IEC 61439-3 (DBO) compliance requirements, testing procedures, and design considerations for Lighting Distribution Board assemblies. Design requirements for low voltage distribution boxes cover NEC, IEC, and safety standards to ensure reliable, compliant electrical installations. When you put things the right way, you can keep systems safe in homes, businesses, and factories. The IEC (International Electrotechnical Commission) and BS 7671 (British Standard for Electrical Installations) both provide essential requirements for electrical installations, including those for fuse boards like garage unit, consumer unit and distribution board. Electrical switches and other. A full Lighting Library™ subscription includes access to all lighting standards in one place and access to illuminance recommendations from IES in our Illuminance Selector.