Could Your Product be Exempt from EMC Testing Altogether?

This week I’m going to talk about a few little known exemptions that I learned about when I was wading knee deep through the murky waters of several regulatory standards. I hope you can take advantage of a few of them and save yourself and your company some serious money. Firstly, I’ll focus on exemptions related to the EMC Directive for CE Mark testing. Then I’ll go into the top 10 exemptions to part 15 of the FCC’s rules! Please let me know your thoughts in the comments section at the bottom.

CE Mark Exemptions

CE Mark testing under the EMC Directive is usually quite a bit more expensive than FCC testing because it involves emissions and immunity testing whereas FCC testing usually only involves emissions testing. Therefore, if you can avoid it you stand to save some serious time and money.

The latest guide for the EMC Directive outlines many products that are exempt. Firstly, take a look at this flow chart that gives you a general overview of the applicability of the EMC Directive. CE_Exemptions If you’re reading this blog post, the chances are that you are involved with the design of some kind of electronic or electrical equipment, so it’s safe to skip the exemption at the top of the tree.

Next is the ‘excluded product families’ exemption. This refers to equipment covered by other standards such as radio equipment (covered by the R&TTE Directive instead). This doesn’t necessarily mean that EMC testing won’t be required for your product; it is usually just defined differently in another standard.

Components, sub-assemblies or other units which are intended for incorporation into apparatus, but which have no “direct function” for the end user, are not considered to be apparatus for the purposes of the EMC Directive. This is a good one to take advantage of if your company makes electrical products that will be integrated into other equipment. Note that your end customer may demand proof of compliance even if it isn’t mandatory.

Some examples of this are:

– Components forming parts of electrical circuits, e.g. resistors, capacitors, coils, transformers, diodes, transistors.

– Cards or modules required for the minimum level of function of the apparatus, e.g. central processing, minimum memory.

– Internal power supplies, including batteries- cathode ray tubes, light-emitting diodes (LED’s), liquid crystal displays (LCD’s).

– Private telecommunications and data networks

9 kHz Lower Limit

Measuring emissions from electrical equipment in Europe is only required for equipment that has internal switching above 9 kHz. This may be especially useful knowledge if you are designing a low frequency product such as a simple micro-controller or a low frequency switching power supply. If you have the flexibility to drop the highest clock frequency in your product below 9 kHz, then do so because you’ll avoid emissions testing altogether and save yourself a headache!

Low Voltage Directive (LVD) Exemptions

Closely related to the EMC Directive for CE Mark compliance is the LVD which covers electrical safety requirements. For many electronic/electrical products destined for sale in Europe, the recipe for demonstrating compliance with the rules is:

CE Mark  = EMC + Safety (The LVD)

And the LVD applies to: “all electrical equipment designed for use with a voltage rating of between 50 and 1000 V for alternating current and between 75 and 1500 V for direct current. Voltage ratings refer to the voltage of the electrical input or output, not to voltages that may appear inside the equipment.

I’m not particularly familiar with safety requirements, but there is a well known method that a company can use to avoid this arduous testing requirement. Typically safety testing costs $5000+ per product, plus an annual ‘maintenance’ fee. It’s obvious why companies seek to avoid the fees if possible and if safe to do so.

Based on the scope clause above, you can see that if you reduce the input voltage to your product below 50V AC or 75V DC, then the directive does not apply. If your design constraints allow, rather than having a mains AC input into your product, all you need to do to avoid the LVD is purchase a pre-approved (CE Marked) AC-DC power adapter and ship it with your product.

Make sure that you trust the power adapter vendor, because often cheap power supplies will bear the CE Mark, but not actually be compliant. This can bite you in the butt because a non-compliant power adapter can cause your whole product to fail a number of tests such as conducted emissions, surge and EFT. I’ve also witnessed cheap power adapters that were ‘cost reduced’ after initial passing samples were provided, which lead to a conducted emissions failure!

It’s key here to note that even if your device is exempt from the LVD, there may caveats or other safety standards that apply to your product. Always double check with a test lab, but also read between the lines of their ‘sales speak’ to work out what is mandatory and what are just scare tactics.

Top 10 FCC Exemptions

Most electronic devices destined for sale in the US fall under Part 15 (CFR 47) of the rules for limits to the unintentional (and sometimes intentional) emission of radiation. There are a number of exemptions that you may be able to take advantage of that you should keep in mind when designing your products. You can find the bulk of this info in section 15.103 of the rules. The FCC  recommends that you still aim to comply with the rules, and they have the power to halt sales of your device if the device has been found to cause harmful interference, so use with caution! FCC testing exemptions

1. A digital device utilized exclusively in any transportation vehicle including motor vehicles and aircraft. (Note: wireless devices are subject to other FCC rules)

2. A digital device used exclusively as an electronic control or power system utilized by a public utility or in an industrial plant. The term public utility includes equipment only to the extent that it is in a dedicated building or large room owned or leased by the utility and does not extend to equipment installed in a subscriber’s facility.

