The Case of the Missing Contact

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 flicker in the overhead HID lighting system. TheContinue reading “The Case of the Missing Contact”

Computer on Shared Branch Circuit

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, line-to-neutral (Channel A) and neutral-to-ground (Channel B).Continue reading “Computer on Shared Branch Circuit”

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. TheContinue reading “Manufacturing Process Unexpectedly Halted”

Utility Power Factor Capacitor Bank Switch Problem

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 installed a power monitor on site to analyzeContinue reading “Utility Power Factor Capacitor Bank Switch Problem”

Elevator Control Problem

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 in the basement and the tenth floor motorContinue reading “Elevator Control Problem”

Harmonic Distortion of Current

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. These problems are all symptomatic of overloadContinue reading “Harmonic Distortion of Current”

Impact of Thunderstorms

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 is up to the job and is capableContinue reading “Impact of Thunderstorms”

Service Area Flicker

An entire service area of a Midwest facility. The utility was receiving complaints of annoying light flicker from an entire neighborhood. When the utility connected a power monitor to the 240V distribution bus the problem was quantified. The RMS Voltage event summary, Figure 1, indicates the bus voltage was essentially constant until a load wasContinue reading “Service Area Flicker”

Major Health Care Center

Severe power quality problems damaged X-ray equipment, costing $100,000 in one instance. The source of the problem was the switch over from utility to generator power, during regular testing and emergency situations. Figure 1(below) identified the cause of the problem, an out-of-phase transfer, captured by On Power with a Dranetz 658 Analyzer. Figure 1 Ideally,Continue reading “Major Health Care Center”

Stalled Motors

In this case study, we look at an industrial customer with two 1250hp motors on a 4kV circuit, whose motors would not start. To determine the problem, we installed a Dranetz – BMI PP4300 at the motor input. The power monitoring instrument quickly identified the motor itself as the source of the problem. In fact,Continue reading “Stalled Motors”