1/2018 | MONITOR | 17 quickly and easily through the display of form abbrevia- tion, measured value and unit. The homepage displays four measurement parameters which the user can select individually. A vector diagram and a harmonic histogram enable initial assessment of the current system status. Navigation is based on a software-assisted 4-button con- cept, i.e. the button function is adapted to the context of the respective menu. This in turn makes quick, intuitive operation possible, immediately and without a long familiarisation period. The PEM353 measures all significant power quality parameters such as • THD (Total Harmonic Distortion), TOHD (Total Odd Harmonic Distortion), TEHD (Total Even Harmonic Distortion), TDD (Total Demand Distortion) • Individual harmonics up to 31st order • k-factor, peak factor and power factor • unbalance. A clear overview of the system is provided at all times The integrated limit value monitoring defines an individ- ual system status and raises an alarm when deviations occur. The operator is alerted to the situation on site by a flashing display. Alarm relaying can be assured via the communication interface and also using digital outputs, e.g. with transfer to a PLC (programmable logic control- ler). Violations of limit values are logged in the internal event memory. The fourth current input can be used either to monitor the central earthing point (CEP) or for N-conductor measurement. This enables any possible overload of the N conductor to be detected at an early stage by 3n-harmonics. This reduces the risk of fire, and the risk of overvoltage on single-phase consumers, which may result from a break in an N-conductor. In the context of energy data monitoring, the PEM353 provides the essential measurement quan- tities for real energy, and does so with outstanding accuracy (Class 0.5). The package is completed with recording of daily energy values for the preced- ing two months and monthly energy values for the preceding three years. Active, reactive and apparent energy levels are counted for each phase, and as a cumulative value. This means that one device can record up to three single-phase resources. Additional meters for active and reactive energy separate the energy flow into import, export, total and net energy. If the sourcing of energy is dependent on tariffs, each of the afore- mentioned energy meters is available in up to eight different tariffs. Other types of energy, e.g. meters for compressed air, water and gas, can be integrat- ed and accommodated via digital inputs and pulse counters. The comprehensive equipment features of the PEM353 make it suitable for use as a data supplier for applications such as power quality monitoring and energy data monitoring, and it also serves to improve reliable plant availability by monitoring the N-conductor or the CEP. INFO More information: Applications and fields of application • Modern display instrument for electrical quantities • Power quality monitoring, limit value monitoring and alarm relaying • N-conductor measurement and monitoring/monitoring of the CEP • Energy measurement and energy data monitoring. Dipl.-Wirtsch.-Ing. Tobias Weiberlenn Dipl.-Ing. Sandra Schiffke