[j-nsp] MX960 PEMs and 3 phase power

[Gert Doering]

Hi,

On Thu, Mar 23, 2023 at 06:01:07AM +0200, Mark Tinka via juniper-nsp wrote:
> If you are in a typical data centre, all your power is going to come 
> from at least one UPS anyway, maybe even two. So not sure you need to 
> worry about this.

"typical" data centres over here have 2 primary feeds, either one
with UPS and one with generator, or both with (different) UPSes - but
depending on the load drawn by a rack, might be presented as multiple
circuits with 16A each, and individual circuit breakers.

Now, if another device next to your MX960 has a PSU failure and kicks
one of the circuit breakers, what do you want your MX960 to do...  as
well, what do you want to happen if the UPS fails, and one of the primary
feeds goes down.

We do not have MX960s, but we did have other devices with 3 PSUs that
needed 2 to fully power all line cards, and this was quite a bit annoying
- "it says redundant PSUs, but no full feed A / feed B resiliency"...

gert
-- 
"If was one thing all people took for granted, was conviction that if you 
 feed honest figures into a computer, honest figures come out. Never doubted 
 it myself till I met a computer with a sense of humor."
                             Robert A. Heinlein, The Moon is a Harsh Mistress

Gert Doering - Munich, Germany                             gert at greenie.muc.de
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 630 bytes
Desc: not available
URL: <https://puck.nether.net/pipermail/juniper-nsp/attachments/20230323/436f720d/attachment.sig>