Re: OOT:Power Quality in Data Center

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
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Sat Dec 26 2009 - 16:27:29 ART