Test Systems

Power quality measuring systems with integrated fault recorder for professional power quality analysis

Whatever processes are currently underway in a power system, the power quality analysers of the EPPE series will register even minor disturbances or alterations. All the parameters of an electrical supply system are recorded continuously and precisely. Detailed quality evaluations reveal even the slightest of deviations and help identify the cause of disturbances. Precise time synchronization of the measuring systems via GPS allows the measured data from a number of different devices to be consolidated in order to comprehensively monitor an entire supply system. EPPE systems continuously capture all power system parameters for the analysis and documentation of power quality to standards defined by the individual user or international standards such as EN 50160 or IEC 61000. High storage capacities and effective data compression methods enable long-term recordings to be made over periods of up to several years. As well as continuously recording all the quantities relevant to power quality, the integrated fault recorder module allows the event-triggered capture of transient processes with sampling rates of up to 30 kHz

Multi-functional measurement technology for fully automatic power monitoring

EPPE CX and EPPE PX are powerful, multi-functional measuring instruments for comprehensive, continuous and fully automatic power monitoring at all voltage levels. Various different types of signal inputs for voltages and currents as well as optional sensor inputs and outputs make the devices extremely flexible to use. EPPE CX | PX can be tailored to meet the individual needs and requirements of the user. The applications listed below are given as examples of the wide range of different uses of the devices:

  • Power quality analysis
  • Power quality monitoring
  • Differential current measurement
  • Fault analysis n Measurement of harmonics
  • Monitoring and analysis of renewable power systems
  • Network optimisation
  • Load management
  • Monitoring to EN 50160
  • Fault location
  • Trend recording
  • Critical load monitoring
  • Consumption measurements, e.g. for load optimisation

Product overview

EPPE CX Stationary, fully automatic monitoring system for panel mounting

EPPE CX is ideal for fully automatic monitoring with continuous measurement data transfer to a central data system. Evaluation is performed automatically and a builtin alarm system informs the employees responsible should a fault occur.

EPPE PX The portable solution in a carrying case

EPPE PX has been specially developed for mobile measurements and installation monitoring. Sensor inputs, direct inputs for current measurement and galvanically isolated voltage inputs make the device extremely flexible to use. The rugged carrying case protects the measuring device even in harsh environmental conditions.

Operating concept

Operation via touch screen

The device can be operated easily using the ergonomic touch screen. All functions and measured value displayscan be selected directly from the main menu. All important measured values and status information can be seen at a glance. Alternatively, the device can also be operated with the aid of the function keys.

Limit value violations and fault records can be displayed and analysed directly on the screen of the EPPE PX, allowing on-site analysis at the measurement location without a PC.

Operation and management via PC

As well as using the touch screen, it is also possible to operate and configure EPPE CX and PX with the ergonomic and easyto-understand software for Windows® operating systems. The EPPE operating software also contains comprehensive analysis functions for the evaluation of the measurement data. Fully automated operation is also possible, including fault analysis, evaluation in accordancewith selected standards(e.g. EN50160), report creation, export functions and message management.

Time synchronization

Power quality analysis and fault analysis with full area coverage call for precise time synchronization. Only when measured values are recorded by a number of devices absolutely simultaneously, is it possible to compare them with one another and analyse them correctly. EPPE CX | PX can use the following methods of time synchronization:


  • GPS
  • DCF77
  • IRIG-B
  • Synchronisation to PC time
  • Seconds and minutes pulse
  • KoCoS-Interlink interface


  • GPS
  • DCF77
  • Synchronisation to PC time
  • KoCoS-Interlink interface

Recording functions

Power quality recording

The continuous recording of all power system parameters allows comprehensive power quality analysis to DIN EN 50160 or quality criteria defined by the individual user. Characteristic values are captured and calculated to IEC 61000-4-30 class A, IEC 61000-4-7 and IEC 61000-4-15. Because quality reports can be evaluated and created automatically as PDF files, it is easy to provide proof of quality whenever required, even without specialist knowledge.

Continuous data recording

The data logger function records measurement data continuously. The recorded data can be downloaded to a centralcomputer without interrupting the measurement. As a result, data can be recorded continuously for a number of years. The averaging intervals can be configured in line with individual requirements. For each averaging interval, the mean value for the given time and the highest and lowest single RMS values for a system cycle are recorded with an exact time stamp. Long-term recordings provide comprehensive information on the entire power system, expose slow changes, as can result from a changing load or generator structure, and reveal potential for energy savings.

Event recording

Event recording provides information on the time, level and duration of limit value violations and a classification of events to EN 50160, for example. If required, the event signatures can also be recorded with a time resolution of half a period.

Fast fault recording for power system faults

When a limit value violation occurs, all analog and binary signals are recorded with a configurable resolution of 100 Hz to 30 kHz. The recording comprises separately configurable time windows for pre-fault, fault and post-fault periods. The fault recording duration can either be set to a fixed length or can be controlled by the actual duration of the event.

Slow fault recording

In addition to the analog and digital signals which are measured directly, the RMS fault recorder can also record all the quantities calculated on the basis of these signals, such as frequency, unbalance, positive sequence system, negative sequence system and zero sequence system, active power, reactive power and apparent power, harmonics etc. The sampling rate can be set between 1 Hz and double the system frequency (100 Hz/120 Hz). The recording is ideal for detecting and assessing slow processes, such as power swings, or for generator monitoring.

Recording of digital events and states

Binary inputs are primarily used to read in signals from protection relays, circuit breaker positions or machine conditions, for example, which are of decisive importance for the analysis of fault records. The binary inputs can also be used to trigger fault records in order to obtain a high-resolution record of the state of the power system at the moment of switching.

Energy meter

Power consumption can be monitored using the built-in energy meter with accuracy class 0.2S and optimised with the aid of long-term trend analysis. Active, reactive and apparent energy can be recorded and analysed extremely precisely.


Power system quality analysis

Power system and power quality analysis can also be carried out automatically to the selected standard (e.g. EN 50160). A number of analysis tools are provided for this purpose:

  • Slow changes with trend analysis
  • Event recording with signature display
  • Flicker analysis
  • Harmonic analysis
  • Analysis of interharmonics
  • Event classification and assessment (UNIPEDE, ITIC, etc.)
  • Graphical display of extreme value duration distribution
  • Table overview of limit value violations
  • User-defined limit value and analysis settings
  • Automatic generation of weekly, monthly, quarterly and annual reports
  • Calculation and signal display for differential current measurements
  • Useful zoom functions and variable scaling
  • Superimposition of different signal characteristics
  • Formulary and formula editor for the calculation of further power system quantities

Evaluation of fault records

The software also contains a comprehensive range of powerful analysis tools for the assessment of fault records:

  • Vector displays
  • Harmonic analysis on the basis of full waves or to IEC 61000-4-7 with interharmonics
  • Freely configurable absolute and delta measurement cursors
  • Useful zoom functions and variable scaling
  • Simultaneous display, superimposition and synchronization of more than one fault record
  • Formulary and formula editor for the calculation of further power system quantities
  • Individual report creation using the clipboard
  • Automatic report creation