Every electrical component can produce EMI when energized. Electromagnetic compatibility issues in the form of Electromagnetic interference is caused by the voltage and current in the form of electric and magnetic fields. Depending on the strength of the fields, EMI can degrade or disrupt the performance of other devices. As power increases, the EMI can increase and if not considered in the design and installation of a device, significant problems can result. Some equipment intentionally produces emissions, such as cellular telephones and radio transmitters, while other equipment, such as computers, fluorescent lights, power lines and variable frequency drives produce unintentional emissions, so they’re referred to as incidental radiators.
Jim Phillips, P.E. – June 2006 – NEC Digest
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