and maintained in accordance with an appropriate industry standard and the manufacturer's specific guidance.

(b) Use of non-approved fire detection systems may be acceptable as excess equipment, provided that:

(1) Components are listed and labeled by an NRTL as that term is defined in 46 CFR 161.002-2, 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.