Written by Steve O’Steen on July 8, 2016. Posted in Information Technology
There is a new EMC emissions standard that has been published and will replace standards we have been working with for decades. EN55032 for multimedia equipment has been published in the European Union Official Journal and is now accepted as a route for compliance. It will replace EN55022 Information Technology Equipment, EN55013 Sound and Television Broadcast Receivers and Associated Equipment, and EN55103, a product family standard for Audio, Video and Entertainment Lighting Equipment for Professional Use.
During the interim period we are now in, either standard, old or new, may be applied. But on March 5th, 2017 the old standards will be withdrawn and the new EN55032 will be the only route to compliance. But don’t sit back and wait until 2017! The important point to understand is that if you are shipping product to Europe today, and you expect to still be shipping that product in 2017, it would be wise to be applying EN55032 to new products now. A plan should be made as well to bring legacy products into compliance between now and March 5th, as there is no grandfathering.
Currently the European Union (EU) market is the only one harmonized to EN55032. And in some cases, the test methods and setup requirements between standards are not compatible and will require otherwise seemingly redundant testing. Therefore if you are shipping products to multiple markets it is likely that you will need to evaluate your product to more standards than you are accustomed to. For example, if you are selling to the USA, the EU and a third market that doesn’t yet recognize EN55032 (CISPR32), but still recognizes EN55022 (CISPR22), then you will need to test to ANSI C63.4 (FCC requirements), EN55032 and EN55022 (CISPR22).
There are some significant differences between EN55032 and the older standards it is replacing. Therefore, if you do test to EN55032 now, your emissions testing will still be valid after the 3/5/17 date. But if you wait, and continue using EN55022, 55013 or 55103 you are possibly going to require additional testing, experience loss of efficiencies and certainly have some last-minute headaches to stay compliant after March 5th, 2017. Here we will briefly discuss the differences in the standards and how best to avoid those headaches.
Products Affected: Information Technology Equipment (ITE) or Multimedia Equipment (MME) previously tested within the scope of EN55013, EN55022 or EN55103-1, that ships into the European Union after March 5th, 2017 is now within the scope of EN55032 and must meet the new requirements. EMC standards for MME and ITE equipment have now merged into the single EN55032 standard.
Changed Testing Requirements: The requirements of EN55032 will demand more focus on interface ports, port type and cable options including possible length of the cables and the type of signals on each port.
Aside from the power disturbance measurement which is no longer permitted, limit values and measurement procedures remain largely unchanged. A welcome change is that previously necessary multiple measurements for multifunctional devices will no longer be mandated. However, EN55032 does require testing on at least one of each type of port per function. As an example, if an EUT has two BNC ports, one is an input and the other is an output, both ports are candidates for Conducted Emissions testing. One bit of clarity the authors of EN55032 decided to add regarding the applicability of the I/O port Conducted Emissions test that EN55022 did not have, was to limit the testing to ports that can have cables >3m in length. This is the primary reason for the need of additional detail regarding the interface ports of the EUT and the cables that are used, offered, and/or recommended. Before testing, the EMC test lab will need port details like whether the port lines are balanced/unbalanced, number of lines or pairs, screened or unscreened. Each of the mentioned variables regarding the port type and expected cable construction can have a dramatic impact on the test method and expected test time. A full understanding of the EUT, primary function, ports, display type, typical display content, display resolution capability and EUT environmental parameters will assist in building an accurate test plan for the test laboratory.
Provided here is a thorough list of details and differences between the EN55032 standard and the standards which it replaces. Included are clarifications of previous ambiguities in the form of definitions and interpretations.
Multimedia Equipment (MME) includes ITE, audio equipment, video equipment, broadcast receiver equipment and entertainment lighting control equipment.
The environment of the EUT must be considered before testing.
The definition of a “Telecom Port” is absent in EN55032, replaced by “Wired network port.”
If a port satisfies the definition of more than one port type, it shall meet the requirements for each port type.
Unlike some other product specific standards, when considering what the highest frequency generated or used in an EUT, even the frequencies generated internal to an IC must be considered.
For Ethernet interfaces, the port must be forced to the highest data rate possible.
If the manufacturer specifies a port that can accommodate shielded and unshielded cables then both cable types need to be evaluated with that port.