3. A digital device used exclusively as industrial, commercial, or medical test equipment.

4. A digital device utilized exclusively in an appliance, e.g., microwave oven, dishwasher, clothes dryer, air conditioner (central or window), etc.

5. Specialized medical digital devices (generally used at the direction of or under the supervision of a licensed health care practitioner) whether used in a patient’s home or a health care facility. Non-specialized medical devices, i.e., devices marketed through retail channels for use by the general public, are not exempted. This exemption also does not apply to digital devices used for record keeping or any purpose not directly connected with medical treatment. (Other EMC rules usually apply instead)

6. Digital devices that have a power consumption not exceeding 6 nW.

7. Joystick controllers or similar devices, such as a mouse, used with digital devices but which contain only non-digital circuitry or a simple circuit to convert the signal to the format required (e.g., an integrated circuit for analog to digital conversion) are viewed as passive add-on devices, not themselves directly subject to the technical standards or the equipment authorization requirements.

8. Digital devices in which both the highest frequency generated and the highest frequency used are less than 1.705 MHz and which do not operate from the AC power lines or contain provisions for operation while connected to the AC power lines. Digital devices that include, or make provision for the use of, battery eliminators, AC adaptors or battery chargers which permit operation while charging or that connect to the AC power lines indirectly, obtaining their power through another device which is connected to the AC power lines, do not fall under this exemption.

9. Same as the low frequency exemption for CE, if your device doesn’t generate and use timing signals or pulses at a rate in excess of 9,000 pulses (cycles) per second (9 kHz), then you can avoid emissions testing altogether.

10 Home-built devices: Equipment authorization is not required for devices that are not marketed, are not constructed from a kit, and are built in quantities of five or less for personal use. It is recognized that the individual builder of home-built equipment may not possess the means to perform the measurements for determining compliance with the regulations. In this case, the builder is expected to employ good engineering practices to meet the specified technical standards to the greatest extent practicable.

Caveat: Responsible parties should note that equipment containing more than one device are not exempt from the technical standards in this part unless all of the devices in the equipment meet the criteria for exemption. If only one of the included devices qualifies for exemption, the remainder of the equipment must comply with any applicable regulations. If a device performs more than one function and all of those functions do not meet the criteria for exemption, the device does not qualify for inclusion under the exemptions. (Note: for example, if you have a device with a wireless transmitter and some baseband circuitry that happens to be exempt, the wireless transmitter still has to be tested).

Wrap Up

So that was an outline of a few exemptions that I hope you can take advantage of at some point in your career. Please confirm with your test lab whether you are indeed exempt as there are some caveats to this information. If you can’t take advantage of any exemptions, you may want to have a look at how to source test equipment bargains for doing some pre-compliance testing.

Have you ever successfully used exemptions? What has your experience been with your test lab giving you guidance on what tests you can avoid? Or any other comments/suggestions in the comments section below! In a future post I’ll delve into some lesser known ways to avoid testing, such as risk assessments (for CE), in-house testing substitutions and ways to minimize re-testing of products in a family with minor hardware differences.

19 Comments

  • Steve Boegle

    Reply Reply May 6, 2014

    I believe that power supplies that produce signifigant energy levels are covered by IEC safety standards ( and the LVD ) regardless of the voltage produced. These standard not only address voltage levels, but also heat rise and fire safety. High currents can cause fires regardless of voltage. Its not a ggod iea to assume your are excempt form safety standards because of low operating voltages only. There are also product specific safety specs that address low voltage power sources like DC/DC converters.

    • Andy Eadie

      Reply Reply May 6, 2014

      Hi Steve, thanks for the input. I couldn’t find any reference in the ‘Guidelines on the application of the the LVD” (http://ec.europa.eu/enterprise/sectors/electrical/files/lvdgen_en.pdf) that includes higher power equipment not otherwise excluded by the scope mentioned in the article. Could it be that the equipment you have in mind is subject to safety standards other than the LVD?

      I absolutely agree that you should verify the applicability of other safety and EMC standards to your product. This article only outlines some potential exemptions to the specific standards mentioned. when in doubt, ask your test lab!

  • Ted Warren

    Reply Reply September 17, 2014

    Hi Andy
    I work for a UKAS accredited UK test lab. Our interpretation of the LVD is that if you supply a product that is powered from the mains, the whole product is within the scope of the LVD, irrespective of whether it consists of a separate power adaptor or not. Having a separate adaptor that is already certified simplifies the testing and reduces the cost, but does not remove the requirement for fully assessing the product.
    Steve Boegle is correct that Safety requirements still apply for equipment below the LVD limits, but this is not invoked by the LVD. For consumer equipment the GPSD would apply, or for radio equipment the R&TTE Directive applies. Neither of these have lower voltage limits. Often the same Standards as listed for the LVD can be used to confirm compliance of excluded equipment.

