New Legislative Framework
By J. M. Woodgate B.Sc.(Eng.) C.Eng. MIET MIEEE FAES
New Legislative Framework
The Department of Business, Innovation and Skills circulated a notice in April, part of which reads:
As you will probably be aware, eight EU New Legislative Framework (NLF) alignment Directives have now been published in the Official Journal. The NLF implements the text of EU Decision 768/2008/EC and makes reference to Regulation 765/2008/EC. Together this creates a more coherent legislative framework for the marketing of products in the EU Internal Market; providing improved traceability and clearer requirements on economic operators, greater accountability in the designation and consistency of performance between notified bodies, and the alignment of conformity procedures and commonly used definitions within the conformity assessment process. The NLF does not revise sector-specific elements of existing Directives; no changes have been made to the scope or essential requirements.
The Directives aligned are:
• Explosives for Civil Uses
• Simple Pressure Vessels (SPV)
• Electromagnetic Compatibility (EMC)
• Non-Automatic Weighing Instruments (NAWI)
• Measuring Instruments (MID)
• Lifts and Safety Components for Lifts
• Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres (ATEX)
• Electrical Equipment Designed for Use within Certain Voltage Limits (LVD)
Member States have two years to transpose these Directives. In the UK we plan to undertake this work as a package to minimise the burden on all those involved. I will contact you again soon to provide further details of how we will take this forward, which will of course include an appropriate formal consultation on implementation of the aligned Directives.
Maintenance of IEC 61000-4- series Basic standards
Most of these standards are the responsibility of MT12 of IEC SC77B, but some are 'owned' by the other sub-committees of TC77. MT12 is extremely active; the members produce a large number of document for discussion at meetings.
MT12 met in February 2014, with the following results.
A very long list of potential improvements was discussed; some 16 topics were mentioned.
A shorter list of five items was discussed for this standard, including improved calibration procedures and the future of the test at 5 kHz.
This was at the FDIS stage, so certain items could not be progressed until the next maintenance cycle, which has already started. A request for an Interpretation Sheet could not be accepted because the subject does not concern IEC 61000-4-5 but one or more product standards. But informative text may be added in the maintenance process. A request to exempt some products from testing at all levels of the disturbance was not accepted. The committee reiterated that all-level testing is always required. This may cause considerable design problems for some products.
This standard hasn't been changed since 2001, and it is now under extensive revision. A number of topics are being studied, and some reported results are inconsistent, or appear so. A CD was circulated in February 2014.
A number of very significant improvements are required. A CD is being drafted.
The MT will continue to hold two meetings a year.
WG6 is revising this standard and a CD is forecast for December 2014. Questions have been raised about the very fast rise and fall times required of the test generator, as they can affect cost considerably. The purpose of these specifications may be to restrict the inductance of the test source: The maximum rise or fall time (1% to 90% amplitude) is 5 µs and the non-inductive test load is 100 ohms. Using the rule that the rise time is 2.2 times the time-constant L/R, the maximum permissible source inductance is 220 µH. A finite inductance is usually required for stability if the source is an amplifier. But the inductance of the IEC TR 60725 reference supply impedance for 230 V 50 Hz is 796 µH. The test generator has to simulate higher-current supplies with less inductance but few EUTs are non-inductive loads.
A DC was circulated about the maintenance of this standard. A number of National Committees expressed support for an early revision, but some proposals were rejected by the Secretariat. Discussions could become interesting.
IEC TR 61000-4-38 Calibration and verification protocol for flicker compliance test systems
This is a new TR, produced by WG2. It should help to reduce the possibility of different test houses returning different results on the same EUT.
IEC 61000-4-36 (IEMI [Intentional EMI] immunity test methods)
This document has reached the CDV stage. It is quite long - 79 pages. Let us hope that its provisions seldom need to be verified as effective in practice.
Fragment 2 of Amendment 2 , on the use of an external preamplifier with a measuring receiver, has reached the first voting (CDV) stage. The advice is not to do it unless absolutely necessary and then to be very careful to avoid overloading the receiver.
CISPR/A WG2 has produced a DC (Document for Comment) on EUT size specifications in CISPR publications. These have traditionally been developed on the basis of the dimensions and characteristics of the test fixtures, so differ between standards. The discussion and proposed solutions extend to 11 pages, which si long for a DC. It includes a proposed Informative Annex to explain the background in terms of four criteria for EUT size. The smallest size resulting from considering these criteria is definitive. The criteria are:
limiting field-strength conversion effects between short-distance measurements and those at the distance specified in the standard;
limitation of near-field effects;
limitation of effects due to antenna directivity;
limitation of effects of EUT coupling to absorbing material.
Task Force (TF) on wireless power transfer
A DC was circulated on this subject and the report has been circulated. 12 experts have been appointed to the TF, which will meet for two days in June 2014. The TF will develop requirements to be added to CISPR 11 and may provide advice to other committees studying WPT.
Who knows? The number of meetings, especially BSI meetings, still tends to reduce, as work-loads increase and budgets decrease. But the brighter economic signs may reverse this trend at some future date.