PDU Circuit Breaker Overview
Each PDU contains six circuit breakers, one for each outlet group. These circuit breakers are safety devices to protect components from damage and you from personal injury. A circuit breaker trips and shuts the power off to an outlet group when it detects an overloaded circuit, a short circuit, or another fault condition.
When operating normally in the On (|) position, the circuit breakers are flush with the side of the PDU. When tripped to the Off (0) position, the circuit breakers extend beyond the side of the PDU.
In the modular system, because there is not sufficient room for resetting the breakers by hand, a special PDU circuit breaker reset tool is provided. Use this tool to reset a PDU circuit breaker from the rear of the modular system.
Note - If a PDU breaker trips, all nodes using that breaker are affected.
Each node has two power supplies: PS0 and PS1. From the rear view of the modular system, the PS0 is connected to the left PDU, and the PS1 is connected to right PDU. When a PDU breaker trips, all of the PSUs in that breaker group lose power, generating a failure event.
LEDs for all nodes experiencing a failed PSU have the amber service light on. The system management software detects the PS0 or PS1 failed state, then lights the Major System Fault LED and sends out both events and alarms to its clients. See Modular System LEDs.
 | Caution - To prevent injury and component damage, always determine the cause of a tripped circuit breaker before resetting it. |