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Power supply MX240 configuration

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  • 1.  Power supply MX240 configuration

    Posted 09-18-2018 02:16

    Hello,

     

    I have an MX240 with two PEMs, located at PEM0 and PEM1:

     

    • PEM 0:
      State: Online
      AC input: OK (1 feed expected, 1 feed connected)
      Capacity: 1590 W (maximum 1590 W)
      DC output: 200 W (zone 0, 4 A at 50 V, 12% of capacity)
    • PEM 1:
      State: Online
      AC input: OK (1 feed expected, 1 feed connected)
      Capacity: 2050 W (maximum 2050 W)
      DC output: 696 W (zone 0, 12 A at 58 V, 33% of capacity)
    • PEM 2:
      State: Empty
      Input: Absent
    • PEM 3:
      State: Empty
      Input: Absent
    • System:
      Zone 0:
      Capacity: 1590 W (maximum 1590 W)
      Allocated power: 1040 W (550 W remaining)
      Actual usage: 896 W
      Total system capacity: 1590 W (maximum 1590 W)
      Total remaining power: 550 W

     

    Is it the correct location if I need redundancy?

     

    Regards.



  • 2.  RE: Power supply MX240 configuration

     
    Posted 09-18-2018 03:55

    For AC power supplies if your power source is 110v then you need two supplies for basic operation and they would be in slots 0 & 1 as you have them.  In this case there is no redundancy.  You would need 4 power supplies for that and install in all 4 slots.

     

    If you have 220v feeds for the power supplies you can have redundancy with just two power suppliies and they would be installed in slots 0 and 2.

     

    https://www.juniper.net/documentation/en_US/release-independent/junos/topics/concept/hardware-redundancy-mx240.html

     



  • 3.  RE: Power supply MX240 configuration

    Posted 09-18-2018 04:44

    Thanks, but we have the power supplies in PEM0 and PEM1 and a short time ago a power broke down and the chassis continued working correctly which leads us to think that we have electrical redundancy. Our power supplies part number is 740-022697, is it possible?



  • 4.  RE: Power supply MX240 configuration

     
    Posted 09-18-2018 04:50

    For full dual feed redundancy you need to have power supplies in at least 0 and 2.

     

    What matters for AC power supplies is the feed size.  For AC supplies you may need all 4 if the power feeds are 110v and not 220v.

     

    All the details are here.

    https://www.juniper.net/documentation/en_US/release-independent/junos/topics/concept/hardware-redund...

     



  • 5.  RE: Power supply MX240 configuration

    Posted 09-19-2018 00:06

    Thanks for your reply.

     

    Our AC power supplies are 220v. When we use "show chassis hardware" command we can see PS 1.2-1.7kW; 100-240V AC in and when we use "show chassis power" command we can see Capacity:  1590 W (maximum 1590 W).

     

    Also, our AC power supplies are in PEM0 and PEM1 and according to the documentation that you have give us, for redundancy, the AC power supplies should be in PEM0 and PEM2 so, if we keep them in PEM0 and PEM1 and fail the PEM0 we will not have redundancy?



  • 6.  RE: Power supply MX240 configuration

     
    Posted 09-19-2018 04:39

    Juniper AC power supplies are what is called universal supplies.  They work if they are connected to either 110 or 220 feeds.

     

    The question is for the electrical panel input feed to the power supply.  Is the eletrical feed sending 110 or 220 volts to the power supply?

     

    If you are connected to 220 volt feeds then you install in pem 0 and pem 2 for full redundancy.

     

    If you are connected to 110 volt feeds you need 4 power supplies for full redundancy and use all 4 slots.  If you only have two 110 feeds you need to use both pem 0 pem1 for full power to both power zones of the mx240.

     



  • 7.  RE: Power supply MX240 configuration

    Posted 09-19-2018 23:49

    Thanks for your reply.

     

    Is there any way to watch the feed using commands?



  • 8.  RE: Power supply MX240 configuration
    Best Answer

     
    Posted 09-20-2018 04:35

    Not that I have found.  The detail command does show the feed voltage for DC supplies but I could not find a command to show the voltage input value on the ac supplies.  

     

    You will need to check with the facilities group at the site to see if the circuits are 110 or 220.

     



  • 9.  RE: Power supply MX240 configuration

    Posted 09-25-2018 05:08

    Thank you very much.



  • 10.  RE: Power supply MX240 configuration

     
    Posted 09-30-2018 23:54

    Power Calculator Beta version is good tool to get some rough value of the box load w.r.t power

     

    https://apps.juniper.net/power-calculator/