The Fifth Edition of the Standard for Power Converter/Inverter Systems for Land Vehicles and Marine Crafts, UL 458 has been issued to reflect the latest ANSI approval date and to incorporate the proposals dated August 12, 2005, December 9, 2005, and March 17, 2006. The proposals included the following:

• The addition of the definition for "unit" and replacement of the terms converter, inverter, converter system, or inverter system as appropriate throughout the Standard.
• The deletion of paragraph 1.9 which addresses issues specific to the certification of a product.
• The revision of requirements to require a distribution panelboard when two to five circuits are provided.
• The clarification of the reference to the ASTM A653 standard for the Corrosion Test.
• The revision to update the table and standard reference in paragraph 37.1.9 for thermocouple requirements.

These requirements cover fixed and stationary power converters, power-converter systems, and accessories having a rated nominal input of 120, 120/240, or 240 V, alternating current and a nominal output of 24 V or less, direct current. These converters are intended for use within land vehicles where not directly exposed to outdoor conditions, and are intended to be employed in accordance with the National Electrical Code, NFPA 70.