In small sized constructions, such as small houses or apartments, designers target to develop an economic project. In these buildings, one of the alternatives is to reduce the number of electrical circuits of the electrical installation, only if this reduction does not cause any damage to any functionality of the building.
In this blog post, I will talk about the cases when an electrical circuit can simultaneously supply power outlets and lights, in agreement with the Brazilian standard NBR 5410:2008. This post aims to be informational and the content discussed herein must be understood as information material only. We recommend that a professional engineer be consulted and that the current version of the Brazilian standard NBR 5410 be used during the design and construction of the project.
Generally, NBR 5410 states that power outlets and lights must be supplied by distinct terminal electrical circuits (section 4.2.5.5; terminal electrical circuits are circuits that come from a circuit breaker and go to power outlets and/or lights). However, section 9.5.3.3, which talks about electrical circuits in housing locations (houses and hotel rooms, for example), states exception cases. When the following conditions are met, power outlets and lights can be supplied by the same terminal electrical circuit:
- The designed current of the terminal electrical circuit must be up to 16 A.
- Lights must be divided into two or more terminal electrical circuits.
- Power outlets in the terminal electrical circuit MUST NOT supply kitchen, service areas, or similar locations.
- Power outlets in other locations (that is, power outlets that are not supplying kitchen, service areas, or similar locations) must be divided into two or more terminal electric circuits.
For example, these exceptions allow one to design the same terminal electrical circuit for bedrooms (maybe not including an AC) and hotel rooms, which will reduce the required number of circuit breakers and cables.