Vent
But under the bert is considered vented as per the USCG REG. Here is the REG. B. 6. Enclosure Definition. The term "enclosure," as used in electrical system regulations, has two different meanings: a. In Paragraph 183.410(b)(2)(ii), "enclosure" is used as a general term to describe engine boxes, engine compartment hatch covers, and other similar engine compartment boundaries. These "enclosures" do not have to meet any measures of "tightness and physical size limitations." Generally, the space between these "enclosures" and electrical components in question is open to the atmosphere because of the design configurations of the type of boats where the isolation criteria of 183.410(b)(2)(ii) would apply. Such an enclosure is not installed inside an engine room in order to subdivide the engine room into areas where an ignition source is permitted. b. The second use of "enclosure" in Section 183.450 is meant to include items such as panel boxes, electrical component housings, and potted electrical components with external pigtails or terminals. Again, there is no degree of tightness or size. This section allows exceptions to terminations that are "enclosures" because the terminations are not physically exposed to possible damage and they are generally restrained by other means in addition to the termination itself. 7. Ventilation of Batteries. a. The regulation requires a means of venting hydrogen gas discharged by a battery. In order to meet the requirements of 183.420(a) (securing of batteries) and 183.420(b) (protection of the ungrounded terminal), it is common practice to install battery boxes. The only regulation presently in effect concerning ventilation does not address battery compartments or boxes. b. The venting of hydrogen gas does not require a ventilation system per se (ducts, blowers, etc.). As long as the gas can escape the compartment, the installation meets the intent of 183.420(e). Engine compartments are generally considered open enough so as to prevent the collection of hydrogen gas. Required ventilation systems on boats with engine compartments, engine air intakes, normal holes, gaps, and loose fitting hatch covers create sufficient air flow and escape ports for hydrogen gas to dissipate adequately. Similarly, holes located in the top of a battery box would prevent hydrogen gas from accumulating in the box. B.7. c. The use of sealed, maintenance-free batteries is an acceptable alternative to installation of the battery in a well-ventilated area; however, all maintenance-free batteries are not totally sealed. Some have a small hole for hydrogen to escape. The builder must use caution. In addition, if a builder does not ventilate the battery area, the company should label that area "FOR USE ONLY WITH FULLY SEALED MAINTENANCE-FREE BATTERIES" so that a boat owner who changes batteries is sure to use a correct type. As can be seen a cover over tne battery is more important than venting. Vinny
And have they started requiring vents on diesel boats?