EMC for Functional Safety & Risk Management
EMC & Compliance Information > EMC for Functional Safety & Risk Management
Functional Safety is part of the overall safety of a system that depends upon the correct functioning of electrical and/or electronic equipment. All electronic equipment (hardware and/or software) is vulnerable to certain electromagnetic disturbances (electromagnetic interference EMI). The aim of these guides is to provide a non-exhaustive range of techniques and measures that can address the interfering effects of EMI that a safety related system could experience over its complete life cycle. When competently selected and applied, a set of such techniques and measures will provide part of the evidence required for Functional Safety arguments and for compliance with IEC 61508. (intro from IET web site).
EMC Functional Safety & Risk Management.
The first guide on this subject was written by Keith Armstrong's IET Working Group in 2008. The original article was first published in Issue 78 of The EMC Journal (past issues are in the archive on this site).
Publishers of the Journal, Nutwood UK Limited (also founders of the EMCIA) were licenced by the IET to publish a hard copy of the first guide.
The latest documents are provided on this page. Other information can be found on the IET Web Site. Click Here.
EMC for Functional Safety, IET 2008. Click Here.
Overview of techniques and measures related to EMC for Functional Safety, IET 2013. Click here
Introductory managers guide to EMC for Functional Safety, IET 2013. Click here
Here are three papers on this subject,presented at the IEEES's 2016 EMC Symposium in Ottowa:
How to Manage Risks with Regard to Electromagnetic Disturbances. Click here
Non-Standardized Immunity Test Techniques to Help Manage Risks caused by EM Disturbances. Click here
Why is the IEEE Developing a Standard on Managing Risks Due to EM Disturbances? Click here
Medical EMI Risk Management.
There is a great deal more to complying with the latest version of the medical EMC standard, IEC 60601-1-2 Edition 4:2014, than just testing in an EMC laboratory!
The device manufacturer also has to document a lot of design and verification details concerning the management of safety risks that could be caused by EMI, and this work cannot be done by an EMC test laboratory. See the following workshop presentation for a quick overview of what is required:
Medical EMC: Risk Management of Electromagnetic Disturbances, IEEE 2016 EMC Symposium, Ottawa Click Here
An important issue concerning IEC 60601-1-2 Edition 4:2014:
Previous editions of IEC 60601-1-2, up to Edition 3:2007, covered both EMC and (what we might call) “EMC-Safety” at the same time, allowing compliance with them under the Medical Device Directive to exempt a medical device from also having to declare compliance with the EMC Directive.
However, IEC 60601-1-2 Edition 4:2014 is only concerned with safety risk management issues. Complying with it only covers the “EMC-safety” requirements of the Medical Device Directive, and does not permit exemption from having to comply with the EMC Directive as well.
The IEC team that created Edition 4:2014 was well aware of this, and so created the new standard IEC TR 60601-4-2:2016 – a test standard that copies the EMC test methods in Edition 4:2014 very closely so that it is possible to perform just one set of EMC laboratory tests to satisfy the testing requirements of both IEC 60601-1-2 Ed.4:2014 (“EMC-safety”) and IEC TR 60601-4-2:2016 (EMC).
This one set of tests covering both of these standards, plus the additional work on risk management by the manufacturer that is required by IEC 606061-1-2 Edition 4:2014, would once more allow compliance with the Medical Device Directive to provide exemption from the EMC Directive, without adding significant testing time and cost.
However, it is important to understand that IEC TR 60601-4-2 is a TR and so cannot be listed in the OJEU under any Directives. So it would have to be used as part of a 'technical file' compliance argument under the Medical Devices Directive.
An alternative would be for a medical device to be EMC tested using the relevant standards listed in the OJEC under the EMC Directive, for example the appropriate generics (IEC 61000-6-x) for emissions and immunity, plus IEC 61000-3-2 and -3. This would probably then require a declaration of conformity to the EMC Directive, as well as to the Medical Device Directive.