Owners Manual

Figure 11. AC PSU status indicator
1. AC PSU status indicator/handle
Table 12. AC PSU status indicator codes
Power indicator codes Condition
Green A valid power source is connected to the PSU and the PSU is operational.
Blinking amber Indicates a problem with the PSU.
Not illuminated Power is not connected to the PSU.
Blinking green When the firmware of the PSU is being updated, the PSU handle blinks green.
CAUTION: Do not disconnect the power cord or unplug the PSU when updating
firmware. If firmware update is interrupted, the PSUs do not function.
Blinking green and turns
off
When hot-plugging a PSU, the PSU handle blinks green five times at a rate of 4 Hz and turns off.
This indicates a PSU mismatch with respect to efficiency, feature set, health status, or supported
voltage.
CAUTION: If two PSUs are installed, both the PSUs must have the same type of label;
for example, Extended Power Performance (EPP) label. Mixing PSUs from previous
generations of PowerEdge servers is not supported, even if the PSUs have the same
power rating. This results in a PSU mismatch condition or failure to turn the system
on.
CAUTION: When correcting a PSU mismatch, replace only the PSU with the blinking
indicator. Swapping the PSU to make a matched pair can result in an error condition
and unexpected system shutdown. To change from a high output configuration to a
low output configuration or vice versa, you must turn off the system.
CAUTION: AC PSUs support both 240 V and 120 V input voltages with the exception of
Titanium PSUs, which support only 240 V. When two identical PSUs receive different
input voltages, they can output different wattages, and trigger a mismatch.
CAUTION: If two PSUs are used, they must be of the same type and have the same
maximum output power.
CAUTION: Combining AC and DC PSUs is not supported and triggers a mismatch.
18 PowerEdge R740xd system overview