Pick the right materials for your distribution box. Choose a. A distribution box, also called a distribution board, DB box, breaker box, consumer unit, load centre, or panelboard depending on region, is the point where electrical power is divided into individual branch circuits. In a typical low-voltage installation, it performs five jobs: Distribution:. Choose the right low voltage distribution box by matching capacity, safety, and environment to your needs for reliable and efficient electrical protection. You can find here a step-by-step guide to help you through the process. Determine the voltage level (e., 230V single-phase or 400V three-phase). But the standard behind the assembly can be very. IEC 61439 is the governing standard for low-voltage switchgear and controlgear assemblies, and it sets verified limits on how a panel can be modified or extended without voiding its compliance basis.