  • Sam

    Reply Reply January 14, 2015

    Can you clarify the exemption statement 3:

    A digital device used exclusively as industrial, commercial, or medical test equipment.

    I ask, as one can interpret this as meaning:

    a. industrial, commercial, or medical test…. equipment
    meaning – Industrial equipment, commercial equipment, or medical test equipment

    b. industrial, commercial, or medical …test equipment
    meaning – Industrial test equipment, commercial test equipment, or medical test equipment

    Which is it, as there is some ambiguity with the statement.

    Thank you in advance!

    • Andy

      Reply Reply January 22, 2015

      Yeah, I agree there’s some ambiguity there. You could look at the ‘definitions’ section in part 15 of the rules. If that doesn’t turn up anything, then you’d need to file a question with the OET at the FCC here: https://apps.fcc.gov/oetcf/kdb/forms/InquiryForm.cfm

    • Ramon Torres

      Reply Reply November 15, 2016

      The meaning of this sentence is your item b

      Industrial test equipment, commercial test equipment, or medical test equipment.

      “Test” equipment is the key word. Otherwise, the definition of Class A would make no sense.

  • N. Gladstone

    Reply Reply January 16, 2015

    Are there any exemptions for “small run” items (powered off of mains)? It seems that there isn’t a proper exemption for someone who say, designed a unique device for a small market but never expects to profit more than $5k off of building a small run of devices (say 100 or so). Where do the small time guys fit in this picture?

    • Sam

      Reply Reply January 17, 2015

      Good day N. Gladstone,

      I believe the standard allows for a limited number of prototypes only…5 if I remember… and I believe that they cannot be sold and must be suitably labelled… i.e. for testing only.
      To my knowledge there is not exclusion for small firms and/or limited production runs. In reality small volumes would be off their radar and would only be officially an issue if the device caused excessive interference resulting in complaints. However, if one exports the items then most countries require some form of conformity declaration which could get you in hot water should you fraudulently completed it.

      • John

        Reply Reply April 26, 2015

        Are you sure that the ‘testing exemption’ applies to even transmitters?

  • David

    Reply Reply March 12, 2015

    Can you comment on host devices containing an MCU, storage devices such as a SSD, ethernet switching, etc. that support otherwise certified RF modules (ISM, wifi and cellular)? It is my understanding that such devices REQUIRE registered testing lab certification, but I have a client that is under the impression that those host devices can be self-certified.

    • Andy Eadie

      Reply Reply March 13, 2015

      Depends where you’re selling into. The US, Canada, Australia, Japan etc would all require testing at a listed or accredited test lab. Europe is a little more ambiguous, but a long story short, yes you would also need to have it tested at a 3rd party lab. If you were trying to do it yourself legally, somehow you would need to prove compliance with the rules, so you would essentially need to have a full lab yourself.

      • David

        Reply Reply March 19, 2015

        Andy,

        Thanks for the reply. My client now understands the necessity of full testing and is proceeding forthwith. They were unaware of the issue (their expertise lies elsewhere) and expressed their appreciation for my bringing it to their attention.

        Your response confirms my viewpoint on this important matter. The costs associated with the launch and shipping of a non-compliant product would have been staggering.

        Again, thanks!

  • John

    Reply Reply August 7, 2015

    hi,
    Does medical montior device which is battery powered (DC battery of 3V) requires to go through EMC testing?

  • Ryan

    Reply Reply August 18, 2015

    “10 Home-built devices: Equipment authorization is not required for devices that are not marketed, are not constructed from a kit, and are built in quantities of five or less for personal use.”

    So kits would still need FCC certification?

  • Kumar

    Reply Reply January 21, 2016

    So, a 6V/9V/12V battery operated device would not need certification? The batteries will not be charged while inside the device, nor will it be AC powered – no power adapter. There will be no Bluetooth or other wireless control.

    Thanks.

  • Barb

    Reply Reply May 24, 2016

    If a component, such as a network card, is going to be installed in a system, is it exempt from FCC?

  • Nitesh

    Reply Reply December 3, 2016

    I want to understand about conducted immunity test exemption.
    Is it possible exempt conducted immunity test if my device is battery operated industrial measurement device with USB micro AB connector port used for charging and same port is used for PC/Laptop Communication?
    I want to go for CE certification. I am using CE certified USB power adapter charging and All function of device works only with USB commands through laptop, and device never uses AC power for its functionality.
    Please help me.

  • Bruck

    Reply Reply February 10, 2017

    Is my understanding correct that a heating appliance that has a random phase control switching at only 120Hz and drawing 16Amps is exempt?

  • Lindsay Smith

    Reply Reply March 3, 2017

    Regarding the FCC exemptions (specifically #10): What about if I were to have “home built” devices that I will not be selling or marketing in any way, but will be given away to research partners for Beta testing the device? This would be a quantity greater than 5 devices.

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