Power Supply Basics

Safety Standards for EMI/EMC filters

Posted by Dulcie on August 18, 2015
Posted in: Power Supply Basics

Safety standards for EMI/EMC are different than those used with power supplies. The International Electrotechnical Commission (IEC) has published IEC 60939-1, but as of March 2015, the standard IEC 60939-1 has not been formally adopted globally.

Europe has adopted the standard with EN 60939 – relating to “passive filter units for electromagnetic interference suppression for use within, or associated with, electronic or electrical equipment and machines”.

In the USA, UL 1283 is the standard – “requirements cover electromagnetic interference (EMI) filters installed on, or connected to, 1000 V or lower potential circuits, 50 – 60 Hz, or up to 1500V dc, and installed in accordance with the National Electrical Code”.

Even Canada with CSA C22.2 No.8 has a different standard – applying to “applies to filters intended for suppressing electromagnetic interference in, or with, apparatus and machines that are to be connected to an ac supply with nominal system voltages of up to 750V and a nominal frequency of up to 60 Hz or connected to a dc supply up to 1060 V dc, intended to be used in nonhazardous locations in accordance with the Canadian Electrical Code, (CEC) Part I”.

Canada and the USA are cooperating on safety certifications and the cULus recognised logo can be seen on filters along with the European certified test houses (TUV, VDE, NEMKO, SEMKO, DEMKO, ENEC and others).

Fig 1

What will not be present is the CE mark as filters are excluded from the current EU directives, as they are classified as components.

For more visit www.emea.lambda.tdk.com/uk/safety