FSD FSD Troubleshooting & Repair 2 — Questions and Answers
Question 1: What is the recommended corrective procedure when a smoke damper actuator fails?
- Replace the actuator with an identical UL-listed unit and retest operation (Correct answer)
- Bypass the actuator wiring and operate the damper manually
- Install a mechanical fusible link as a temporary substitute
- Reconnect the wiring harness and reset the fire alarm panel
Correct answer: Replace the actuator with an identical UL-listed unit and retest operation
A failed actuator must be replaced with an identical UL-listed replacement unit and the damper fully retested to confirm proper operation before the repair is accepted.
Question 2: How should a technician address light surface corrosion found on fire damper blades that do not affect operation?
- Document the corrosion, clean the affected area, and monitor at next inspection (Correct answer)
- Replace the blades immediately regardless of operational impact
- Apply any available commercial paint to prevent further corrosion
- Leave it undocumented since the damper is still operational
Correct answer: Document the corrosion, clean the affected area, and monitor at next inspection
Light corrosion that does not impair operation should be documented, cleaned, and flagged for monitoring at the next inspection cycle per NFPA 80 maintenance guidance.
Question 3: After replacing a fusible link on a fire damper, what is the correct next step?
- Manually cycle the damper to verify it closes fully and latches correctly (Correct answer)
- Immediately schedule a full building fire alarm test
- Submit the replacement to the AHJ for approval before any testing
- Install a new access door before performing any functional check
Correct answer: Manually cycle the damper to verify it closes fully and latches correctly
After replacing a fusible link, the technician must manually cycle the damper to confirm it closes fully and latches, verifying the repair restored proper function.
Question 4: If a fire damper closes but leaves a visible gap and does not fully seal, which component is most likely defective?
- A worn or missing blade seal or stop (Correct answer)
- The fusible link temperature rating
- The duct collar attachment welds
- The smoke detector wiring
Correct answer: A worn or missing blade seal or stop
A gap when the damper is closed typically indicates worn, damaged, or missing blade seals or blade stops that prevent the blades from forming a tight closure.
Question 5: What is the proper test method to verify a smoke damper is operational after completing a repair?
- Send an activation signal from the control panel and confirm full closure and position feedback (Correct answer)
- Blow air through the duct and observe blade movement
- Manually push blades closed and check for resistance
- Perform a visual inspection only with blades in the open position
Correct answer: Send an activation signal from the control panel and confirm full closure and position feedback
After repair, the smoke damper must be tested by sending an actual activation signal and confirming full closure with correct position feedback to the control system.
Question 6: When troubleshooting an electrically-operated smoke damper that will not respond, what is the first diagnostic step?
- Verify that control voltage is present at the actuator terminals (Correct answer)
- Remove and inspect the fusible link
- Check the ductwork for air leaks around the damper frame
- Test the smoke detector sensitivity level
Correct answer: Verify that control voltage is present at the actuator terminals
Confirming control voltage at the actuator terminals first establishes whether the problem is electrical supply or the actuator itself, directing all further troubleshooting.
FSD FSD Troubleshooting & Repair 2
What is the recommended corrective procedure when a smoke damper actuator fails?