CCP CCP Controls & Automation Systems 2 — Questions and Answers
Question 1: What is the purpose of calibrating sensors before functional performance testing of a control system?
- To ensure the BAS graphics display correctly
- To confirm sensors read accurately so control loops respond to true conditions (Correct answer)
- To satisfy the equipment warranty requirements only
- To reduce the number of trend logs needed
Correct answer: To confirm sensors read accurately so control loops respond to true conditions
Sensor calibration ensures that readings sent to the controller reflect actual conditions; uncalibrated sensors cause control loops to respond to false data, producing incorrect system behavior.
Question 2: A commissioning team is verifying an economizer control sequence. At what outside air condition should the economizer be fully open for free cooling?
- When outside air temperature exceeds the high-limit setpoint
- When outside air enthalpy or dry-bulb temperature is below the economizer high-limit setpoint (Correct answer)
- Only during unoccupied hours
- When the chiller is at full capacity
Correct answer: When outside air enthalpy or dry-bulb temperature is below the economizer high-limit setpoint
The economizer opens fully for free cooling when outside air conditions (temperature or enthalpy) are below the high-limit setpoint, allowing outdoor air to cool the space without mechanical refrigeration.
Question 3: During BAS commissioning, what is a 'point-to-point checkout'?
- Verifying network cable connections between BAS controllers
- Confirming that each physical sensor/actuator is correctly wired and mapped to the correct BAS software point (Correct answer)
- Testing communication between two remote buildings
- Reviewing the sequence of operations document for accuracy
Correct answer: Confirming that each physical sensor/actuator is correctly wired and mapped to the correct BAS software point
A point-to-point checkout verifies that each field device is correctly wired, labeled, and mapped to the intended BAS software point before control sequences are tested.
Question 4: What ASHRAE standard provides guidance on the sequence of operations for HVAC control systems in commercial buildings?
- ASHRAE Standard 55
- ASHRAE Guideline 36 (Correct answer)
- ASHRAE Standard 62.1
- ASHRAE Standard 189.1
Correct answer: ASHRAE Guideline 36
ASHRAE Guideline 36 provides high-performance sequences of operation for HVAC systems, giving commissioning agents a benchmark for verifying BAS programming.
Question 5: A Cx agent is testing a chilled water plant control sequence and finds the lead chiller starts before the condenser water pump is proven on. Why is this a problem?
- It wastes energy by running the pump unnecessarily
- The chiller could be damaged due to lack of condenser water flow during start-up (Correct answer)
- The BAS will generate a nuisance alarm only
- This is acceptable per standard commissioning practice
Correct answer: The chiller could be damaged due to lack of condenser water flow during start-up
Chillers require proven condenser water flow before compressor start to prevent high-pressure lockout or refrigerant-side damage; starting without flow confirmation is a serious control sequence deficiency.
Question 6: What is 'hardening' a BAS program, and when does it occur in the commissioning process?
- Encrypting the BAS software against cyber threats, done during design
- Locking control parameters after verification so they cannot be changed without authorization, done near project close-out (Correct answer)
- Installing surge protectors on all BAS panels, done during construction
- Replacing temporary sensors with permanent ones, done during installation
Correct answer: Locking control parameters after verification so they cannot be changed without authorization, done near project close-out
Hardening locks setpoints, schedules, and program parameters after commissioning verification to prevent unauthorized changes that could degrade system performance.
CCP CCP Controls & Automation Systems 2
What is the purpose of calibrating sensors before functional performance testing of a control system?