Elevator machine rooms (hydraulic oil tank, control panels) and hoistway pits (buffer oil, cables) carry fire risk. NFPA 13 sprinkler, NFPA 17A dry chemical and ASME A17.1 are read together. Shunt trip (instant power cut) is critical - elevator must not move during sprinkler discharge.
NFPA 13 Sprinkler Requirement
- Machine room: Ordinary Hazard 1
- Hoistway pit: sprinkler below 610 mm
- Hoistway top: required in hydraulic elevators
- Recessed/quick-response: preferred
- K-factor: K=80 (5.6) sufficient
Shunt Trip Circuit
- Purpose: prevent sprinkler water reaching energized elevator
- Trigger: waterflow or detector
- Heat detector: 57 C (135 F) train setting
- Elevator shutdown: Phase I recall first, then shunt
- Pre-signal: descend to floor before cut
- ASME A17.1 2.27: detailed rule
Phase I and Phase II
- Phase I (Recall): all cars descend to lobby, doors open
- Phase II (Firefighter): key-operated fire control
- Lobby detector: activates recall
- Alternate floor: if lobby has fire
- Smoke detector: in machine-room path
NFPA 17A Dry Chemical
- Application: hydraulic oil tank
- Agent: ABC monoammonium phosphate
- Nozzle: oil-tank overhead aim
- Detection: spot heat 70 C linear
- Alternative: K-class agent for oil fires
Common Issues
- Missing top sprinkler: hydraulic elevator oils
- Shunt-trip untested: annual test mandatory
- Phase I test missing: monthly inspection
- Dirty detectors: machine-room dust
- Water leaks: pit-bottom check
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Sources & Further Reading
NFPA 13, NFPA 17A, ASME A17.1/CSA B44, NFPA 72, EN 81-72. NFPA 13 Sprinkler standard.