What should be done to raceways that are exposed to widely different temperatures?

In situations where raceways are exposed to widely different temperatures, sealing them is essential to maintain the integrity and performance of the electrical system. Sealing helps prevent moisture ingress, dust, and contaminants that can affect the electrical conductors or equipment inside the raceway. When temperatures fluctuate significantly, condensation can occur, which may lead to corrosion or short circuits if water enters the raceway. Therefore, sealing creates a barrier that protects against such environmental impacts while also aiding in maintaining a consistent operating temperature for the contents within the raceway.

Insulation could be useful in some scenarios but isn't specifically required for raceways in the context of large temperature differentials. Grounding is primarily for safety and fault protection, not temperature-related issues. Coating can offer some protection but won't address the issues that come from temperature fluctuations as effectively as sealing would. Thus, sealing is the best practice in these instances to ensure functionality and safety.