Description

This article describes the issue of the MPC 3D 16x10GE card not powering up in certain slots on an MX960 router.

Symptoms

The MPC 3D 16x10GE card does not power up in certain slots on an MX960 router.

Solution

This issue is due to power zones. The PEMs are divided into two zones - Zone 0 and Zone 1 . Zone 0 contains PEM 0 and PEM 2 and Zone 1 contains PEM 1 and PEM 3 . Each zone can only produce a certain amount of power, depending on the PEM type (AC or DC) and the number of feeds that it has.

If you try to install a component that exceeds the remaining power, then the PEMs will not be able to power up the component. So how to identify how much power is available in the zone and if the component is exceeding it?

The first and easiest method to identify the power output and zone capacity issues is via the following command:

> show chassis power
The output will be as follows:
PEM 3:
State: Online
DC input: OK (1 feed expected, 1 feed connected)
DC input: 48.0 V input (48000 mV)
Capacity: 1700 W (maximum 4100 W)
DC output: 432 W (zone 1, 9 A at 48 V, 25% of capacity)

System:
Zone 0:
Capacity: 1700 W (maximum 4100 W)
Allocated power: 1670 W (30 W remaining)
Actual usage: 912 W
Zone 1:
Capacity: 1700 W (maximum 4100 W)
Allocated power: 1613 W (87 W remaining)
Actual usage: 902 W
Total system capacity: 3400 W (maximum 8200 W)
Total remaining power: 117 W
In the above output, you can view the output capacity for the PEMs, the number of feeds for the PEM, and the amount of power currently being used in each zone.

How to identify which components are powered by which zone?

Zone 0 powers the following components:

  • Lower fan tray

  • FPC slots 6-11

  • SCB 1 and 2

Zone 1 powers the following components:

  • Upper fan tray

  • FPC slots 0-5

  • SCB 0

How much power does each component need?

  • Base System - 50W (split between each zone; 25W per zone).
  • Fan Trays - 640W (320W per zone per fan tray).
  • MPC - 440W (each). (Note: 100gig cards use 610W each.)
  • SCB0 + RE0 = 240W.
  • SCB1 + RE1 = 240W
  • SCB 2 = 150W

How much power can each PEM type produce?

  • MX960 AC normal-capacity
1700W
  • MX960 AC high-capacity
1 Feed - 1700W
2 Feed - 4100W
  • MX960 DC normal-capacity
2800W
  • MX960 DC high-capacity
1 Feed - 1700W
2 Feed - 4100 W


You can determine the amount of allowed and remaining power in each zone by first adding up the power that is available per zone, based on the PEM type. You should then add up the power consumption in each zone, based on the components that are installed in the zone.

This will indicate the amount of current power consumption and subtracting it from the first sum will provide the total available remaining power. So, if the remaining power in Zone 1 is 320W and you are trying to install a MPC 3D 16x10GE card in slot 3, it will not power up. The required power for this card is 440W and it exceeds the remaining 320W.

For more information about component power requirements and power calculations, refer to the following link:

www.juniper.net/techpubs/en_US/release-independent/junos/topics/reference/specifications/calculating-power-requirements-mx960.html


If you have determined that the MPC not powering up is not due to a power zone issue (for example, it powers up in another slot in the same zone or more than enough remaining power is available to meet the component needs), then open up a case with JTAC, as this might indicate an issue with the specific slot on the chassis.