4–12
DECbridge 500/600 Series Problem Solving
The power supply also provides the following features:
4.3.5.1
Power Supply Shutdown
If an overvoltage condition occurs at any of the power-supply outputs, the entire
power-supply shuts down. The power supply outputs become latched and will NOT
automatically recover even if the cause of the overvoltage condition is removed. To
reset the supply and resume normal operation, you must cycle power by removing ac
power to the unit, waiting at least 10 seconds, then reapplying the ac power.
4.3.5.2
Thermal Protection
If the temperature inside the power supply is too high for normal operation, the pow-
er supply protects itself by shutting down. When the overtemperature condition is
corrected and the unit cools off, cycle the ac power input (as described in the previous
paragraph) to reset the supply and resume normal operation.
4.3.5.3
DC OK Output Signal
The DC OK signal from the power supply controls the DC OK LED on the AP mod-
ule. It is asserted (and the LED is on) when all the voltages (including the fan voltage)
meet predetermined minimum thresholds:
•
+5 Vdc output is above +4.5 Vdc
•
+12 Vdc output is above +11 Vdc
•
–12 Vdc output is below –11 Vdc
•
+12 Vdc fan output is above +10 Vdc
