The UMD 709 is a compact high-end power quality meter for DIN rail mounting. It measures 4-phase current and voltage with up to 3 tariffs in 4-quadrant operation in class 0.05 and thus the work in class 0.2s, as well as all common mains quantities, e.g. harmonics up to the 128th harmonic. With the 5th connection, residual currents can be measured continuously. The unit maps the mains quality according to EN 50160, EN 61000-2-2, EN 61000-2-4 and EN 61000-2-12. It has a large 512 MB memory. The unit can be accessed via the Ethernet interface and live measured values can be viewed via the associated web server using a web browser. This means that Internet protocols such as NTP can also be read in and PLC systems and building management systems can be easily connected. Digital inputs/outputs and a serial RS485 interface are integrated.are integrated. With the firmware module GO, oscilloscope functions for current and voltage are activated and trigger signals for limit value events are set. With the PQ S software module, the power quality is continuously recorded and evaluated.
The unit is used for continuous monitoring of voltage quality in data centres, buildings or at power supply companies. Furthermore, the UMD 709 is used with a corresponding residual current transformer for the detection of residual currents/differential currents.