Arista PWR-511-AC-BLUE 500W AC Power Supply — Blue Label Reverse Airflow, Hot-Swappable PSU

The blue-label PWR-511 supply for Arista switches cooled rear-to-front.

The Arista PWR-511-AC-BLUE is a 500W AC power supply for 1RU Arista switches that use the PWR-511 series. Its blue label identifies reverse (rear-to-front) airflow, and it supports 100–240V AC input and hot-swap redundancy. It suits deployments where switch ports face the rear of the rack.

Matching Airflow to Rack Orientation

Top-of-rack switches are often mounted with their ports facing the rear of the rack to line up with server connections. In that orientation, the switch must pull air from the PSU side and exhaust it at the port side.

The PWR-511-AC-BLUE provides that reverse airflow. Paired with blue-label fan modules, it keeps cool air moving through the switch in the right direction and prevents hot spots and temperature alarms.

Blue Label for Quick Verification

Arista’s color coding lets technicians confirm airflow at a glance: blue for reverse, red for forward. Matching the PSU and fan colors before installation avoids cooling conflicts.

Redundant, Hot-Swap Operation

With two supplies installed, the switch keeps forwarding traffic if one fails. The PWR-511-AC-BLUE slides into the empty bay and starts sharing load immediately, restoring redundancy without downtime.

Setup Instructions

How to Replace an Arista PWR-511-AC-BLUE

1. Confirm the part number is listed as supported for your Arista switch, and confirm the fan modules carry the same blue (reverse airflow) marking.
2. If the device has a second working power supply, leave it running; otherwise schedule a maintenance window and power the device down.
3. Disconnect the AC or DC cord from the failed unit, release the latch and slide it out, then slide the new module into the empty bay until it locks.
4. Connect the power cord, check that the PSU status LED turns green, and confirm in the device CLI or management interface that the supply reports OK.