Die meisten Einrichtungen mit hoher Zuverlässigkeit investieren erheblich in USV-Systeme, Generatoren und andere Schadensbegrenzungsgeräte, um zu verhindern, dass sich Stromversorgungsprobleme auf ihr Geschäft auswirken. Jedoch, Bei diesen Schadensbegrenzungsgeräten und zugehörigen Geräten handelt es sich um komplexe elektromechanische Systeme, die selbst fehleranfällig sind und häufig keine Alarme oder Benachrichtigungen auslösen, wenn sie nicht gemäß den Herstellerspezifikationen funktionieren. Hier kommt die kontinuierliche Energieüberwachung ins Spiel.
Systeme zur Überwachung der Stromqualität Kontinuierliche Bewertung des Zustands der Stromversorgung an wichtigen Stellen innerhalb einer Anlage, einschließlich der Stromversorgung, Generatoren, USV-Eingänge und -Ausgänge sowie andere kritische Verteilungspunkte und Lasten. These systems have been proven to prevent problems from occurring by proactively detecting anomalies in the electrical supply before they escalate into system failures. These systems are invaluable for troubleshooting failures should they occur as well as monitoring demand, energy and environmental parameters like temperature and humidity.
The ideal time to install any electrical equipment, including power monitoring equipment, is during the initial construction phase. An often overlooked benefit of these monitoring systems is they can be an extremely valuable asset that can be used during site commissioning. During this phase the entire facility is put through its paces with each element being thoroughly tested to validate the design, see if equipment is operating to manufactures/designers specifications and that it is compatible with the overall facility. Power monitoring systems can provide significant added value not only by recording and documenting the successful commissioning of a facility but also in identifying and resolving any system failures that occur at this critical phase.
A large worldwide cable television and media company recently constructed and commissioned a state-of-the art data center and production facility. During construction, Dranetz’s Encore Series, a permanently installed power quality monitoring system was installed to monitor 25 key locations within the data center. Monitored locations include each utility feed, Generatoren, inputs and outputs of each UPS and critical PDU’s downstream from the UPS. Encore Series was chosen for many reasons including state-of-the-art power quality capabilities, ease of use, web browser interface and cost vs. the competition.
Wanting to take full advantage of its benefits, Encore Series was an integral part of site commissioning with recorded data continually being evaluated and compared to expected results. Among many items, the commissioning procedures included tests to evaluate the source transfer from utility (one of two utility supplies) to generators then back to utility. Unlike other test performed, this transfer test failed multiple times with the facility remaining dark and the test uncompleted as failures were detected prior to completion. Zwischen den Tests wurden Liniendiagramme überprüft und mit dem tatsächlichen Aufbau verglichen, um die ordnungsgemäße Installation und Konstruktion der Geräte zu überprüfen und so die Ursache des Problems zu lokalisieren. Diese Auswertung ergab, dass mehrere zugehörige Leistungsschalter entweder ausgelöst oder in der falschen Position waren. Der letzte Testversuch erwies sich als weitaus schwerwiegender, da ein Leistungsschalter völlig ausfiel und sichtbare Schäden sowie Rauchgeruch auftraten.
Die Daten der Encore-Serie wurden vor Beginn der Abnahmeprüfungen vor Ort auf forensische Beweise für diesen Fehler überprüft. Das Überwachungssystem war so konzipiert, dass kritische, für diesen Test wichtige Stellen instrumentiert wurden und äußerst wertvolle Daten lieferten, die zu einer schnellen Diagnose dieses Problems führten. Jeder Generatorbus (Generator 1, Generator 2) und Nutzfutter (Utility 1, Utility 2) was monitored and waveshapes recorded at locations Generator 1 and Utility 2 at the time of the last test that resulted in the breaker failure.
A close inspection of the current waveforms recorded at both Generator 1 (3000A bus) and Utility 2 (4000A bus) locations provided a key indicator of the source of the problem. Current measurements at each location were many times higher than the rated bus capacity. Tatsächlich, current waveshapes on all phases were clipped indicating a saturation of current transformers (CT’s) as a result of currents well in excess of their specifications.
The data above quickly led the team to closely review the sequence of events leading up to, and resulting from the failure at these locations. As suspected, Generator 1 and Utility 2 buses were connected together as shown in the diagram below at the time of failure. Being out of phase the resultant current draw on the system caused the related breakers to trip and ultimately led to the failure of the Generator 1 breaker. Further investigation indicated a sequencing problem in the programmable logic controller (PLC) allowing the Generator 1 and Utility 2 breakers to be closed at the same time. A programming error in the PLC was determined to be the ultimate source of the problem. The programming error was corrected, the failed breaker repaired and the tests were then successfully performed.
“Encore Series paid for itself today” commented the facility manager. Having a power quality monitoring system oversee site commissioning helped this facility very quickly resolve a critical path failure with minimal impact on the overall schedule. In diesem Fall, the payback for the system was less than 1 month!
Quelle:
Dranetz
1000 Neue Durham Road, Edison, NJ 08818
Gebührenfrei: 800-372-6832
Telefon 732-287-3680