HVAC Building Automation Systems 2

Question 1

Which communication protocol is most commonly used for BAS integration with lighting control systems?

Accepted Answer

BACnet

Answer

BACnet is the dominant open protocol for BAS integration across HVAC, lighting, and other building systems.

Question 2

In a BAS, what does a PID controller stand for?

Accepted Answer

Proportional-Integral-Derivative

Answer

PID stands for Proportional-Integral-Derivative, a feedback control algorithm that minimizes error between setpoint and measured value.

Question 3

What is the primary function of a supervisory controller in a BAS hierarchy?

Accepted Answer

Coordinate multiple field controllers and enforce global strategies

Answer

Supervisory controllers coordinate field-level DDC controllers and implement global optimization strategies like demand limiting.

Question 4

An HVAC technician notices a BAS trend log shows supply air temperature oscillating rapidly around setpoint. What is the most likely cause?

Accepted Answer

PID loop with too-high proportional gain

Answer

Excessive proportional gain causes hunting or oscillation around setpoint in a PID control loop.

Question 5

What BACnet object type is used to represent a physical analog input such as a temperature sensor?

Accepted Answer

Analog Input

Answer

The BACnet Analog Input object type represents a physical analog measurement such as temperature or pressure.

HVAC - Heating, Ventilation, and Air Conditioning Practice Test