Re: OT: servers vs. lightning and power outages
Dan Ritter put forth on 3/18/2011 12:13 PM:
> On Mon, Mar 14, 2011 at 09:40:34PM -0500, Stan Hoeppner wrote:
>> Jerome BENOIT put forth on 3/14/2011 7:58 PM:
>>
>>> Just curious:
>>> why the UPS must be at the bottom ?
>>
>> Your attempt at being a smart ass aside, I'll answer your question. The
>> answer, however, isn't the simple one you're expecting.
>>
>> I stated bottom of the server rack explicitly because some SAs install
>> all of their UPS gear in a single dedicated rack, or two, or xx, and
>> feed PDUs in their server racks, often ignorantly over loading their UPS
>> output circuits in the process. And yes, these SAs will load a 42U rack
>> bottom to top with UPS units. I had to do this on one occasion myself
>> due to an ill conceived pre-existing equipment layout. Thankfully the 4
>> Liebert 3000s I had to mount in the top of the UPS rack only weighed
>> about 80 lbs apiece. The first one was tough, but the last 3 were
>> relatively easy. Ego boost prize goes to the first OP to reply
>> correctly explaining why this was the case.
>
> You needed several hands to hold the first Liebert in place as
> you screwed it into the rack.
I actually only needed two hands (plus a knee and then a shoulder) for
the first unit, as I'm a bit larger than the average guy. I do seem to
recall a little grunting was involved. ;) Once I had my left shoulder
under the front edge and my left hand under the middle, I was able to
get the first screw in pretty easily. With half the weight relieved the
other screw went in very smoothly.
> The next one could rest on top of the first.
You win the ego boost prize. :) The 2nd one went smoothly, and the 3rd
and 4th were slightly tougher due to holding ~80 lbs overhead, however
brief that period was. If I weren't 6'4" 200 lbs. I'd have never
dreamed of making this a one man job. My boss at the time was about
5'4" and 130 lbs. He couldn't even lift one of the Lieberts off the
ground. Coincidentally, this is why all the rackable UPS units were on
the ground to begin with. The previous and existing staff were unable
to lift them, even working as a team.
> I note that Liebert does not offer a slide-in rail kit.
They do offer slide rail kits today
http://www.emersonnetworkpower.com/en-US/Products/ACPower/RackmountUPS/Documents/SL-23180.pdf
http://www.emersonnetworkpower.com/en-US/Products/ACPower/RackmountUPS/Documents/SL-23185.pdf
though I don't know if they did when the 3000s I was installing were
originally purchased. Rails aside I thought they were decent UPS units.
The 3000s we had were online models, not line interactive, so battery
life was lower than the typical line interactive models most shops deploy.
--
Stan
Reply to: