Normal-Capacity Ac Power Supplies; High-Capacity Ac Power Supplies - Juniper MX960 Hardware Manual

Normal-Capacity AC Power Supplies

The MX960 can be powered by three normal-capacity AC power supplies (non-redundant configuration)
or four normal-capacity AC power supplies (redundant configuration). In a non-redundant configuration,
the three AC power supplies share power almost equally within a fully-populated MX960 system. In a
redundant configuration there is full power redundancy meaning if one power supply fails or is removed,
the remaining power supplies instantly assume the entire electrical load without interruption and provide
full power for the maximum configuration for as long as the router is operational.
NOTE: Each normal-capacity power supply must be connected to a dedicated AC power feed
and a dedicated customer site circuit breaker. Juniper recommends that you use a 15 A (250 VAC)
minimum, or as required by local code.

High-Capacity AC Power Supplies

The MX960 can also be powered by two high-capacity AC power supplies. The high-capacity power
supplies must be installed in adjacent slots in the chassis. They can operate in one-feed mode or two-feed
mode. The maximum inrush current for a high-capacity AC power supply is 38A per feed at 264VAC.
In one-feed mode, the power supplies output power at a reduced capacity (1700W). In two-feed mode,
the power supplies provide power at full capacity (4100W). To operate the MX960 at full capacity, you
must use two-feed mode. High-capacity power supplies require one power cord per feed. Therefore, to
operate the MX960 at full capacity, you will need four power cords.
Each high-capacity AC power supply accepts two AC feeds in two unique AC receptacles, one receptacle
located on the chassis and the other on the power supply.
When using the high-capacity AC power supplies in one-feed mode, plug one end of the power cord into
the corresponding AC receptacle directly above the power supply in the chassis and the other end into a
AC outlet. When using the high-capacity power supply in two-feed mode, you need two power cords.
Plug one power cord into the AC receptacle on the chassis and then plug the other end into a AC outlet.
Next, plug the second power cord into the AC receptacle on the AC power supply and plug the other end
into a AC outlet.
In high-capacity AC power supply configurations, there are two zones that provide power to specific
components in the MX system. No current sharing between power supplies is needed with the high-capacity
system because the redundancy changes from 3+1 per system to 1+1 per
the components that receive power for each zone in a high-capacity AC power supply configuration.
zone.Table 64 on page 135
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