The tables below are being developed to determine failure modes of the equipment, and actions required. (Credit for this goes to Rachel Cunningham)

FC-17 liquid cooling system
System failure mode	What the system sees	Automatic system response
Leak in tubing to the outside world (impossible for leak to be inside MVD)	Drop in fluid pressure (timing depends on location of sensor)	Shutdown of fluid cooling system Shutdown of all electronics Air cooling system remains on
Pump failure or change in power level	Flowmeter shows change in flow	Immediate shutdown of cooling system and electronics If change is gradual, temperature sensors will sense trouble and issue a warning/shutdown
Chiller failure or change in power level	Rise in temperature of LDOs and in flow loop	Warning when temperature spec is exceeded Shutdown when highest possible operating temperature is reached
Failure of "dirty" power supply	Cooling system goes down: Flowmeter shows loss of flow as it turns off Temperature of LDOs begins to rise	Turn off all electronics Air cooling system is off already
Loss of "clean" power supply	Electronics are down, but F, T sensors are up	Leave cooling system running uncontrolled (it can turn itself off if limits are exceeded)

Unified Air Cooling System
System failure mode	What the system sees	Automatic system response
Fan failure or change in power level	Sudden drop in air flow Slow rise in temperature of MCMs	Immediate shutdown if air flow drops too much If change is gradual, temperature sensors will sense trouble and issue a warning/shutdown
Chiller failure or change in power level	Rise in temperature of MCMs	Warning when temperature spec is exceeded Shutdown when highest possible operating temperature is reached
Loss of efficiency in heat exchanger	Very gradual rise in temperature of MCMs and flow loop	Not applicable to ancillary controls; should be dealt with by making sure air is very clean in the first place, filters, or regular maintenance
Leak to the outside world	Rise in temperature of main enclosure of MVD Eventual rise in temperature of MCMs Rise in humidity	Warning when temperature inside enclosure rises above spec Warning if MCM temperature rises above spec Highly unlikely that this would bring about shutdown conditions
Failure of humidity control system	Rise in humidity in flow loop	Warning when humidity spec is exceeded in either direction This should never cause shutdown, since we can recover good data if we know how much the Rohacell is changing? Note: we're not monitoring this system very closely. If it fails, we won't know why.
Failure of "dirty" power supply	Air cooling system goes down: Flowmeter shows loss of airflow Temperature of MCMs begins to rise	Turn off all electronics
Loss of "clean" power supply	Electronics are down along with detailed sensors, but F, T, H sensors are up	Leave system running uncontrolled (it can turn itself off if limits are exceeded

A System's-Eye View of Life
Occurrence	Automatic system response
Any LDO temperature rises above X	Warn user of occurrence
Any LDO temperature rises above Y	Shut down electronics, cooling system can remain on Inform user of shutdown and where trouble was
Any MCM temperature rises above X	Warn user of occurrence
Any MCM temperature rises above Y	Shut down electronics, cooling system can remain on Inform user of shutdown and where trouble was
Air flow rises above (spec) or falls below (spec)	Warn user of occurrence
Air flow falls below (real problem level)	Shut down electronics and air cooling system Inform user of shutdown and the problem
FC-17 flow rises above (spec) or falls below (spec)	Warn user of occurrence
FC-17 flow falls below (real problem level)	Shut down electronics and liquid cooling system Inform user of shutdown and the problem
Add in humidity and pressure sensors	x