Arista PWR-511-AC-RED 500W AC Power Supply — Red Label Forward Airflow, Hot-Swappable PSU

The red-label PWR-511 supply that keeps forward-airflow Arista switches redundant.

The Arista PWR-511-AC-RED is a 500W AC power supply for 1RU Arista switches that use the PWR-511 series. Its red label marks forward (front-to-rear) airflow, and it accepts 100–240V AC input and supports hot-swap redundancy. It suits data center teams maintaining Arista top-of-rack switches.

Color-Coded Airflow Prevents Costly Cooling Mistakes

In a busy rack, it is easy to install a power supply with the wrong airflow direction. The PSU fan then fights the switch fans, internal temperatures rise and the switch may log alarms or throttle.

Arista color-codes PWR-511 supplies to prevent this. The red-label PWR-511-AC-RED uses forward airflow, so it matches switches with red-coded fan modules. A quick visual check confirms the match before installation.

Hot-Swap Redundancy for Top-of-Rack Switches

Most 1RU Arista switches run two PSUs. If one fails, the other carries the full load; the PWR-511-AC-RED then replaces the failed unit without a reboot or traffic interruption.

Universal AC Input

The supply accepts 100–240V AC, so the same part works in data centers worldwide. It connects with a standard IEC power cord and reports status to the switch for monitoring through EOS.

Setup Instructions

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

1. Confirm the part number is listed as supported for your Arista switch, and confirm the fan modules carry the same red (forward 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.