Technical Documentation
MX480 DC Power Supply LEDs
Each DC power supply faceplate contains three LEDs that indicate the status of the power supply (see Table 1). The power supply status is also reflected in two LEDs on the craft interface.In addition, a power supply failure triggers the red alarm LED on the craft interface.
 | Note: An SCB must be present for the PWR OK LED to go on. |
Table 1: DC Power Supply LEDs
Label | Color | State | Description |
|---|---|---|---|
PWR OK | Green | Off | Power supply is not functioning normally. Check the INPUT OK LED for more information. |
On | Power supply is functioning normally. | ||
Yellow | On | The main output voltage is out of range (lower limit: 37.5 V to 39.5 V; upper limit: 72.5 V to 76 V). | |
BRKR ON | Green | Off | DC power supply circuit breaker is turned off. |
On | DC power input is present and the DC power supply circuit breaker is turned on. | ||
INPUT OK | Green | Off | DC input to the PEM is not present. |
On | DC input is present and is connected in correct polarity. | ||
Yellow | On | DC input is present, but not in valid operating range or connected in reverse polarity. |
