EMC

EMC measuring devices

Many factors determine the quality of communication in industrial networks. While some of these factors are tangible, such as the cabling or the cable length, others can only be recorded using special measuring devices, such as electromagnetic influences.

Often underestimated as one of the most common causes of errors in machine and system downtimes, the risk of sporadic system failures due to electromagnetic interference increases with the increasing degree of automation. Increased control frequencies and dynamics in data exchange contribute to the fact that it is becoming more and more complex to guarantee electromagnetic compatibility (EMC) in networked production.

"Leakage currents," a term to describe currents that flow via undesired paths outside of the laid lines, are among the most disruptive factors for stable EMC. For example, when a voltage is induced in the shield of an adjacent network cable via the magnetic field around a live motor line, this is the case. If this is not earthed on both sides, the shield current is usually diverted via the connected device and affects components and electronics. In the long run, this will also impair the quality of communication in the network. For the detection of the screen and leakage currents in the frequency band of 50/60 Hz and 5 Hz-1 kHz, Indu-Sol recommends the leakage current clamp EMCheck® LSMZ I.

Interactions between power supply and control technology often lead to sporadic disruptions, which is why long-term monitoring makes sense. The EMCheck® ISMZ I clamp is the ideal measuring device for this. It records all line-bound interference currents for up to 14 days and can also be used in an environment that is severely affected by interference. To check the quality of the installed shielding and earthing measures on a system is in accordance with standards, metrological evidence of good equipotential bonding has to be provided. An extensive set of different EMC measuring devices is not required for this. The EMCheck® MWMZ II measuring clamp is sufficient, which, if needed, also determines the shield loop resistance of bus or measuring system cables and resistances in return current paths.

Indu-Sol has developed the EMV-INspektor® V2 for permanent monitoring of electromagnetic influences and disturbances. The diagnostic device can measure current and frequency along network cables, via the 24 VDC supply, via the 230/400 VAC low-voltage distribution system, in the equipotential bonding system, and via the encoder lines. The recording and analysis are possible in parallel at four measuring points, contactless and without interruption. Individual quality parameters can be assigned to each channel so that maintenance staff can carry out a specific condition assessment. The INspektor® is a suitable tool to permanently avoid EMC disturbances in the automation environment with its functions.