National Instruments RMX-4120 User Manual page 49

Chapter 2 Basic Functions
Overheat Protection (OHP), Overheat Protection2 (OHP2)
This protection function is activated when the RMX programmable power supply internal
temperature rises to an abnormal level. Abnormal temperature levels can occur under the
following conditions:
• When used in an environment outside its operating ambient temperature range
0°C (32°F) to 50°C (122 °F)
• When used with its air inlet and exhaust port blocked.
• When the fan motor has stopped.
Figure 2-21. Alarm Indication when OHP2 has been Activated
If OHP2 is activated, turn the POWER switch off and on.
If you do not fix the problem that caused the OHP or OHP2 to be activated, OHP or OHP2 will
be activated again even if you restart the RMX programmable power supply.
Fan Failure Protection (FAN)
This function is activated when the number of fan rotations drops to an abnormal level.
Figure 2-22. Alarm Indication when FAN has been Activated
Incorrect Sensing Connection Protection (SENSE)
This function is activated when the remote sensing cables are connected with the incorrect
polarity (positive or negative), and the remote sensing function is then used.
Figure 2-23. Alarm Indication when SENSE has been Activated
Low AC Input Protection (AC-FAIL)
This function is activated when a low AC input is detected.
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