UMG 103
(Universal measurment device for Din Rail)

Universal measurement device for DIN rails

Universal measuring devices of the UMG 103 product family are mainly designed for use in low voltage distribution systems.

UMG 103
Harmonics occur due to operating equipment with a non-linear characteristic, e.g. transformers used in saturation, energy saving bulbs, frequency converters and power electronics. They cause a load on the mains due to additional currents and can affect or even destroy operating equipment. This mains feedback can be detected and documented using power quality analysers.
Modbus Interface
Many UMG measuring devices have an RS485 interface with a Modbus RTU protocol, which enables extremely cost-efficient networking. It features simple topology configuration and a lack of sensitivity to EMC interference. Communication between the sender and the recipient takes place on a wired basis via a sheathed, twisted pair cable.
GridVisĀ® is a comprehensive and scalable piece of software for setting up an energy monitoring system and monitoring the power quality. It is used to both program and configure many UMG measuring devices, as well as to read, process and analyse the measured data. Typical applications are energy supply, industrial systems, facility management, etc.
Accuracy of Measurement
The high accuracy of measurement is due to the high sampling rate and very good long-term stability. If used as intended (ambient temperature!), accuracy of measurement is always better even after years of use than that of conventional meters immediately after delivery. Devices that are certified according to class A are available for measuring tasks that are particularly demanding.

  • Protocols: Modbus RTU / Slave

  • RS485

Power Quality
  • Harmonics up to 25th order, odd harmonics
  • Unbalance
  • Distortion factorTHD-U
  • Distortion factorTHD-I
Accuracy of Measurement
  • Energy: Class 0.5 (... / 5 A)
  • Current: 0.5 %
  • Voltage: 0.2 %

  • N, TT networks

Network visualisation software
  • GridVisĀ®-Basic (in the scope of supply)

Areas of Application
  • Measurement and checking of electrical characteristics and energy consumption in energy distribution systems
  • Cost centre management
  • Threshold value monitoring, measured value transducer for building management systems or PLC
  • Monitoring of harmonics


Universal measuring devices of the UMG 103 product family are mainly designed for use in low voltage distribution systems.

  • "3 Voltage measurement inputs (300 V CATIII)"
  • "3 Current measurement inputs"
  • "3-Phase or 3 x Single-Phase-Measurement possible"
  • Measurement of the reactive distortion power
  • Continuous sampling of voltage and current measurement inputs
  • "Sampling frequency 5.4 kHz"
  • Transfer of the measured values via a serial interface
  • "Supply voltage via measurement voltage L1-N, L2-N and L3-N"
Power Quality
  • Harmonics analysis up to 25th harmonic,Odd harmonics
  • Unbalance
  • Distortion factorTHD-U /THD-I
  • Minimum and maximum Values
  • Measurement of positive, negative and zero sequence component
Fig GridVis Harmonics analysis-FFT
Technical Overview
Accuracy Of measurement Network
1.Energy: Class 0.5 (./ 5 A) N, TT-networks
2.Current: 0.5 %
3.Voltage: 0.2 %

Communication Interface
Protocols: Modbus RTU / Slave RS485
Network Visualization Software

Gridvis Basic (Scope of supply)

Dimension Diagrams(in mm)
Janitza UMG103 Massbild
Typical Connections
Janitza UMG103 Anschlussvariante-en