Which of the following is NOT included in the required system drawings?

The correct answer is that power supply connections are not included in the required system drawings for dry chemical extinguishing systems as specified by NFPA 17. The primary purpose of system drawings is to provide a clear visual representation of the system's components and layout, focusing on elements that are critical for the proper design, installation, and operation of the dry chemical extinguishing system.

System drawings typically include details about components that directly relate to the extinguishing mechanism and the specific engineering aspects of the installation, such as fuel shutoff devices, appliances that will be protected, and nozzles through which the extinguishing agent is discharged. These elements are vital for understanding how the system interacts with potential fire hazards and ensures effective suppression.

Power supply connections, while essential for the operation of the system, are considered part of the electrical design and are typically detailed in separate electrical drawings rather than in the specific system drawings for the extinguishing system. This distinction allows the focus of the system drawings to remain on the fire protection features and their functional layout without the additional complexity of electrical schematics.