Sandia Aerospace SAFE 328 - Manual (Page 6)

2.5 Calibration
No calibration of the SAFE 328 is required. The unit is tested by slowing the fan manually and observing
a high on the Fan Fail pin . Allow the fan to return to normal speed and observe a low on the Fan Fail
pin.
2.6 Continued Airworthiness
Maintenance of the SAFE 328 is on condition only. No scheduled maintenance is required.
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2.4 Electrical
The SAFE 328 operates on 28Vdc. It will provide a low on the Fan Fail pin (center pin) of the connector when
operating normally. When airflow drops to 65% of nominal, as determined by fan RPM, the Fan Fail pin will
output a high. An external pull-up is required. Power to SAFE 328 can be supplied from the aircraft buss or from
the unit to be cooled if an output is available. If connected to the aircraft buss, the SAFE 328 should be protected
by a 1.0 amp fuse or breaker.