No self-contained unit either for air-conditioning or for refrigerated spaces for ship's stores need comply with Sec. 58.20-5, 58.20-10, 58.20-15, 58.20-20(a), or 58.20-20(b) of this chapter if--
(a) The unit uses a fluorocarbon refrigerant allowed by part 147 of this chapter;
(b) The manufacturer certifies that the unit is suitable for its intended purpose; and
(c) Electrical wiring meets the applicable requirements in subchapter J of this chapter.