What kind of installations require that the weights of fixtures be marked on outlets?

The requirement to mark the weights of fixtures on outlets generally applies to any lighting fixture. This practice is crucial for ensuring the safety and stability of the installation, as it helps electricians and other installers understand the load that the outlet can support. When the weight of the fixture is marked, it provides clear information to anyone involved in the installation or maintenance process, allowing them to make informed decisions about hardware, supports, and installation methods.

It's important for all lighting fixtures to have this information available because certain fixtures, depending on their weight and design, may necessitate specific mounting techniques or equipment to prevent accidents or failures. By marking the weight on outlets, it enhances safety standards and helps to facilitate proper installation practices across various types of lighting installations. This is not restricted to a minimum weight threshold or only specific types of fixtures; hence, the answer encompasses all lighting fixtures.