3-phase power quality analysers offer high accuracy

9th October 2006

ES Admin

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Carlo Gavazzi has introduced a range of three-phase power quality analysers offering the highest class of accuracy, available as either standalone instruments - model WM5 96 - with a backlit liquid crystal display, or the PQT H transducer version. These new utility-grade analysers are powered by ARM RISC processors, which significantly speeds up signal processing and data communication compared with existing instruments.

Both WM5 96 and PQT H are designed for demanding applications, coming with revenue grading and approval. They are also suitable for billing purposes thanks to their 0.2 accuracy class and compliance with standards including ANSI/IEEE C12.20-1998 and CAN3-C17-M84.

The new analysers continuously monitor harmonic content (up to the 63rd harmonic) of current and voltage levels together with all other electrical parameters. Monitoring of up to 16 different electrical parameters is supplied by alarm set-points with a specific logic (OR/AND), and by automatic recording of up to 10.000 events (alarm, min, max, digital input status, reset). Operators can monitor anomalies in installation and loads in real time, enabling them to promptly determine and plan the necessary maintenance actions, thus avoiding possible damage to loads and eliminating the need for costly unscheduled stoppages.

User features include powerful functions for complex and comprehensive tariff management, such as the ability to set 12 tariffs by 24 time periods/day. Extended load or line control is provided by asymmetry, phase sequence and phase loss functions on up to 16 selected variables, linked to as many as 16 independent or OR/AND/OR+AND logic controlled alarms.

The standalone instrument's front panel offers an optical communication port based on the ANSI C12.18 protocol, enabling quick and simple communication with a PC or laptop. Bundled software enables users, through a multi level login procedure, to view measurement data and display them as a matrix on the monitor. Operators can quickly and easily adapt the instrument to individual applications by programming a range of parameters. Through this communications port they can download stored events (alarm, min, max, digital input status, reset) in standard spreadsheet format, recalibrate the instrument as required, and upgrade the analyser firmware to take advantage of future enhancements.

Other interfaces include up to 12 digital inputs, 16 pulse outputs, eight analogue outputs, RS232 and RS485 serial communications.

Environmental protection is provided up to IP20 for the transducer version; and IP65, NEMA4x and NEMA12 for the WM5 models.