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Friday, September 27, 2013

Manufacturing Process Unexpectedly Halted

This medium-sized manufacturing facility, located in an industrial park that experienced an unexplained shutdown of several adjustable speed drives (ASDs) , wreaking havoc on key process equipment. Each day, at approximately 6 am, the utility-owned PF capacitor kicks on to improve the voltage of inductive loads prevalent in many of the park’s manufacturing facilities. The ASDs are conditioned to anticipate this expected power quality event and are typically able to ride through the problem. So when one of the ASDs closed down and interrupted the continuous stream manufacturing process, the facility manager needed to learn why, correct the problem, and prevent it from happening again.

As you can see from the attached screen capture, a second, unanticipated capacitor switching event occurred shortly after the first. This event was categorized by the Encore Series System Capacitor Switching Answer Module , enabling the facility manager to pinpoint the exact source of the problem. Further analysis showed that the ASD shutdown was the result of an overcurrent trip, which was quickly remedied preventing hours of downtime, at a loss of $10,000/hour.

Friday, September 20, 2013

SecuTest & SecuLife Safety Testers From Gossen Metrawatt

The SecuTest SIII+ and the SecuLife ST are universal test instruments for testing the electrical safety of portable electrical equipment in commercial, residential, and medical applications operating at 120V/60Hz or 230V/50Hz.  The SecuTest SIII+ and SecuLife ST are the same basic instrument, with the SecuLife including standard features specific to medical testing, such as testing up to 10 application parts and test sequences per IEC 60601.  In order to evaluate electrical safety, tests are performed for protective conductor connections, insulation resistance, and leakage current.  Individual tests can be performed manually, or testing can be automated by using built-in test sequences that are in accordance with widely accepted international standards.

In the video below, Dieter Feulner, Product Manager for Gossen Metrawatt,  tests for touch current on a mobile X-ray device.

Friday, September 6, 2013

Dranetz Fall Power Quality Seminars

The first Dranetz Fall Power Quality Seminars have been confirmed and we hope you can attend.

These no-cost educational seminars are held at select cities in the continental US throughout the year. This incredible value is open to anyone interested in Dranetz instruments, and only requires registration to reserve your seat. All power quality seminars are 1/2 day and run from 8:00am to 12:00 noon, and a continental breakfast is included.
To register online CLICK HERE.

The current schedule (with more to follow) is:
October 9, 2013
Mayfield Village, OH

October 22, 2013
Albuquerque, NM

October 23, 2013
Lake Oswego, OR

October 23, 2013
Birmingham, AL

October 24, 2013
Greenwood Village, CO

October 30, 2013
Fort Lauderdale, FL

November 6, 2013
Fargo, ND

November 7, 2013
Bismarck, ND

November 13, 2013
Waltham, MA

General Agenda

  • Introduction to Monitoring
  • What Are We Measuring?
  • Transducer Considerations
  • Introduction to Power
    • Energy and Demand, Power Factor 
    • Real-Apparent-Reactive Power
    • Typical Utility Billing Practices
    • Case Study — determining energy costs
  • Going Beyond Energy and Demand 
    • to Improve Reliability
    • Introduction to Power Quality
    • Impact on Business Productivity
    • Maintenance and Operating Costs
    • Identify Typical Power Quality Events (overview of sags, transients, harmonics, etc.)
  • Q & A: Your Application Questions
Ready to register?  CLICK HERE

Wednesday, September 4, 2013

Automatic Distribution Fault Location Case Study

Consolidated Edison Company of New York is a long time user of Dranetz power quality monitoring systems and sister company Electrotek Concepts software and services. Dranetz Encore Series (61000) and Enhanced Power Quality, EPQ DataNodes) and legacy power quality instruments (8010 PQNode) are deployed throughout their network collecting needed data for PQ assessment. Electrotek’s PQView software, which is seamlessly integrated with the Encore System, provides database management, reporting and advanced statistical analysis. PQView’s Fault Analysis Modules identify and characterize faults, providing location information. Alarms are sent to operators who dispatch crews for repair, reducing the time to locate faults by hours.
The automatic distribution fault location system at the Consolidated Edison Company of New York was first put into use during the spring of 2005. It incorporates power quality monitors, microprocessor relays, database applications, up-to-date distribution circuit models, and geographic information system (GIS) databases in order to provide automatic distribution fault identification and fault location estimation. The system has become an indispensable tool for quickly and accurately identifying the location of faults in the Con Edison network distribution system.
The fault location system uses measurements recorded by Encore Series PQ monitors located in distribution substations. These measurements are downloaded automatically by Encore Series Software which manages the power quality monitoring system. Fault data is automatically acquired by PQView software and stored in its relational database. Calculations on these measurements estimate the reactance from the substation to the fault. The calculations are based on phasor measurements derived from the voltage and current samples and calibration constants based on previous fault data and known locations. The result of these calculations is an estimated “reactance to fault,” or XTF. The XTF values are compared with feeder models that estimate the positive-sequence impedance between substation and feeder structures. The estimated locations can be viewed in tabular format on the corporate intranet and can be displayed graphically using maps derived from a GIS database. The estimations for fault location typically are available on the company intranet approximately ten minutes after the fault’s occurrence. The estimates are accurate to within 10% of the total number of feeder structures, for about 80% of the single-phase faults measured in the system.
Each Dranetz power quality monitor records voltage and current at the output of a transformer in parallel with other transformers that together supply up to thirty underground network distribution feeders.
Example of a single phase fault on Con Edison network estimated to be j0.97 ohms downline from monitored substation

Example Summary Page for Faults Measured in a Network

Example Map Display of Estimated Fault Location