Loose Bus Bar Bolts Cause Sags

Published by Dranetz – BMI Case Studies An administration building in a government complex in New Jersey had a transformer with a 4KV primary, 120/208V wye, 800A secondary. The buss duct ran up to a second-floor panel, which supplied an office area. Computer misoperations and lights flickering were occurring randomly for nearly two years. EmergencyContinue reading “Loose Bus Bar Bolts Cause Sags”

Textile Industry Evaluation

Published by Dranetz – BMI Case Studies Despite their differences, continuous-process industries share underlying characteristics: they maintain continuous operations in facilities that represent substantial start-up costs and time but can be interrupted or disrupted by seemingly minor fluctuations in power quality. If the product stream is disrupted, lost productivity and lost product can create aContinue reading “Textile Industry Evaluation”

Thumping Sounds in the Closet

Published by Dranetz – BMI Case Studies Elevator control panels for the lower zone mid-rise elevators were on the nineteenth floor of a forty-story office building in a large midwestern city. It was fed with 480V transformer on the same floor, with the feeders to the controls rated at 800A. Excessive noise and vibration ofContinue reading “Thumping Sounds in the Closet”

The Case of the Missing Contact

Published by Dranetz – BMI Case Studies Executive SummaryDefiance Metal Products Company contracted with Electrotek Concepts to perform field measurements of their welding operations, and to make recommendations for remediation of Power Quality problems at the facility. The customer has been experiencing both major and minor electrical problems. The minor problems include occasional observable flickerContinue reading “The Case of the Missing Contact”

Computer on Shared Branch Circuit

Published by Dranetz – BMI Case Studies Engineering laboratory adjacent to offices. A computer system used by laboratory personnel exhibited intermittent failures and data errors. Typically, these would start around 10 a.m. On some days there were no failures. A power monitor was installed at the panelboard serving the computer system. The monitor was connected,Continue reading “Computer on Shared Branch Circuit”

Manufacturing Process Unexpectedly Halted

Published by Dranetz – BMI Case Studies 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 inContinue reading “Manufacturing Process Unexpectedly Halted”

Utility Power Factor Capacitor Bank Switch Problem

Published by Dranetz – BMI Case Studies A medical clinic in Las Vegas, Nevada, employing sensitive computed tomography (CT Scan) system. Power was brought to the system from a 480 volt service feeding a 480-to-208 volt isolation transformer. CT Scan system was experiencing repeated computer lockups and component failures. The medical equipment service company installedContinue reading “Utility Power Factor Capacitor Bank Switch Problem”

Elevator Control Problem

Published by Dranetz – BMI Case Studies Newly constructed condominium building in Westchester County, NY. The condominium developer could not get the necessary permits for operation because the two building elevators would not run on the building’s emergency back-up generator. The problem was originally diagnosed as excessive voltage drop between the main service entrance inContinue reading “Elevator Control Problem”

Harmonic Distortion of Current

Published by Dranetz – BMI Case Studies Office building with personal computers, terminals, copiers, and other electric office equipment supplied by three-phase wye service. Facility engineers at this site experienced repeated problems with the failure of electrical distribution equipment. A distribution transformer overheated and failed, circuit breakers were tripping, and electrical connectors were burning out.Continue reading “Harmonic Distortion of Current”

Impact of Thunderstorms

Published by Dranetz – BMI Case Studies As the first thunderstorms of the season begin to roll through, it is important to safeguard your facility’s equipment against the significant damage that can be caused by the high frequency transient energy of lightning strikes. The first step is to make sure that you power monitor isContinue reading “Impact of Thunderstorms”