What type of fitting may the metal raceway terminate to when installed to reduce electrical noise?

The correct answer is that a metal raceway should terminate to a listed non-metallic fitting in order to reduce electrical noise. Non-metallic fittings have specific properties that help in minimizing electromagnetic interference (EMI) and other forms of electrical noise that can affect the performance of sensitive electronic devices.

Using listed non-metallic fittings can create a barrier that isolates the metal raceway from unwanted electromagnetic fields while maintaining the integrity and performance of the electrical system. These fittings are designed to work effectively with various raceway systems, providing both mechanical support and electrical protection.

In contrast, other fittings such as metal or plastic fittings may not have the same level of isolation and protection against EMI. Metal fittings can potentially conduct noise instead of reducing it, while plastic fittings might not fully meet the necessary requirements for grounding or protection in certain installations. Copper fittings are more specific to grounding applications and would not be appropriate for the goal of reducing electrical noise in this context.