In wet locations, field-installed terminals must be composed of which materials?

In wet locations, field-installed terminals must be made from copper. This requirement is primarily due to copper's excellent conductivity and resistance to corrosion, which are critical in situations where moisture is present. Wet locations, such as those found in swimming pools or outdoor environments, expose electrical connections to water, which can lead to oxidation and failure if materials that are less resistant to corrosion are used.

Copper terminals maintain reliability and safety in electrical systems by ensuring a good connection and minimizing the risk of failure due to environmental factors. Other materials like aluminum, steel, or plastic may not provide the same level of conductivity or durability in wet conditions. Aluminum, for instance, can corrode when exposed to moisture and has a higher resistance than copper, making it less suitable for electrical connections in wet environments. Steel can rust when wet, compromising the integrity of connections, and plastic does not conduct electricity, making it unsuitable for terminals designed to facilitate electrical connections.