What type of cable compartment should not include Class 3 circuits?

In this context, the correct response is based on the understanding of the classifications and limitations of electrical circuits. Class 3 circuits are designed to be power-limited, which helps to reduce risks associated with fire hazards and electrical shock. They typically have a maximum power output and voltage which is lower than other classes, making them suitable for communication systems and some types of data transmissions.

Power-limited fire alarm circuits, while essential for safety and building codes, operate under different regulations and classifications. These circuits generally need to meet stringent requirements for reliability and performance in emergency situations. In particular, they must tend to higher power requirements that exceed those permitted for Class 3. This is why fire alarm circuits are not categorized as Class 3; they require their own compartment and considerations due to their critical nature.

Conversely, high-voltage power circuits, as well as low-voltage communication circuits and data transmission cables, may include Class 3 circuits or operate under different classifications that allow for lower voltage and power levels that are safer for general use. This highlights the unique position of power-limited fire alarm circuits in the overall structure of electrical classifications.