NASA-LLIS-0041
Lessons Learned - Emergency Power-Down Procedures for Multiple Fuel Cells; Fuel Cell Helium Ingestion; Crew Module Fire Alarm and/or Electrical Component Activations; Vehicle Data Down Link
active, Most Current
| Organization: | NASA |
| Publication Date: | 25 November 1991 |
| Status: | active |
| Page Count: | 3 |
scope:
Description of Driving Event:
Fuel cells are connected to the orbiter power busses via a motorized switch. OMI emergency procedures for powering down fuel cells assume redundant ground power is connected to the orbiter and calls for only one disconnect sequence fuel cell 1, 2, then 3. The power to disconnect the FC is delivered through the same busses they are being disconnected from. During a multiple fc failure (i.e. FC 2 & 3) with no ground power connected, the OMI requires FC 1 to be disconnected first. Since FC 1 was the only one operating correctly and suppling the busses with power, switching it off first removed the power needed to disconnect the rest.
Document History
NASA-LLIS-0041
November 25, 1991
Lessons Learned - Emergency Power-Down Procedures for Multiple Fuel Cells; Fuel Cell Helium Ingestion; Crew Module Fire Alarm and/or Electrical Component Activations; Vehicle Data Down Link
Description of Driving Event:
Fuel cells are connected to the orbiter power busses via a motorized switch. OMI emergency procedures for powering down fuel cells assume redundant ground power is...
References
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