Info and News

As we go to press:  New EMC Directive Published

The long-awaited revision of the European Union’s EMC Directive has arrived—just as we are going to press.  Directive 2004/108/EC (dated Dec. 15, 2004, published in the Official Journal of the European Communities on Dec. 31) rewrites and repeals the old EMC Directive (89/336/EEC, with amendments).  We’ll note a few high points, and provide more detail in the near future.  The text of the Directive may be found at:

http://europa.eu.int/eur-lex/lex/LexUriServ/site/en/oj/2004/l_390/l_39020041231en00240037.pdf

For many manufacturers, the new Directive will provide clarification but will not bring about a significant change.  For most equipment, compliance will be demonstrated by application of harmonized standards published in the Official Journal, and CE marking will continue as before and the generation of a declaration of conformity, although reference will now be made to 2004/108/EC rather than 89/336/EEC and some additional details must be provided.  Some observations:

• This Directive repeals 89/336/EEC on July 20, 2007.
• The transitional provisions state that equipment complying with the provisions of the original EMC Directive, 89/336/EEC, and placed on the market before July 20, 2009 is considered compliant.
• The demonstration of non-compliant equipment at trade fairs or other exhibitions is specifically authorized, so long as the equipment is accompanied by a visible statement that it is non-compliant and not to be placed on the market until it is made compliant.  Further, precautions must be taken to avoid causing electromagnetic disturbances.  This is a welcome clarification.
• The definition of apparatus has been refined.  Basically, it is a finished product provided to an end user that is liable to generate or be affected by electromagnetic disturbance.  This can include sub-assemblies intended for end-user installation.
• Technical documentation supporting compliance is required and must be retained for ten years after the last date of manufacture.
• The definition and rules applicable to installations are clearer.  An installation is a combination of apparatus intended for use at a particular location.  The key issue for an installation is not CE marking or specific standards-related performance; rather, it is compliance with the essential requirements of non-interference and immunity using good engineering practice.  Documentation as to how the requirements have been met --engineering analyses or test results—have to be kept created and maintained.
• The role of the “technical construction file,” or TCF, has changed.  In the original Directive, “competent bodies” were to be consulted and to review a TCF in the event a product was not covered by harmonized standards.  Under the new Directive, this is no longer the case.  The new Directive renames these bodies “notified bodies,” and their use is purely voluntary.  If a manufacturer wishes to have his compliance documentation reviewed by a notified body, he is free to do so, but it is not necessary; further, there is no compulsory use of the notified bodies when the existing harmonized standards do not fully cover a particular piece of equipment.

As we mentioned, we’re going to press now, but we’ll provide more details soon.

FCC Releases Broadband Study on US Internet Access

The FCC has released a survey on the penetration of broadband Internet Access, based on data it collects from ISPs (Internet Service Providers).  As of June 30, 2005, there were 32.5 million high-speed lines connecting homes and businesses to the Internet—a 15% increase over the previous six months, and a 38% increase year-over-year.  The year-over-year increase for residential and small business users was even more dramatic—an increase of 46%.  The chart below shows the dramatic growth in U. S. high speed access over the past five years.

Some interesting facts from the FCC’s report:

• The FCC classifies all lines delivering 200 kbps or greater data rates in at least one direction as “high-speed lines,” and further categorizes as “advanced services lines” those providing data rates in excess of 200 kbps in both directions.  Approximately two thirds of the high-speed lines—some 23.5 million—provided advanced services connection.
• High speed coaxial cable modems have the lion’s share of the U. S. internet market, with 18.6 million installed lines.  ADSL (asymmetric digital subscriber line) runs a strong second, with 11.4 million lines.  The remaining 2.5 million high speed connections are accounted for by a number of different satellite, fiber, and wireless technologies.  Both cable modem and ADSL line counts grew rapidly over the past year—coaxial connections were up by 36%, and high speed ADSL was up by 49%.

The FCC’s report contains a lot of interesting information, including state-by-state breakdowns of line density along with population and income demographics.  The full report is available from the FCC at:

http://www.fcc.gov/Bureaus/Common_Carrier/Reports/FCC-State_Link/IAD/hspd1204.pdf

NEBS:  Verizon Provides New Guidance on Acoustic Testing

Verizon has given additional guidance on acceptable acoustic noise performance for equipment undergoing NEBS certification testing.  Telecommunication equipment installed in Verizon’s central offices must generate no more than 65dBA sound pressure when tested at temperatures between 20^o and 30^oC.  The test laboratories performing the assessment are to record the sound pressure level with the unit operating normally.  In addition, the test labs shall also test the unit’s sound pressure level when the fans are operating at their maximum speed, if there is a variable speed.  However, the pass/fail criteria applies to the sound pressure recorded at the normal temperature range of 20 to 30 degrees, not at the maximum fan speed.

Presumably, the reason for this is that maximum fan speed will only occur if the central office housing the equipment overheats.  Under this exceptional and temporary fault condition, cooling the equipment to protect it and keep it operating becomes more important than the long-term need for controlling noise under normal operating conditions.

