Which of the following is typically verified by a functional performance test?

• A. Verification of sensor wiring integrity only
• B. Verification of power supply capacity
• C. Checks of branding compatibility of controllers
• D. Setpoints, interlocks, sequencing, energy targets, and alarm behavior

Answer: (D)

Functional performance testing focuses on how the control system behaves when it operates as designed, not just on individual hardware elements. It checks that the system actually accomplishes its intended functions in real conditions. This means verifying that setpoints are reached and maintained, the correct sequencing of operations occurs (the order and timing of actions like startup, cooling, heating, and ventilation), interlocks prevent unsafe or undesired actions, energy targets are met or tracked as planned, and alarms trigger and respond correctly when conditions warrant them. It tests the integrated behavior of controllers, sensors, actuators, and the human–machine interface to ensure the entire control strategy works as intended.

Other options focus on aspects outside dynamic operation: wiring integrity checks examine electrical connections rather than how the system behaves; power supply capacity tests assess electrical supply adequacy, not control logic; branding compatibility relates to procurement or interoperability, not system functionality. So the option detailing setpoints, interlocks, sequencing, energy targets, and alarm behavior best captures what a functional performance test verifies.