Electromagnetic compatibility – is there a compliance issue?

May 11th, 2017, Published in Articles: EE Publishers, Articles: EngineerIT


The SABS technical committee TC73 oversees electromagnetic compatibility (EMC). Its business plan states: “Growing use of the available frequency spectrum for various communication purposes requires increasing control over interference and emissions from all types of equipment.” Available expertise is fragmented and there are insufficient measures to ensure conformance with regulations. The business plan was approved in 2014 and is now being relooked at amidst concerns over the rapid increasing radio frequency (RF) noise floor levels, the emergence of the internet of things (IoT) devices and increasing noncompliance to standards.

One of the issues is that while it is widely stated that the RF noise floor is increasing there is no actual measure of how much it has increased and at what rate. Several organisations including the International Telecommunications Union, the USA’s FCC and some European regulators are working on this. It is well understood that improved compliance with EMC standards will go some way in solving the problem.

There are many questions around EMC issues. The urgent question emerging is: What is being done to develop a culture of compliance to EMC standards? If compliance is followed, the problem of an ever increasing RF noise floor would be at least partially addressed. EngineerIT invited industry to comment on a number of the issues.

Do you share the concern that EMC compliance is an increasing problem? If so, what, in your view, are the consequences of non-compliance?

Praneel Ruplal, ICASA

Praneel Ruplal, senior manager: Engineering Facilities and Research, the Independent Communications Authority of South Africa (ICASA): “Non-compliance to EMC standards is a problem. The increased proliferation of RF devices has led to the EMC environment become increasingly cluttered. ICASA has to ensure that these devices can co-exist in an interference-free manner. The emergence of the IoT, machine-to-machine communications (M2M), power line communications (PLC), wireless power transfer (WPT) and wearable technologies creates a greater potential for harmful interference to radio services. To that end, ICASA is active in several standardisation activities, including the International Special Committee on Radio Interference (CISPR). The CISPR is a specialised Committee of the International Electrotechnical Commission (IEC) that is responsible for developing EMC standards. The standards are intended to protect radio reception in the range 9 kHz to 400GHz from interference caused by operation of electrical or electronic appliances and systems in the electromagnetic environment. CISPR develops technical standards that aim to protect radio reception in the range 9 kHz to 400GHz from interference caused by operation of electrical or electronic appliances and systems in the electromagnetic environment. These standards are useful and of importance to the authority in fulfilling its function to reduce harmful interference to radio services. The authority prescribes CISPR standards in the official list of standards and implements them through the type approval process”.

Dr. Linoh Magagula, NMISA: “The massive proliferation of electromagnetic radiation emitting products causes a real issue with regards to EMC compliance in terms of interference. These products cover a wide spectrum of applications including medical, scientific, industrial, security and general consumer use. EMC non-compliance can have consequences, for example, interference with sensitive medical equipment and affecting readings of important measuring equipment. The scarcity of available bandwidth exacerbates this problem”.

Steve Alves, marketing director, Concilium Technologies: “From a measurement perspective, the reality of the increased adoption of many complex RF devices using low power transmission and complex modulation schemes would increase the need to ensure devices are compliant, even if the digital modulation schemes may prove to be more immune”.

Dr. Linoh Magagula, NMISA

Nico van Rensburg, president, South African Radio League: “As radio amateurs, we are very concerned about the problem. Due to the very nature of the radio amateur service with low power operations including the use of sensitive receivers, the increase in the RF noise floor has prompted us to hold a workshop and set up a workgroup to study the problem and provide ICASA with actionable information about non-compliant electronic products that cause radio frequency interference”.

In your experience, has interference as a result of non-EMC compliance caused system failure/s or degradation of a service?

Ruplal: “The current process seems to be working well and we have not had any major incidences of interference as a result of non-EMC compliance.”

Alves, Magagula, Ruplal and Van Rensburg: “Our emergency communication group’Hamnet’ has from time to time experienced interference during their communications support of sporting events. Some LED traffic lights are a major source of unwanted noise.”

The SABS develops the standards but cannot regulate standards which are the domain of ICASA. Type approval to some extent regulates that only compliant equipment may be sold including equipment that may cause unintentional RF interference. In your opinion, does ICASA do enough to ensure EMC compliance? What measures should be taken to improve the situation? Should ICASA be acting proactively and not just on complaints of interference?

