The requirement to ground equipment fastened in place exempts which of the following?

Double-insulated equipment is designed with an additional layer of insulation that provides protection from electrical shock without the need for a grounding connection. This type of equipment typically uses two layers of insulation or a reinforced insulation system, making it safe to use without being grounded. Since these devices are engineered to prevent electrical shock risk through double insulation, they are exempt from the grounding requirement applicable to equipment that is fastened in place.

On the other hand, fire pumps and portable electrical appliances typically do require grounding for safety, especially since they may present a higher risk of electric shock if a fault occurs. Grounding serves as a safety measure, directing stray currents safely away from users. Thus, the exemption for double-insulated equipment highlights the unique safety features of such devices, allowing them to operate safely without grounding while still adhering to electrical safety standards.