Juniper PWR-MX960-4100-AC-S network switch component Power supply

In AC power configurations, the router contains three or four AC power supplies, located at the rear of the chassis in slots PEM0 through PEM3 (left to right). Each AC power supply provides power to all components in the router.

In normal-capacity configurations, when three power supplies are present, they share power almost equally within a fully populated system. Four AC power supplies provide full power redundancy. If one power supply fails or is removed, the remaining power supplies instantly assume the entire electrical load without interruption. Three power supplies provide the maximum configuration with full power for as long as the router is operational.

Each AC power supply has a corresponding AC appliance inlet located in the chassis directly above the power supply. Each inlet requires a dedicated AC power feed and a dedicated 15 A (250 VAC) circuit breaker.

In high-capacity power supply configurations, the power supplies are zoned. No current sharing between power supplies is needed with the upgraded system because the redundancy changes from 3+1 per system to 1+1 per zone. For MX960 AC configurations, two zones are present. Two adjacent power supplies need to be installed in the chassis with two feeds attached.

High-capacity AC power supplies in slots PEM 0 and PEM 2 provide power to the lower fan tray, DPC slots 6 through 11, and SCB slots 1 and 2. The high-capacity AC power supplies in slots PEM 1 and PEM 3 provide power to the upper fan tray, DPC slots 0 through 5, and SCB slot 0.

Each high-capacity AC PEM accepts two AC feeds in two unique AC receptacles. The high-capacity AC PEM is equipped with a DIP switch that can be set according to the number of AC feeds that are present for the PEM.

- Position-0 indicates that only one AC feed is provided
- Position-1 indicates that two AC feeds are provided

Verify that the DIP switch settings on the high-capacity AC PEMs are set according to the number of feeds that are present.