- Fire detected in corresponding engine nacelle.
- Trigger: 300C fire loop.
- Main entrance door is: open, unsafe, or took longer than 10 seconds to close.
- Trigger: 7 microswitches (one for each draw bolt, one for the door handle).
- One or both inverters have failed. Will also be accompanied by AC ESS or AC MAIN cap to help determine which inverter has failed.
- Trigger: Switching of either the AC Main or AC Ess INV Fail Relay.
- Smoke Detected in the aft cargo compartment.
- Trigger: smoke detector in aft cargo area.
- Oil pressure below 50 PSI. OK during ground ops (40 PSI minimum).
- Trigger: 50 PSI oil pressure switch downstream from oil filter, powered by DC ESS.
- Undervoltage Sensor (UVS) has sensed less than 25V on one of the DC Busses. Usually accompanied by the BUS TIE OPEN cap light.
- Trigger: One of the UVSs sensed less than 25V.
Cabin altitude has exceeded 10,000'.