RE: EN 61000-3-2:2000

distortion as any other similarly loaded system in a different industry. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom

Re: UL60950: Openings in metal bottoms of fire enclosures

as per Figure 4F. Note that the drawing makes now more sense than that of the very early issues of the standard. Regards, Neil Helsby Original Message dated 24/09/2003, 19:55:17 Re: UL60950: Openings in metal bottoms of fire enclosures: Greetings All, In UL60950-00, Table 4B has the size

Re: Measurement of touch current

already mentioned, I'm not really familiar with 3-phase. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom

RE: IEC 60320 connector and cable

Thanks to all for some helpful comments, the equipment is professional. My own investigations suggested that there may not be a single cable option, but it was worth checking and in any case adds strength to my comments within the Company. Regards, Neil Helsby

IEC 60320 connector and cable

and European standards? Connectors with screw terminals having dual certification are available so why not moulded versions? Does anyone know if a combined cable having about 2m lead with both UL and European approvals is available? Many thanks, Neil Helsby

Re: earthline choke

We did some tests a little while ago with an earth line choke. This resulted in a deterioration in the EMC performance and the conclusion was that the choke represented a high impedance to RF. As the RF had to go somewhere it worked its way back into the unit under test with a noticeable

Energy-usinig Products

For those interested, the latest proposal (dated 1 August) by the EC commission for EuP can be found at http://europa.eu.int/eur-lex/pri/en/lip/latest/doc/2003/com2003_0453en01 .doc (copy this as a single line). Regards, Neil Helsby

Re: Number of Terminations on a Ground Stud?

is marked according to Section 1.7.7.1 of EN 60950. Lock nuts on the protective earthing add security and means that there is no reason to disturb the protective earth conductor during maintenance or servicing. Regards, Neil Helsby This message is from the IEEE EMC Society Product Safety

Re: Synchronizing DC-DC converters to reduce emissions?

the measurement instrument's band width of any of the other unit's harmonics, then the result may be the measurement of only one unit at each frequency of the spectrum. ok, I expect to be shown that this wouldn't work but it's worth a try! Regards, Neil Helsby

Re: LED lamps

if the product proved to be greater than Class 1, and, as a manufacturer of a consumer product, the litigation that may follow as a consequence of a user ignoring the warning and claiming eye damage as a result. Just my personal thoughts, Neil Helsby

Re: AC Power variation standard

have no difficulty in achieving these figures at criterion A (no effect) and with switch mode power supplies, continual operation at 60% dip. I hope this gives an idea of the requirements for one standard. Regards, Neil Helsby

RE: FCC's inquiry for broadband over the powerlines (BPL)

. The engineers explained that they had located the source as some overhead high voltage distribution lines strung between pylons some distance away and that they considered the problem to being a carrier with data being passed through the cables by the power supply company. Regards, Neil Helsby

Re: New Approach vs WEEE/RoHS (EuE)

You will find the draft document at: http://europa.eu.int/comm/enterprise/electr_equipment/eee/index.htm Move down to the first inset paragraph Working paperDirectiveEco-design and click on this for the pdf document. It is 18 pages long. Regards, Neil Helsby

Re: New Approach vs WEEE/RoHS

to show conformance to the requirements. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have

laser safety label

In the USA, what safety labels and/or manual information is required when a class 1 (fibre optic) device is fitted to a panel for equipment interconnection? Are the requirements the same as those for EN 60825-1? Many thanks for your assistance. Regards, Neil Helsby

Harmonics and conducted emissions

the front-end of a Spectrum Analyser that consequently requires either a pre-selector or calibrated filter to function correctly. There is, of course, the alternative of purchasing a new receiver! Neil Helsby ** This email

Re: ATEX Directive

of an ignition source!! Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error

Re: OATS building

for ALL fixings to be plastic, even the hinges. Built over a turntable facility with underground pipe (water) to feed power and signals, it worked well. Regards Neil Helsby ** This email and any files transmitted

RE: Symbols and Markings: Color scheme

I hesitate to mention an old and withdrawn British Standard ( BS 5378:Part 3) but cannot immediately find a reference to a more recent international version. this defines five sign layouts: Prohibition signs – White background, circular red band and cross bar. Warning signs – Background yellow,

Re: CE marking and additional information requirements

To quote: The CE marking must be affixed to the apparatus or data plate. Where this is not possible or not warranted on account of the nature of that apparatus, it must be affixed to the packaging, if any, and to the accompanying documents. Regards, Neil Helsby

Unity power factor

to application notes or harmonics. Anyone else have this problem? Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom

Re: Acoustic noise calculations for multiple shelves

to reflections, the measurement levels increase. Not much help I'm afraid but hope it gives food for thought. Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use

WEEE Directive

? If dangerous substances are involved in some components (as per RHoS), then they must be dealt with accordingly. Anyone with further thoughts? Regards, Neil Helsby ** This email and any files transmitted with it are confidential

Re: WEEE Directive

I think that you are looking at an old draft of the directive (2000). Go to dti.gov.uk/support/summary.htm for a draft issued 8 Nov 02 and page down to update on chnages to the WEEE. It does not have any annex, nor can I find a reference to capacitors. Regards, Neil Helsby

Re: Importance of EMC

I would endorse other postings. One important additional note is to think what it would cost if the product was found to suffer, say, excess emissions. A trip to a test-house would take one to two days to discover the problem. If the expertise of the test-house was then used to solve this

Re: Need chapter verse on NiCad ban

For all banned material log on to: www.dti.gov.uk/support/summary.htm and check out raft conciliation text for ROHS. Directives. This is the nearest official document currently available as the final form of the directive has not yet been agreed. Regards, Neil Helsby

