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July 2016
Terry K. McGowan, FIES, LC
ALA Director of 
Engineering  & Technology
Sponsored by:
Electromagnetic Interference and
LED Lighting Revisited


This is an update on the subject of electromagnetic interference (EMI) from LED lighting products and is intended to alert ALA manufacturers and retailers to ongoing regulatory developments in both the United States and Canada since my original Technology Newsletter on this topic in April 2015.

EMI Problems from LEDs
Are there EMI problems from LED residential lighting? For the most part, no. Although a better answer might be, not yet.

Right now, there are just a few residential lighting EMI problems being reported. But, the LED penetration in homes is currently estimated at only 5 to 10 percent of potential sockets, and it is growing rapidly. The EMI regulators, the United States Federal Communications Commission (FCC) and Industry Canada, think the situation will change as more than 5 billion sockets are filled with new LED bulbs and millions of LED fixtures are installed, each acting as a tiny radio transmitter, adding its EMI signal to the home environment. 

The Source of EMI from LEDs
Inside every LED bulb or fixture with an electronic driver, operating on the usual 120-volt residential AC electrical supply, are electronic circuits that generate high-frequency signals as they regulate power to the LED chip. According to the FCC, that makes such lighting products "unintentional radiators," or devices that generate radio frequency emissions as a byproduct of their normal operation. Such emissions must be limited, or they will interfere with the operation of other electronic devices in the home. The emissions may be transmitted through the air (radiated emissions) or they may travel on the power or control lines into the home wiring (line-conducted emissions). In either case they are subject to FCC limits, and so LED products must be tested.

LED Product EMI Testing and Labeling
Recently, the FCC clarified that testing of LED lighting products must cover the frequency range from 30 to 1,000 megahertz (MHz). Although LED circuits typically operate well below those frequencies, the FCC found that LED drivers can operate at higher frequencies non-periodically and generate what the FCC calls broadband emissions.  
FCC Declaration of Conformity label
That part of the radio frequency spectrum is a crowded, busy place, and includes FM radio, television, mobile phones, Bluetooth, GPS, and amateur radio, among other communication services. Tested and approved LED lighting products are marked with the FCC Declaration of Conformity label. 

Product EMI testing is typically done at the same time and by the same testing laboratories that also do the usual lighting product safety and performance testing. Manufacturers should check for markings on sourced components. Retailers should check for markings on fixtures and LED bulbs, including the specification sheets. There are unmarked and untested bulbs and components being sold. Right now, the United States and Canadian regulations are fairly well harmonized. However, Canada is considering adopting new standards that require EMI testing on a fixture basis, rather than a component basis, and the FCC is considering rules that would make LED lighting a new class of regulated products. Therefore, EMI regulations are likely to change over the next couple of years. 

On your behalf, the ALA has submitted comments to both Industry Canada and the FCC on these matters and has developed a formal position, which is included in the ALA 2016 Government Affairs Policy Book (Page 7). One of ALA's comments to the FCC was a recommendation to use standard industry definitions for LED products and components. I am pleased to report the FCC agreed to use the definitions appearing in the recently published Energy Star Lamps and Energy Star Luminaires and ANSI/IES RP-16-10 Nomenclature and Definitions for Illuminating Engineering (also available through the IES Bookstore). 

An FCC bulletin issued June 17, 2016, titled Radio Frequency LED Lighting Products, has more details. 

As always, your comments and questions on this subject are welcome.


Terry McGowan, FIES, LC
Director of Engineering & Technology