When is it acceptable for items like blowers and fans to be unprotected?

Items like blowers and fans can be considered unprotected when they are intended to be installed inside ducts or cabinets that provide protection, or when they are engine driven and comply with specific standards such as ABYC P-4 regarding Marine Inboard Engines.

When blowers and fans are housed within ducts or cabinets, they are safeguarded from potential physical damage, exposure to water, and dirt, which justifies their unprotected status in those contexts. This design consideration ensures that the equipment operates efficiently and safely.

Additionally, if these components are engine-driven and meet the stringent requirements set forth in the ABYC standards, they are deemed acceptable for unprotected use because they are designed to operate in the specific conditions associated with marine inboard engines. This ensures that not only are the components capable of withstanding the rigors of their environment, but they also are aligned with accepted safety practices within the marine industry.

Therefore, both contexts reflect conditions under which it is permissible for blowers and fans to be unprotected, making the combined understanding of these two scenarios the basis for the correct answer.