Telecordia Plans GR-63 Overhaul

Telecordia is the maintainer of the NEBS (Network Equipment Building Systems) Standards, which provide the basis for many of the construction and performance requirements the telephone operating companies impose on equipment manufacturers.  Two of the more prominent members of the NEBS GR-CORE (General Requirements) family are GR-1089, which addresses electromagnetic compatibility, and GR-63, which is concerned with environmental issues such as corrosion, dust resistance, earthquake performance, acoustics, and fire spread performance.  Telcordia has recently announced its intention to develop a new edition of GR-63, which would be Issue 3.  Industry participants are invited to participate in the development of this and other Telcordia standards, for a fee.

Although the scope of issues to be addressed may change, the current areas of concern include:

• Revision of the Fire Spread Criteria and Test Method:  The current issue of GR-63 equipment assembly fire spread criteria and test methods are based on a draft version of ANSI T1.319 dating back to 1996.  Since that time, T1.319 was completed and released in 2002, and changed somewhat in the process.  In addition, some companies have imposed their own requirements that are in addition to both the existing GR-63 requirements and those of ANSI T1.319.  Issue 3 will attempt to incorporate the developments in fire testing that have occurred in recent years so that customer test requirements could again be satisfied with a single test method.
• Revision of the Acoustic Noise Criteria and Test Method:  At present, the acoustic noise requirement for network equipment is based on sound pressure.  Sound pressure is measured at a single fixed point.  A more comprehensive way of measuring acoustic noise is “sound power.”  In a sound power measurement, sound pressure is measured at a number of points over a surface surrounding the equipment.  The pressure measurements are summed to provide an estimate of the total sound power produced by the equipment under test.  Telcordia notes that recent industry practice is moving toward the sound power approach and it may be appropriate to introduce it into GR-63.
• Operating Temperature and Humidity Criteria:  The operating temperature and humidity test is currently based on 1996 drafts of ANSI T1.304 and ETSI 300 019-2-3.  It would be desirable to update GR-63’s test method to demonstrate conformance so that one test could demonstrate conformance to NEBS, ANSI, and ETSI criteria.
• Vibration and Shock Resistance:  Issue 2 includes operational and packaged vibration tests which are based on a swept-frequency sine wave.  Current thinking is that a random vibration test provides a better simulation of the real-world vibration threat.  In addition, an operating shock test (not currently in the standard) may also be added, because transients exist with a frequency content outside (i.e., above) the range contained in the earthquake tests currently performed.

Look for this effort to go on through much of 2005.  We’ll announce progress and results as we hear of them.

Telcordia Announces Plans to Develop New Edition of GR-1089

Telcordia has also announced its intention to update GR-1089, the NEBS standard concerned with Electromagnetic Compatibility and Electrical Safety.  This project would result in a new edition, reissued as Issue 4.  A number of the proposed changes involve OSP (outside plant) equipment and environments; others will affect all equipment.  Telcordia’s announced menu of issues, which may change depending on input from industry participants includes:

• New Equipment Port Type:  This would add remote site telecommunications lines as a port type.  This means that surge testing requirements may be different, and probably more severe, for equipment located outside of the CO (central office) environment.
• Protection Coordination:  This would involve more detailed co-ordination between the protection provided by primary protectors and the secondary protection contained within the equipment.
• Test Conditions for Multi-wire Interfaces:  Some equipment contains multi-wire interfaces in addition to the more common 2 and 4 wire connections.  Telcordia is proposing to introduce test conditions for these.
• Long-term Power Fault Induction Testing:  There may be a re-evaluation of the second level fault current test.  Also, the current levels of long-term power fault inductions will be investigated and a new test in this area may be proposed.
• Surge Testing of Power Ports under Normal Operation:  Presently, GR-1089 does not require that telecommunications ports be in normal operation during first-level lightning and AC power fault testing.  It is possible that test requirements and procedures for surging ports while powered may be introduced.
• Surge Criteria for DC Power Ports:  GR-1089 does not presently contain surge criteria on the DC power interface of equipment fed locally.  However, recent field studies have suggested that failures can occur from surges on the local DC power port—the –48V “battery” supply.  The new issue may introduce new criteria for surge performance on this port.
• Environmental Cycling with Surges:  At present, telecom line surges, including first-level, and AC power fault tests are performed at room temperature.  There is concern that this might be insufficient to simulate operational temperatures and humidities seen in outside plant applications.  Telcordia is contemplating a combined environmental and surge requirement for equipment located in harsh environments.
• Power Limitation Criteria for Remotely Powered Equipment:    OSP equipment that draws power from CO facilities may have power limitation and performance requirements imposed.
• Updating Conducted Emissions and Immunity Requirements for Broadband Lines:  There have been recent changes in industry practice in this area that will be discussed and may introduce modifications to the existing requirements.

Info and News brought to you by Curtis-Straus LLC 527 Great Road Littleton MA 01460
Phone 978.486.8880 Fax 978.486.8828

To see all previous news letters click here

To unsubscribe to this email click here