Re: [PSES] Rated Mains Operating Voltage Regional Compatibility [General Use]
Thank you Bernd, Mike and everyone else who replied with your helpful comments. I think my dilemma concerns the interpretation of the rated voltage tolerance in relation to the consideration of supply voltage for testing under clause B.2.3 in IEC62368-1. The clause looks unchanged since 2014 (if not before) and reads: In determining the most unfavourable supply voltage for a test, the following variables shall be taken into account: – multiple rated voltages; – extremes of rated voltage ranges; and – tolerance on rated voltage as declared by the manufacturer. Unless the manufacturer declares a wider tolerance, the minimum tolerance shall be taken as +10 % and −10 % for AC mains and +20 % and −15 % for DC mains. Equipment intended by the manufacturer to be restricted to connection to a conditioned power supply system (for example, a UPS) may be provided with a narrower tolerance if the equipment is also provided with instructions specifying such restriction. The equipment under consideration is rated 100 to 240 Vac. This range could be seen as having a significantly wider tolerance than +10 % and −10 % depending upon what AC mains voltage you had in mind, and therefore not be subject to any further extension of tolerance according to the above rules, i.e. it would only be assessed over the voltage range 100 to 240 Vac. However, if the conventional interpretation is to apply a minimum of +10 % and −10 % to any stated voltage then the assessment would be performed over the voltage range 90 to 264 Vac. The latter seems a safer way to go but I don't know that I could assume it was tested that way and therefore not necessarily suitable for use on UK mains with its maximum toleranced voltage of 253 V. Regards, Phil -Original Message- From: Dürrer Bernd Sent: 08 May 2023 09:21 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] AW: [PSES] Rated Mains Operating Voltage Regional Compatibility [General Use] *** WARNING *** This message has originated outside your organisation, either from an external partner or the Global Internet. Keep this in mind if you answer this message. Hi Phil, The concept of rated voltage in standards already includes allowable tolerances and adequate tests. For the supply side, EN 50160 "Voltage characteristics of electricity supplied by public electricity networks" requires in clause 4.2.2 that variations of the rated supply voltage should not exceed ±10 % (with exceptions for remote grid users, e.g. on islands, where +10 % / -15 % are allowable). As Mike already explained, product safety standards require testing with the most unfavourable voltage within the tolerance band of the rated voltage of the equipment (cf. clause B.2.3 in IEC 62368-1:2018). It is the responsibility of the installer and user that the equipment is connected to a supply that matches the voltage rating declared by the manufacturer. Kind regards, Bernd -Ursprüngliche Nachricht- Von: MIKE SHERMAN Gesendet: Samstag, 6. Mai 2023 20:38 An: EMC-PSTC@LISTSERV.IEEE.ORG Betreff: Re: [PSES] Rated Mains Operating Voltage Regional Compatibility [General Use] [EXTERNAL E-MAIL] This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender. Phil -- It is typical for many standards to run voltage sensitive tests (temperature rise, for example, as I recall) at the labeled voltage PLUS a percentage (6 to 10 %, as I recall). That percentage is intended to cover the utility supply tolerances. So a product labeled 100-240 Vac will often face a test at 264 Vac. Occasionally one might find a product labeled 85-264, but in my opinion that is most likely a mistake, because it would need to be tested at 290 Vac for a standard that requires a 10% overvoltage test, and I am not aware of any supply tolerances that would allow 290 Vac. Word to the wise: Australia's nominal voltage is now 230 Vac, but it has legacy systems that still supply at 240 Vac. So a typical national difference for Australia is to perform your tests AS IF the rated voltage was 240 Vac. This means an extra test or two if you're taking a product rated for 230 Vac for the EU market and want to sell it in Australia. Mike Sherman Sherman PSC LLC > On 05/06/2023 4:09 AM CDT Agar, Philip (Leonardo, UK) > <220ac8787b71-dmarc-requ...@listserv.ieee.org> wrote: > > > Please could someone advise me on what standard, if any, might compel a > manufacturer to rate the operating voltage of their equipment to at least > cover the utility supply tolerance of the region in which it is being sold? > For example, a DoC for an IT item sold in the UK claims conformance with the > requirements of LVD Directive 2014/35/EU and EN62368-1:2014+A11:2017 but it > is not clear to me that the specified voltage rating of 100 - 240 Vac > necessarily covers UK utility supp
[PSES] Rated Mains Operating Voltage Regional Compatibility [General Use]
Please could someone advise me on what standard, if any, might compel a manufacturer to rate the operating voltage of their equipment to at least cover the utility supply tolerance of the region in which it is being sold? For example, a DoC for an IT item sold in the UK claims conformance with the requirements of LVD Directive 2014/35/EU and EN62368-1:2014+A11:2017 but it is not clear to me that the specified voltage rating of 100 - 240 Vac necessarily covers UK utility supply tolerance of up to 253 Vac, or even in much of the EU at 243.8 Vac. Thanks, Phil Agar EMC Compliance - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=1
[PSES] Non-isolated Solar Invertor EMC emissions
Background: I have been installing a recently manufactured 230 Vac 5.5 kW pure sine non-isolated solar invertor whose design exploits the PV array input operating in the same power domain as the AC mains output, i.e. no isolating transformers. Noticing that my medium wave and long wave reception was now no longer possible due to the loud hum received right through the bands, I hung an oscilloscope on the mains wiring and noticed a 300 Vpp 50 Hz square wave with sharp edges (around 1-5 us order) superimposed (common mode) upon the AC mains output. The AC mains itself is otherwise a well formed near sinusoidal 50 Hz waveform with only minor distortion at cross-over. Not wishing to cause nuisance interference to myself or others, I read the installation manual from cover to cover for guidance on EMC but found nothing and so began to try and understand how the issue might be resolved. Appreciating that the superimposed waveform might be influenced by the parasitic capacitance of the PV array relative to ground, I measured the parasitic capacitance as approximately 23 nF (this was not surprising in view of the length of underground cabling and PV array size). I then set to introduce Schaffner FN2010-30-08 filters into both the PV array input and AC mains output of the invertor but with no significant success. I am currently theorising that the level of the emission is so high that the common mode filtering inductor of this filter type is saturating. Question: Is it widely recognised that this type of invertor design is associated with high levels of EMC emissions? If so, on what basis might EMC compliance be claimed for such a unit? Perhaps there are specialist EMC filters targeted at this kind of invertor design. Phil EMC Engineer Leonardo UK Ltd Registered Office: 1 Eagle Place, St James’s, London SW1Y 6AF A company registered in England & Wales. Company no. 02426132 This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
[PSES] ESD Testing Verification Voltmeter
Hi All, I would be grateful if someone could share with me their choice of high voltage or electrostatic voltmeter when verifying calibration of ESD generator output levels under BS EN 61000-4-2:2009 / DEF STAN 59-411 Part 3 Issue 3 / MIL-STD-461G ? Best regards, Phil Agar EMC Engineer Leonardo UK Ltd Registered Office: 1 Eagle Place, St James’s, London SW1Y 6AF A company registered in England & Wales. Company no. 02426132 This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
