Re: OOT:Power Quality in Data Center

thanks all for the feedback

this is a new building, not designed for DC actually.

i spent my days from DC to DC.
as usual when my laptop touchpad went crazy,

we just yell customer to check their power
they will fixed it.
i dont need to replace my rack-pdu or switches

but this time
the power vendor who responsible for this building
dont get it
a yell is not enough

looks like i need to hire independent power expert to talk to them

one of them try to install separate grounding cable for my rack-pdu
and it solved the problem
but the other guy told him that is dangerous
grounding should be consolidated
at this point i believe my gears have no problem

yes the building has UPS as well

On 12/27/09, Keegan.Holley_at_sungard.com <Keegan.Holley_at_sungard.com> wrote:
> My thoughts exactly. Aside from the threat of death most major cities
> have laws governing what must be done by a certified electrician. So if
> you cause an issue you might get your company fined. A friend of mine had
> to pay an electrician $240 to turn a tripped breaker back on. Beyond
> making sure what I was given matches what's in the instructions that came
> with whatever I'm plugging in I generally stay away from this stuff. Are
> you sure you're not overdrawing whatever they are giving you? Usually if
> there's a PDU in each rack there are two power feeds and two UPS's
> (usually the dumpster sized thing near a wall). Does everything have dual
> power supplies? Have you tried testing devices on one feed at a time? I
> suppose you could even put in your own low cost UPS's (one for each feed),
> but if your hosting provider can't give you clean power and doesn't know
> what to do when you bring it up I'd probably be shopping for another.
>
>
>
>
> From:
> Christopher Copley <copley.chris_at_gmail.com>
> To:
> ospfv2 <ospfv2_at_gmail.com>
> Cc:
> Cisco certification <ccielab_at_groupstudy.com>
> Date:
> 12/24/2009 02:33 PM
> Subject:
> Re: OOT:Power Quality in Data Center
> Sent by:
> <nobody_at_groupstudy.com>
>
>
>
> Depends on that you define as quality power. There are a few ways to
> define
> that...
> 1. How clean is your power (conditioning)
> 2. Constant flow from a commercial source
> 3. Back up power operations
>
> The above are just a few things that can fall in that definition.
> You can always get an amprobe, and that can tell you your amperage,
> voltage,
> watts, etc. I personally have an amprobe and a device called a killowatt.
> (
> http://www.thinkgeek.com/gadgets/travelpower/7657/ ) But you really need
> to understand electric to understand what it is all telling you.
>
> As a Cisco tech I personally would recommend to a client to call a
> certified
> electrician, one that specializes in data center power. Depending on how
> larger the Data Center is they might have an electrician on call. (it is
> better to let a rack of gear fail, than to kill your self)
>
> My personal saying IMHO, if you do not understand electricity don't even
> pretend to talk to a client about it or even touch it EVER. Typically
> Data
> Centers have high voltage feeds to most racks (120 and above)
>
> I can not stress it enough... It is a VERY VERY VERY dangerous thing and
> can
> bit you hard and fast in many many many ways. I work for an power
> distribution manufacturer and nearly every employee is an electrical
> engineer or certified electrician, and they always stress, let the pro's
> handle the stuff that can kill you.
>
> Please keep in mind this is all IMHO,
>
> HTH
> Chris
>
>
>
> On Thu, Dec 24, 2009 at 1:45 PM, ospfv2 <ospfv2_at_gmail.com> wrote:
>
>> the scenario
>>
>> you arrived in data center,
>> you plug your laptop adaptor into rack PDU,
>> your touch-pad pointer going crazy.
>> so you grab a usb-mouse & connect it to your laptop.
>>
>>
>> then your cisco switch doesn't function properly,
>> it was ok when you configure it in the office.
>>
>> have you ever encounter this issue ?
>>
>> some people told me it was harmonic problem
>> some said it was grounding problem
>> any idea ?
>> is there any tools to measure the power quality
>> before the customer ask me to replace the whole rack and switches
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
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>
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Received on Sun Dec 27 2009 - 23:58:17 ART