In what type of construction or facility should the branch circuits supplying devices always be protected?

The correct answer revolves around the specific requirements for guest room applications, especially in the context of electrical safety and usage. Guest rooms in hotels and similar facilities often have unique electrical needs since they provide accommodations for the public. This leads to certain safety regulations and standards that must be adhered to for the protection of both guests and the property.

In guest rooms, branch circuits supplying devices such as lighting, outlets, and appliances need to be safeguarded to prevent electrical hazards. This includes the need for ground fault circuit interrupters (GFCIs) in areas where moisture is present, like bathrooms or near sinks. Additionally, proper circuit protection helps to avoid overloads and short circuits, ensuring guest safety and comfort during their stay.

Other types of construction or facilities, while they also require circuit protection, do not have the same level of public interaction and thus might not face the same regulations concerning branch circuits. Offices, industrial settings, and service areas have different electrical layouts and demands, focusing more on operational efficiency or specific equipment needs rather than the safety protocols necessary in a guest room environment. This distinction highlights the necessity of protecting branch circuits specifically in the context of guest accommodations.