Re: IEC 417 Protective Earth Symbol

but each should only have a single connection. All other earth ground points can be marked with symbol 5017, the one without the circle, and more than one Protective Bonding Conductor can be fixed to each point provided they are attached according to the standard. Hope this helps, Neil Helsby

ESD Testing Method

this had happened to several units, investigation showed that the oscillator's metal can was floating. The can to enclosure capacitance was such that after a few zaps sufficient charge was transferred to the can to cause an internal discharge, thereby destroying the oscillator. Regards, Neil

Re: ROHS Exemptions

was July 2006 or very soon after. Preparing now would be better than rushing around at the last minute. Lead (and some other substances) will be exempted for some products and in some restricted quantities, and these are also detailed in the Annex. Regards, Neil Helsby

Re: Ni-Cadmium Battery Belt

But do not forget that as from 1 July 2006 Cadmium is banned from the EU. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity

EMC Standards for theatrical props

in the vicinity and not forgetting magnetic fields from high powered loud speakers, it is possible that your client's product could either interfere with the theatre's installation or malfunction because of the magnetic field strengths. Regards, Neil Helsby

Re: A Different Kind of EMC Problem

. This was then being demodulated in my circuit with the resultant noise. Needless to say, the distributed dc line didn't last much longer. Regards, Neil Helsby ** This email and any files transmitted with it are confidential

RE: EU banned substances

and WEEE. If you only enter WEEE in the search box, reference to ROHS is not shown. At the bottom of the list is WEEE Directive (24/10/2002). Click on this link. Under European Union is a list with, part way down, links to both ROHS and WEEE dated November 2002. Regards, Neil Helsby

EU banned substances

that may also be of interest. Hope this helps. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed

Mercury and Europe

this relates to certain lamps and laboratory equipment. Lead is also permitted in certain specified components including CRT and radiation protection. Regards, Neil Helsby ** This email and any files transmitted with it are confidential

Ni-Cads

of these. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please

EU Directives

I have just located a useful site for up-to-date notes on the progress and status of various Directives. Www.euractiv.com Click on WEEE for the latest information including the results of last weeks agreement. Regards, Neil Helsby

WEEE RoHS

WEEE. Due to accountancy problems (accruals), agreement to consider historic waste to be addressed separately, but ahead of final publication. ROHS to be effective in July 2006 (ie lead-free delayed 6 months, all other prohibitions brought forward 6 months). Regards, Neil Helsby

Filtered D types and ground potential

equipment on the bench behind me, it drew a spark as the bnc connection was made. The engineer I worked with just laughed and found an extension block. I suspect that the benches in that lab were fed from different phases from the mains input to the building. Regards, Neil Helsby

Record retention

within the Community, this obligation is the responsibility of the person who places the electrical equipment on the Community market. Regards, Neil Helsby ** This email and any files transmitted with it are confidential

FCC 15.19 Labelling Requirements

this section of the regulations) to cover all versions or is it necessary to place a label on the optional equipment? Thanks again for your help, Neil Helsby ** This email and any files transmitted with it are confidential and intended

FCC information

ignore the frwebgate pages and is there any official document to say that would be correct? Thanks for your help, Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely

EMC prosecution UK

reputation it gives me and the friends I tell? Just my thoughts. Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed

FCC rules

Thanks again everyone for your helpful responses. The group is certainly a source of valuable help and expertise. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely

Hot surfaces

anyone know of a source of these types of labels or is this a business opening for someone? Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual

FCC routes to compliance

help. Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify

Clock frequencies and multiple postings

references to emc-pstc, the second eight references – will it ever end? Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom

Clock frequencies

. Can anyone advise on these? Many thanks, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received

Re: Screened vs. unscreened cable

, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system

translation

Using auto-translation programs can be interesting. FreeTranslation seems ok but using it to try English to German and then back to English gives: Attention – class 2 laser irradiations if opening. Stiff you in beam not. Regards, Neil Helsby

Re: Electronic Rule Compliance??

engineer would not remove this, and a few other irrelevant requirements, from the contract. So we signed the document confirming that the concrete mix in our product would meet these standards! Regards, Neil Helsby ** This email

EN 61000-3-2 Harmonics

Hi, Thanks for all the replies to my query. I am now certain of the correct procedure. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual

EN61000-3-2:2000 Harmonic current emissions

, 6.2.3.3 7 as reasons why they pass the requirements of the standard. Can anyone explain in plain English the meaning of these paragraphs with respect to the limits for class A and the measurements of individual harmonics? Many thanks, Neil Helsby

Sub harmonics

is distorted, then you need a higher power amplifier. If the amplifier can cope with this increased load, then is the 1 KHz input signal ok? Finally, check the modulation circuits. Hope this helps, Neil Helsby ** This email

RE: IEC 61000-4-2 ESD 61000-4-5 Surge lower levels

that the point in the data stream at which the discharge occured defined the effect on the product. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use

Re: IEC 61000-4-2 ESD 61000-4-5 Surge lower levels

, eventually losing output when the period was extended. The problem with investigating these types of failure is determining the size of step between measurements. Too short a step and you will be testing forever, too long and you could miss a narrow band of problem. Regards, Neil Helsby

Re: Japan mains voltage

Yes, we have experienced similar problems at some sites in Japan. This is one of the reasons why we specify our power supplies (we buy them in) to cover the range from 85 V. Regards, Neil Helsby ** This email and any

Re: EFT Capacitive Clamp

be used for the test. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email

Employment tricks

list. At this second stage, the MD would take part and select the candidate to whom the job would be offered. The manager, having decided on the engineer he wanted, proceeded to add the most unlikely candidates to this short list! Ok for him - a waste of time for the rest. Regards, Neil Helsby