Common issues
- False alarms from dust or oil mist ingress if the detector is used outside its rated environment
- Sensor chamber contamination reducing smoke sensitivity over time
- Loose base connections causing intermittent loop faults
- Loop wiring insulation degradation in high-heat or damp spaces
- Detector head not reseated correctly after cleaning, producing a 'missing device' fault
- Condensation inside the chamber in unheated void spaces triggering nuisance alarms
Inspection checklist
- Visual check for physical damage, discoloration, or paint overspray on the detector head
- Confirm detector address matches the panel database - no orphaned or duplicate addresses
- Functional smoke/aerosol test using a class-approved test method
- Check base terminals for corrosion and secure wiring
- Verify the detector is unobstructed (clearance from beams, ducting, sprinkler heads)
- Cross-check zone/loop response against the panel event log
- Confirm detector location still matches the approved fire control plan
- Check for dust/coating buildup on the sensing chamber louvres
Service intervals
| Functional smoke test, all detectors | annually, per SOLAS II-2 / flag requirements |
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| Panel loop integrity test | annually |
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| Visual inspection of accessible detectors | at each planned maintenance round, typically quarterly |
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| Detector chamber cleaning | as indicated by sensitivity drift, commonly every 3-5 years |
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| Panel battery/backup power test | annually |
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Critical spares
- Replacement detector head - same addressable protocol/family as the loop
- Detector base
- Loop isolator module
- End-of-line resistor/terminator
- Panel test/service tool for the fire alarm system
Safety
- Never isolate or disable a detector without informing the duty officer and logging it
- Re-enable all isolated detectors before hot work is completed or before entering port
- Aerosol test canisters are pressurised - use only in a ventilated space per the approved test method
- The fire control plan must be updated for any detector relocation
Class survey
Falls under the ship's fixed fire detection and alarm system (SOLAS II-2). Surveyors check functional test records, the loop fault log, and that detector positions match the approved fire control plan. This is normally reviewed under the fire detection system survey item, not Continuous Survey Machinery.
Estimated lifetime: Not meaningfully measured in operating hours; addressable smoke detectors are typically given a calendar service life on the order of 10 years by the manufacturer, subject to passing functional tests - confirm against the specific type approval documentation.