[j-nsp] Power failure - unexpected?

[Stacy W. Smith]

You might want to look at sections 2.12 and 17 of this web-based  
training course:

http://www.juniper.net/training/elearning/m320.html

My understanding is that three of the four AC power supplies must be  
on to power a fully populated router.  I don't think there's specific  
information on how many components can be installed in a chassis with  
only two AC power supplies.

--Stacy

On Apr 5, 2007, at 9:05 AM, Raniery Pontes wrote:

>
> Thanks for the reply.
>
> The "problem" is we´re using AC power supplies and documentation for
> these modules (thanks Steinar) is less detailed than for DC power
> suplies. In my case it seems it doesn´t matter *which* module is  
> turned
> off (differently from DC power suplies).
>
>  From the same doc:
> "A minimum of three AC power supplies provides full power  
> redundancy.If
> one power supply fails or is removed, the remaining power supplies
> instantly assume the entire electrical load. Two power supplies  
> provide
> the minimum configuration with full power for as long as the router is
> operational."
>
> The last sentence is really unclear to me. I still don´t know in what
> FPC/PICs/hardware combinations I can turn off 2 power supplies without
> turning off the router.
>
>
> Raniery
>
>
> James Cornman escreveu:
>> From what I recall, The m320 in DC mode, power supply 1 is  
>> redundant for
>> supply 0, and 3 for supply 2. So assuming you have a redundant power
>> supply powered for your maintenance, it should not have caused an  
>> issue.
>> Meaning, if you have 0 and 2 powered, and powered off 1 or 3, it  
>> should be
>> fine. The power layout on the M320 is a bit confusing and i've gotten
>> caught with this same problem. Certain aspects of the chassis are  
>> powered
>> by the 2 sets of power supplies. Meaning if you turn off power  
>> supplies 2
>> and 3, your SIB/SFM modules could lose power, or FPCs in slots 4  
>> thru 7 or
>> something could lose power. I'm not sure of the exact specifics, the
>> document that was linked earlier can help.
>>
>>
>> Good luck
>>
>> On Thu, 5 Apr 2007, sthaug at nethelp.no wrote:
>>
>> | >   we´ve got an M320 with 4 power modules, a single routing  
>> engine and
>> | > the following FPC´s:
>> | >
>> | > 1 FPC type 1 (with 2xGigE)
>> | > 1 FPC type 2 (with 3xOC-48)
>> | > 1 FPC type 3 (with 2x10GE)
>> | >
>> | > During a maintenance, we had to turn off only 2 power modules,  
>> but
>> | > unfortunately the whole box went down ...
>> | >
>> | > According to docs, I was expecting the router to stay up and  
>> running,
>> | > once this is not a fully "loaded" router (without lots of FPC  
>> type 3,
>> | > for instance).
>> | >
>> | > What went wrong ? ;)
>> | >
>> | > Are there circumstances where I can turn off 2 power modules  
>> and M320
>> | > stay running?
>> |
>> | It depends on type of power module (AC or DC) and *which*  
>> modules you
>> | remove. An M320 can operate with two out of four DC power  
>> supplies (we
>> | have verified this):
>> |
>> | http://www.juniper.net/techpubs/hardware/m320/fru-m320-dc-power- 
>> supply.pdf
>> |
>> | and from what I can see, it can also operate with two out of  
>> four AC
>> | power supplies:
>> |
>> | http://www.juniper.net/techpubs/hardware/m320/m320-ac-power- 
>> supply-fru/m320-ac-power-supply-fru.pdf
>> |
>> | Steinar Haug, Nethelp consulting, sthaug at nethelp.no
>> |
>> | _______________________________________________
>> | juniper-nsp mailing list juniper-nsp at puck.nether.net
>> | https://puck.nether.net/mailman/listinfo/juniper-nsp
>> |
>>
>
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