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MX960 DC Power Supply

In the DC power configuration, the router contains either two or four DC power supplies (see Figure 1), located at the lower rear of the chassis in slots PEM0 through PEM3 (left to right). You can upgrade your DC power system from two to four power supplies. The DC power supplies in slots PEM0 and PEM2 provide power to the lower fan tray, DPC slots 6 through 11, and SCB slots 1 and 2. The DC power supplies in slots PEM1 and PEM3 provide power to the upper fan tray, DPC slots 0 through 5, and SCB slot 0.

Four power supplies provide full redundancy. If a DC power supply fails, its redundant power supply takes over without interruption.

For existing power supplies, each DC power supply has a single DC input (–48 VDC and return). For high-capacity power supplies, each DC power supply has two DC inputs (–48 VDC and return).

The minimum number of power supplies must be present in the router at all times. See Table 1 for the minimum required number of power supplies.

Table 1: Minimum Required Number of DC Power Supplies
Router Model Configuration Minimum Required Number of Power Supplies Model Number


High-capacity DC

One per zone x two zones = 2 power supplies



Normal-capacity DC



Figure 1: DC Power SupplyDC Power Supply
Figure 2: High-Capacity DC Power SupplyHigh-Capacity DC Power Supply

Each high-capacity DC power supply supports two DC feeds. You must set the input mode switch according to the number of DC feeds available for the power entry module(PEM). The input mode switch positions 0 and 1 indicate the following:

  • Position 0—Indicates that only one DC feed is provided.

  • Position 1—Indicates that two DC feeds are provided.