NYC Health Hospitals Control Systems
Technician Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1. A newly installed Building Automation System (BAS) controlling
multiple air handling units in a hospital begins showing unstable
temperature control in several patient care areas. The discharge air
temperature oscillates above and below the setpoint even though the
heating and cooling coils, sensors, and actuators have all passed
individual component tests. As the Control Systems Technician, which
control system issue should be investigated first because it is the most
likely cause of the continuous oscillation?
A. Insufficient chilled water pressure to the cooling coil
,B. A proportional band that is too wide
C. Improper PID tuning, particularly excessive proportional gain or
inadequate integral settings
D. Dirty air filters creating excessive static pressure
Rationale: Temperature oscillation in a properly functioning control loop is
most commonly caused by improper PID tuning. Excessive proportional
gain or poorly adjusted integral action causes the controller to overcorrect
continuously, resulting in hunting around the setpoint. Mechanical
problems generally produce slow response rather than repeated
oscillation.
2. During preventive maintenance on a differential pressure transmitter
used to monitor hospital operating room pressurization, the technician
notices that the transmitter consistently reads 0.12 inches water
column higher than a recently calibrated reference manometer. Which
action should be performed before replacing the transmitter?
A. Increase the BAS alarm limits
B. Replace the pneumatic tubing
C. Perform a zero and span calibration according to manufacturer
specifications
D. Install a larger pressure transmitter
,Rationale: When a transmitter consistently reads high but otherwise
responds normally, calibration should be performed before considering
replacement. Zero and span adjustments frequently restore measurement
accuracy, minimizing unnecessary equipment replacement and maintaining
reliable control performance.
3. A VAV terminal unit serving several examination rooms fails to
maintain airflow despite receiving the correct airflow setpoint from
the Building Automation System. Which diagnostic step should be
performed first to isolate whether the problem is in the controller or
the field device?
A. Replace the VAV controller immediately
B. Increase supply fan speed
C. Command the actuator manually from the BAS and observe damper
movement
D. Replace the airflow sensor
Rationale: Manually commanding the actuator verifies communication,
controller output, actuator operation, and mechanical linkage
simultaneously. If the damper responds correctly, the problem likely
involves sensor input or programming rather than actuator failure.
4. A hospital chiller plant uses BACnet communication between
controllers, supervisory workstations, and field devices. Several
, controllers suddenly become unavailable while the remainder of the
network continues operating normally. Which condition is the most
likely cause?
A. Excessive chilled water flow
B. Defective compressor contactor
C. A communication failure affecting one BACnet network segment or
controller
D. Low condenser water temperature
Rationale: BACnet networks are segmented. If only several controllers lose
communication while others remain operational, the most probable cause
is a network wiring issue, failed router, terminated segment, or controller
communication failure affecting only that portion of the network.
5. A technician measures the output of a temperature transmitter
specified as 4–20 mA. The sensor indicates exactly half of its calibrated
temperature range. What output current should be expected?
A. 4 mA
B. 8 mA
C. 12 mA
D. 20 mA
Technician Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A newly installed Building Automation System (BAS) controlling
multiple air handling units in a hospital begins showing unstable
temperature control in several patient care areas. The discharge air
temperature oscillates above and below the setpoint even though the
heating and cooling coils, sensors, and actuators have all passed
individual component tests. As the Control Systems Technician, which
control system issue should be investigated first because it is the most
likely cause of the continuous oscillation?
A. Insufficient chilled water pressure to the cooling coil
,B. A proportional band that is too wide
C. Improper PID tuning, particularly excessive proportional gain or
inadequate integral settings
D. Dirty air filters creating excessive static pressure
Rationale: Temperature oscillation in a properly functioning control loop is
most commonly caused by improper PID tuning. Excessive proportional
gain or poorly adjusted integral action causes the controller to overcorrect
continuously, resulting in hunting around the setpoint. Mechanical
problems generally produce slow response rather than repeated
oscillation.
2. During preventive maintenance on a differential pressure transmitter
used to monitor hospital operating room pressurization, the technician
notices that the transmitter consistently reads 0.12 inches water
column higher than a recently calibrated reference manometer. Which
action should be performed before replacing the transmitter?
A. Increase the BAS alarm limits
B. Replace the pneumatic tubing
C. Perform a zero and span calibration according to manufacturer
specifications
D. Install a larger pressure transmitter
,Rationale: When a transmitter consistently reads high but otherwise
responds normally, calibration should be performed before considering
replacement. Zero and span adjustments frequently restore measurement
accuracy, minimizing unnecessary equipment replacement and maintaining
reliable control performance.
3. A VAV terminal unit serving several examination rooms fails to
maintain airflow despite receiving the correct airflow setpoint from
the Building Automation System. Which diagnostic step should be
performed first to isolate whether the problem is in the controller or
the field device?
A. Replace the VAV controller immediately
B. Increase supply fan speed
C. Command the actuator manually from the BAS and observe damper
movement
D. Replace the airflow sensor
Rationale: Manually commanding the actuator verifies communication,
controller output, actuator operation, and mechanical linkage
simultaneously. If the damper responds correctly, the problem likely
involves sensor input or programming rather than actuator failure.
4. A hospital chiller plant uses BACnet communication between
controllers, supervisory workstations, and field devices. Several
, controllers suddenly become unavailable while the remainder of the
network continues operating normally. Which condition is the most
likely cause?
A. Excessive chilled water flow
B. Defective compressor contactor
C. A communication failure affecting one BACnet network segment or
controller
D. Low condenser water temperature
Rationale: BACnet networks are segmented. If only several controllers lose
communication while others remain operational, the most probable cause
is a network wiring issue, failed router, terminated segment, or controller
communication failure affecting only that portion of the network.
5. A technician measures the output of a temperature transmitter
specified as 4–20 mA. The sensor indicates exactly half of its calibrated
temperature range. What output current should be expected?
A. 4 mA
B. 8 mA
C. 12 mA
D. 20 mA
