CBCP Building Automation & Control Systems Flashcards

What is the primary function of a Building Automation System (BAS) in a commissioned facility?

Answer: Centralized monitoring and control of HVAC, lighting, and other building systems

A BAS integrates and automates control of HVAC, lighting, and other building systems to optimize performance and energy use.

Which communication protocol is most widely used in modern BAS for interoperability between devices from different manufacturers?

Answer: BACnet

BACnet (Building Automation and Control Networks) is the ASHRAE/ANSI standard protocol enabling interoperability across different BAS vendors.

During commissioning, what is a 'setpoint' in a BAS context?

Answer: The target value a control system attempts to maintain, such as 72°F room temperature

A setpoint is the desired target value that the control loop continuously works to achieve and maintain.

What type of control loop continuously compares measured output to the setpoint and adjusts the control signal accordingly?

Answer: Closed-loop (feedback) control

Closed-loop feedback control uses the measured output to continuously correct deviations from the setpoint.

A DDC (Direct Digital Control) controller receives a 4–20 mA signal from a duct static pressure sensor. What does the 4 mA signal represent?

Answer: The minimum (zero) value of the measured range

In a 4–20 mA loop, 4 mA corresponds to the minimum (0%) of the measurement range, and 20 mA corresponds to the maximum (100%).

During functional performance testing (FPT) of a BAS, a commissioning agent triggers an occupied mode override. What is the primary purpose of this test?

Answer: To verify the BAS correctly transitions systems to occupied setpoints and schedules

The occupied override test confirms the BAS correctly activates HVAC and lighting to occupied-mode setpoints as programmed.