Posts Tagged ‘electrical’

Sensors

Thursday, October 8th, 2009

Since I’m on the subject of facility, I might as well cover a few more points on data center facility, measurement and sensors.  When I think about sensors, it reminded me of my first job.  I used to be with a Systems Integrator, working on Plant Information Management Systems (PIMS) for refineries, gas plants, utilities, etc.  I remember once, I was 120km west of Doha, Qatar, and was commissioning the PIMS system together with my customer and main contractor. It was August, in the mid-90’s.  We were going through the screens and data points / tags with values collected from field instruments in the plant via their Distributed Control System (DCS).

Operator-Console As we review the data points, we came across a few thermocouples out in the plant indicating measurements of 54′C to 60′C.  Although it was a hot summer day, a reasonable reading for those tags should be in the range of 45′C to 50′C.  It was an interesting anomaly…

For a gas plant, it is very critical that the plant data collected are accurate as the data are used for planning purposes, production controls, yield accounting, and many other forms of analysis.

For a data center, data accuracy is also equally important.

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Capacity Planning: Big Rocks, Little Rocks story

Saturday, September 26th, 2009

In our daily life, we deal with recurring capacity problems day in and day out. Planning for capacity allocation, whether in our personal lives or at work, is a mix of science, art, guess works and perhaps some level of luck too. This is the same whether it is for sizing up physical compute and data arrays for a virtualized environment and likewise, for data center facilities.

Michael Manos wrote an interesting piece around data center capacity planning (entitled “Chiller-side Chats: The Capacity Problem“) and provided a very impartial explanation to bridge the understanding between IT, data center manager and the business around this complex subject. In Manos’ blog, he elaborated using an example of planning the power allocation and distribution in a data center.  (more…)

Minimizing UPS and Gen-Set Incompatibility

Monday, September 21st, 2009

diesel_genset

Found this interesting article (entitled Minimizing UPS and Gen-Set Incompatibility) explaining about compatibility issues with UPS and gensets, primarily due to:

  • Failure of the UPS to acquire and accept power from the gen-set,
  • Instability of the gen-set frequency or voltage when powering the UPS,
  • Inability of the UPS to synchronize its output to the gen-set,
  • Inability to enable the operation of the maintenance bypass circuit,
  • Excessive output voltage distortion, and
  • Power transfer issues.

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