CBCP Building Automation & Control Systems Flashcards
6 cards from real CBCP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CBCP Building Automation & Control Systems flashcards as text
What is the purpose of a 'trend log' in a BAS during commissioning?
Answer: Logging historical data of control variables over time to verify system performance
Trend logs capture time-stamped data for sensors and control outputs, allowing commissioning agents to verify proper system behavior over time.
A VAV (Variable Air Volume) box fails to modulate during FPT. Which BAS component should the commissioning agent check first?
Answer: The DDC controller output signal to the VAV actuator
The DDC controller output signal drives the VAV actuator, so verifying this signal is the logical first diagnostic step.
Which ASHRAE guideline specifically addresses the commissioning process for HVAC&R systems?
Answer: ASHRAE Guideline 0
ASHRAE Guideline 0 defines the commissioning process for new and existing buildings across all systems.
What does the term 'sequence of operations' refer to in a BAS?
Answer: A written description of how control systems respond to various inputs and conditions
The sequence of operations is the narrative description of how the BAS controls equipment under various conditions and modes.
An AHU economizer damper is found fully closed during a 40°F outdoor air temperature condition when free cooling should be available. Which BAS parameter should be reviewed?
Answer: Economizer changeover (enable) setpoint
The economizer changeover setpoint determines the outdoor air temperature or enthalpy threshold at which economizer mode is enabled.
What is the purpose of a 'hardwired interlock' in a BAS control system?
Answer: To provide a software-independent safety shutdown that activates regardless of the BAS program
Hardwired interlocks provide a fail-safe, BAS-independent layer of protection that cannot be overridden by software errors.