Praneel Ruplal: “Given the resources at the disposal of the regulator, a reactive approach is currently the only approach that is viable. ICASA would ideally like to take a more proactive approach and conduct a “continuous compliance” campaign, whereby random samples of equipment is tested for type approval compliance. ICASA approaches EMC compliance both proactively and reactively. ICASA proactively ensures compliance through the type approval of electronic communication equipment before it enters the South African market, and reactively ensures compliance by attending to non-compliance complaints that are brought to its attention.”

Steve Alves, Concilium Technologies

Dr. Linoh Magagula: “With rapid advances in technology and exponential growth of new electronic products in the market coupled with easy importation of electronic gadgets for personal use, it is a challenge for ICASA to catch-up instantly with the changes. As such, they have to rely on complaints of interference rather than be proactive in ensuring EMC compliance. Of course, it is advisable that they try to be as proactive as much as they possibly can. I think in the main, ICASA must just be strict on type approval and ensure that the products are subject to declaration of conformity through random audits or other means, as well as introduce methods or systems to ensure that products satisfy essential protection requirements.”

How will be the emergence of IoT initiatives affect EMC? ICASA is currently reviewing its Type Approval regulations to simplify the process which should encourage more companies to submit their products for type approval.  Do you have any other suggestions to curb electromagnetic interference?

Praneel Ruplal: “ICASA believes that if the conformance framework is robust enough, there should not be any problems in terms of EMC. ICASA’s efforts to curb electromagnetic interference are informed by international best practice in the form of the ITU and CISPR. It should also be noted that the Type Approval regulations are not currently being reviewed. ICASA, however, has undertaken a public consultation process to determine the possibility of exempting certain equipment from type approval in terms of section 35(2) of the ECA. A discussion document was published on 28 September 2016 (Notice No 621, GG 40309) and a position paper was published on 31 March 2017 (Notice No 248, GG 40733) to that effect.”

Magagula: “Indeed, with the rapid advances in technology and the fact that many electronic products are emerging with the IoT initiatives, coupled with the scarcity of bandwidth, it is very likely that EMI will become more common. This will indeed require the manufacturers to design products that are immune to EMI. Unfortunately, there will always be a trade-off between quality and costs. However, if the manufacture of the products is standardised, the costs can be offset.”

Should manufacturers place more emphasis on designing equipment that has a higher immunity to electromagnetic interference? Are there cost-effective practices that should be considered?

Ruplal: “There are immunity standards that are applicable to electronic communications equipment. ICASA could possibly liaise with the industry to regulate immunity. It should be noted that the authority has recently entered into a Memorandum of Understanding (MoU), signed on 30 March 2016, with the SABS, which enable the two entities to collaborate in ensuring compliance of non-telecommunications equipment with EMC/EMI standard. The MoU facilitates a more robust process of issuing EMC/EMI Certificates of Compliance on the non-telecommunications products with a view to improve the EMC/EMI environment.”

Steve Alves: “The reference to manufacturers designing in higher immunity to radiation, I would think that the steps needed to reduce unintended radiation would be similar to those required to provide higher immunity against it. It would cover virtually all electronic research and development and manufacturing.”

Nico van Rensburg,SARL

Nico van Rensburg: “From time to time we receive complaints from the public that a radio amateur is interfering with a TV or sound system. When an investigation team investigates the complaint it is often found that the TVs or sound systems are sub-standard and not the radio amateur’s equipment or operation. Manufacturers can also do more to include detailed installation instructions. We recently investigated a case of interference caused by a geyser load controller. On investigation, it was found that the load controller was within EMC specification, but that incorrect installation was the cause of the problem. More detailed installation instruction could have prevented the interference.”

Thank you to the contributors to our EMC discussion. Poor compliance to meet electromagnetic compatibility standards will continue to dominate discussion in the engineering media and we invite you to be part of it. It is a complex subject that requires a better understanding of how radio spectrum noise is generated by many different types of devices. For instance, the subject of incidental radiators, devices that are not designed to generate or emit RF energy but do so as a result of their operation are not well understood and often overlooked. This category includes electric motors, light dimmers, switching power supplies, LED light and other power saving lights, utility transformers and power lines to list some. Noise from such sources is expected to be minimised with “Good Engineering Practices.”

Send comments to hansvandegroenendaal@ee.co.za

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