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CISPR annual meetings

By J. M. Woodgate B.Sc.(Eng.) C.Eng.  MIET SMIEEE FAES Hon FInstSCE MIOA

CISPR annual meetings

CISPR and its sub-committees had their annual Plenary meetings in Busan in South Korea in October 2018, so let's see what delights they have in store for us.

CISPR

  • CISPR TR 16-4-4 is to be updated and then considered for transformation from a TR to an IS (International Standard);
  • A decision on whether to start work on emission measurements up to 40 GHz is deferred to the next  Plenary. Meanwhile, National Committees (NCs) will be asked for comments;
  • More information is to be documented about special EMC issues in robotics that could not be covered by existing sub-committees. No new sub-committee will be formed now;
  • The Steering Committee is asked to study what needs to be done about 'radio enabled products', probably beginning with a clear definition;
  • A request to freeze radiated emission limits below 30 MHz at present levels was not accepted;
  • ITU-R will be informed automatically about changes in CISPR standards. Liaison at SC level will be permitted;
  • One NC will prepare a paper on testing lighting products during warm-up;
  • An EU challenge to the wording of the CISPR immunity criteria (A, B, C and sometimes D) will not be studied until CENELEC and ETSI have considered the matter.

This last one is a doozy! In trying to effectively convert standards into legal documents, in apparent defiance of EU policy, the Commission wants all references to manufacturer-determined specifications to be eliminated. This includes the wording:

No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the apparatus is used as intended.

The implication is that the degradation must be specified in the standards, as a 'one-size fits all' requirement, applicable to the lowest-cost consumer product and the most costly professional product, or even high-end hi-fi product. Fixed degradation can also penalize products which perform better than the manufacturer's specified performance. For example, if the spec says 'Signal-to-noise ratio 50 dB' and the fixed degradation is 3 dB with EMI present, a product that has a signal-to noise ratio of 56 dB must be rejected if the ratio falls to 52 dB with EMI present, even though this is better than the specification without EMI.

CISPR A (Test instruments and methods)

Amendment 2 of CISPR 16-4-2  ran into problems. The FDIS was approved, but subsequently errors were found and an agreed improvement was not implemented. This was put down to problems with the merging of approved fragments. A Corrigendum can fix the errors, but the improvement has to wait for the next maintenance cycle.

An ad hoc group from CISPR A and  CISPR I is studying the correct way to terminate power cables at the supply end when doing radiated emission measurements. The present test method has reproducibility problems because the terminating impedance is not defined. GB experts have pointed out that a proposed fully-balanced termination is not realistic if the EUT produces both differential- (DM) and common-mode (CM) conducted emissions, because in real life the supply is unbalanced and that causes mode conversion from non-radiating DM to radiating CM. A round-robin test of a partially-unbalanced terminator is being organized.

Future work items are:

  • Revision of CISPR 16-4-2;
  • Maintenance of CISPR 16-2-1, 16-2-3 and -3 to take in material from CISPR 32;

CISPR A is not receiving documents about shared work from CISPR D and SC77B, and requests resolution. CISPR A has 33 active projects at present, many of which will be combined into circulated documents.

CISPR B (ISM equipment)

CISPR B has 7 current projects,

  • radiated emissions associated with WPT, 9 kHz to 30 MHz;
  • requirements for emissions at DC power ports for equipment other than solar PV inverters;
  • introduce the amplitude probability distribution (APD) method for Group 2 equipment 1 GHz to 18 GHz;
  • requirements for robots;
  • wireless power transfer at a distance (WPTAAD);
  • radio-enabled products;
  • measurement of emissions from large or high-power equipment, including in situ.

It was also decided to start maintenance of CISPR TR 18-1 and TR 18-2. [It doesn't seem clear to the UK committee what needs to be changed.]

CISPR D (Automotive)

Decisions taken at the Plenary meeting:

  • CISPR 12 scope includes personal mobility devices (not including legs, presumably!);
  • CD to amend CISPR 25 to be issued in January 2019;
  • CISPR 36 FDIS (failed vote) will be rescued by means of a new CD, taking into account CISPR 16-4-4, in January 2019;
  • a 10-year road map is to be developed.

A request to extend a stability date might indicate a misunderstanding of the meaning of 'stability date'. It is the earliest date at which an amendment or new edition can be published. so there is no actual need to extend it.

The current projects are:

  • radiated emission limits during wireless charging;
  • frequency bands and measurement bandwidths for digital services to vehicles;
  • magnetic field emission measurements on electric and hybrid vehicles (rescue of CISPR 36).

CISPR F (household appliances tools, lighting equipment and similar)

So far, CISPR F has produced a Decision List, not the new-style Report to CISPR. Decisions include:

  • a CDV for amending CISPR 14-1, including limits for, will be circulated, while the limits will be studied in the context of CISPR 16-4-4;
  • the CDV will also include alignment of the limits for the test methods below 30 MHz, the 60 cm loop and the large loop;
  • resolution of the NC comments on the CISPR 14-2 Ed 2 A1 project;
  • radio-enabled products will be studied and taken into account;
  • CISPR 15 maintenance to begin (the DL says 'PWI', but either a DC or an RR would be expected);
  • no changes to stability dates.

CISPR H (Protection of radio services)

New liaison officers to TC77 and ITU-T SG5 were appointed. 25 very detailed action points were agreed, many of which are not interpretable without other documents.

New work items are:

  • radiated emission requirements below 30 MHz to be added to Generic standards IEC 61000-6-3, -4 and -8;
  • disturbance models for PV generators and household extra-low voltage (ELV) lighting to be added to CISPR 16-4-4;
  • conducted emission limits 9 kHz to 150 kHz to be added to IEC 61000-6-3 and -8, with priority for differential mode (DM) over common-mode (CM) [which seems strange, as DM emissions normally result in minimal radiation if there is no mode conversion];
  • disturbance model and requirements for 6 GHz to 40 GHz to be added to CISPR 16-4-4 and IEC 61000-6-3 and -8;
  • new requirements for fully-anechoic rooms (FAR), for DC power ports, and for radio-enabled products (if necessary). to be added to IEC 61000-6-3 and -8;

The international Radio Amateur Union (IARU) called attention to the rise in numbers of installed SMPS, some in operation 24 hours and some producing emissions up to 400 MHz.

IEC TC26 asks for different limits for different categories of equipment, e.g. long-term/short term operation.

Other on-going projects:

  • emission limits in FAR and reverberation chambers;
  • limits for electric and magnetic field emissions 9 kHz to 30 MHz for Generic standards;
  • emission standard for equipment in commercial and light-industrial locations [might be better expressed as 'non-household locations'];
  • height scan for emission measurements above 1 GHz.

CISPR I (ITE, MME and receivers)

New work item is to update CISPR 35 (again!).

Other future work:

  • Improvements to CISPR 32 (again!);
  • Limits below 150 kHz;
  • Increase upper frequency limit?

It is noticeable that the sub-committees differ in the amount of information reported to CISPR, even when using the new form.