If you do NOT see a FIRE DETECT CAS message during the fire test, what does this imply?

• A. The fire detect loop has possibly sprung a leak releasing the hydrogen gas, opening the switch at the end of the loop triggering the FIRE DETECT CAS message.
• B. The fire detect test is functioning normally.
• C. The system requires immediate maintenance.
• D. The Fire Detect CAS message is not relevant.

Answer: (A)

In a fire-detection test, the loop is filled with a test agent (hydrogen gas) to trigger the detector and produce the FIRE DET CAS alert. If you do not see that alert during the test, the most plausible fault is a leak in the fire-detect loop. A leak would allow the test gas to escape or not reach the sensing element properly, preventing the end-of-loop switch from registering the fire condition as intended and thus the CAS message may not display. This indicates the system isn’t responding as it should, and maintenance should be performed to locate and repair the leak or other loop integrity issues.