The Class A warning to the end user must be included in the EUT manual.
An EUT is considered AC mains powered if it is intended to be powered via a dedicated AC/DC power converter. This is consistent with what is found in the current version of EN 301 489-1.
An EUT intended to be powered via a dedicated AC/DC converter shallbe tested with a representative power converter. If the manufacturer provides a converter, that converter shall be used for the testing. This requirement applies to Radiated Emissions as well as conducted emissions.
An EUT with a DC power port is only considered DC powered if it is not intended to get the DC power from a dedicated power inverter or POE. POE ports are considered wired network ports.
Each EUT mode of operation must be investigated while the ports are exercised.
Conducted Emissions testing is applicable to AC mains ports, Wired Network Ports and Broadcast Tuner Receiver ports, broadcast receiver tuner ports with an accessible connector, and RF modulator output ports.
Conducted Emissions testing on all but the AC port, broadcast receiver tuner ports with accessible connectors and RF modulator output ports is limited to ports that can have cables exceeding 3 meters only.
The host, whether the EUT or not, will be in the measurement area.
If the highest frequency generated or used by the EUT is unknown, the test lab will test to 6 GHz.
The EMC test report must contain clearidentification of each port tested.
The EMC test report must contain a description of how limits are calculated if the measurement distance is different than what is called out in the standard.
It is acceptable to mitigate emissions from accessory equipment as long as the mitigation means does not affect the emission levels from the EUT.
Unlike previous standards all of the emission limits and test methods are contained in the annexes.
Unlike previous standards, the current version of EN55032 will allow final radiated emission measurements to be made in a fully anechoic environment with a fixed antenna height.
Unlike previous standards, the current version of EN55032 provides Radiated Emission limits for Class A and Class B, below 1GHz at 3 meters and 10 meters test distance. The difference between the 3 m and 10m limits are a fixed 10dB.
Table A.6 includes emission requirements for FM Receivers local oscillator fundamental frequency and harmonics. All other emissions from the FM receiver must comply with the emission limits of Table A.4.
Unless the manufacturer specifies a more appropriate audio source, the EUT audio port (if equipped) should be exercised via a 1 kHz tone.
An EUT with a display or video port must follow the guidance found in Table B.1, with the most complex displays or video ports exercised via an ITU color bar and moving element. This is not allowed per ANSI C63.4 so, if the investigation includes FCC and EU, the test lab will require an additional Radiated Emissions scan and an additional conducted emissions scan. The moving element on the display is ideal for monitoring the susceptibility during the immunity suite of tests.
For the wired network ports, such as LAN, all but 10Base-T can be set to the maximum data rate for the port. For 10Base-T ports, compressed files should be transferred to create a LAN utilization in excess of 10% and sustain that level for at least 250mS.
The minimum test distance for 1GHz and below is 3 meters and for above 1GHz is 1 meter.
During Radiated Emissions measurements, any I/O line leaving the measurement area to connect with a remote AE should drop to the floor of the chamber but isolated by up to 150mm from the GRP before exiting through the appropriate chamber opening.
When making Conducted Emissions measurements on an EUT that has a dedicated ground connection, the ground needs to be connected to the reference point on the AMN and run parallel to the power cable, spaced no more than 10cm from the power cable.
Conducted Emissions measurements for tabletop equipment can be performed on a 80cm table or 40cm table.
Consider each of these items in an effort to reduce project and testing delays. To prepare for a successful project, know that the EMC test lab will need as much information about the EUT as early as possible in the project cycle with a special focus on the display capabilities and I/O port mix.
A full review of the EN55032 standard before testing and a review of the bullet points above will assist in your understanding of the changing requirements. The mandatory adherence to the standard will be upon us in less than nine months. If your product will still be marketed into the EU a year from now, then testing to the old standards now, will mean potential retesting again in March of 2017. Yet testing to the new standard now bypasses repeating the testing to the new standard again next year.
It should also be noted that in addition to the evolution of emissions to new standards, immunity test standards are changing as well. It will likely be a couple of years beyond the adoption of EN55032 emissions that we see the new EN55035 immunity test standard become mandatory. Just know now that it is coming, it will change the immunity test methods in much the same way as emissions standards are changing today. Be prepared and proactive to avoid being a victim of these evolving standards.