Re: [PSES] Friday question

2021-06-26 Thread Richard Nute
Hi Doug: My employer had a course entitled “Zero Defects.” We were encouraged to apply it to our function. Mine, of course, was safety certification and all that it entailed. Good course as it wanted a scorecard for each activity. Using the scorecard, all my submittals went

Re: [PSES] What percentage of products pass first time?

2021-05-25 Thread Richard Nute
Hi John: “Therefore safety, standards compliance and EMC standards compliance REALLY MUST be an integral component of engineering education – and ALSO for company management…” While I agree, in practice the only time company management addresses safety and other compliance matters

Re: [PSES] What percentage of products pass first time?

2021-05-24 Thread Richard Nute
Hi Charles: Not what you asked for, but a set of principles for success with third-party testing, from a product safety point of view: 1. The design engineer and the product safety engineer should be able to predict the outcome of any test. 2. Testing simply confirms (or

Re: [PSES] Ganged Conductors in Machinery

2021-05-21 Thread Richard Nute
Hi Mark: Here’s a start: https://www.ecmag.com/section/codes-standards/conductors-connected-parallel- each-set-must-have-same-electrical https://www.electricallicenserenewal.com/Electrical-Continuing-Education-Cou rses/NEC-Content.php?sectionID=297.0

Re: [PSES] South African SABS EMC Testing

2021-05-17 Thread Richard Nute
Hi Carl: I cannot confirm that the SABS accreditation requires re-testing. However, this not unusual. I have experienced this same situation in safety testing. If a failure, the complete complement of tests is repeated on the “fixed” unit or another unit. The test house doesn’t

Re: [PSES] EU DoC on Thumb Drive?

2021-05-14 Thread Richard Nute
The symbol ISO 7000-3500 "Electronic instructions for use" is for medical equipment. The related EU regulation is: https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:072:0028:0031:EN:PDF This regulation specifies, among other requirements, “exclusive use by

Re: [PSES] Ground Bond Tests

2021-05-13 Thread Richard Nute
Hi Steve: First, one of my clients has been told by their 3rd party NRTL that a ground bond test is required as part of factory/production routine tests, even though it is not required by 61010-1. I have never run into this requirement in my work history and I would be interested in

Re: [PSES] UL Standards Effectivity Dates

2021-05-06 Thread Richard Nute
Hi Doug: In my opinion: 1. UL certifications for a particular equipment are good for the lifetime of the equipment, and don’t need to be updated… unless... 2. If the equipment is refurbished or updated, UL has a program to update the certification to the latest version

Re: [PSES] Schuko CEE 7/7 Plugs for Appliances Sold in Italy?

2021-04-29 Thread Richard Nute
See: https://www.worldstandards.eu/electricity/plug-voltage-by-country/ https://www.iec.ch/world-plugs The US Dept of Commerce used to annually publish a book with all the world plugs, but I can’t find it. Stay safe, and best regards, Rich From: MIKE SHERMAN Sent:

Re: [PSES] Determination of Maximum transient voltage on naval ships

2021-03-03 Thread Richard Nute
Hi Charlie: If the ship can be connected to shore power, then the ship may be subject to "normal" (shore-based) transient voltages, in which case your equipment must meet the clearances for 2,000 volts peak. However, the specified at-sea ship-board 1,000 volts peak is reasonable since

Re: [PSES] Electrical safety certification for US / Canada

2021-02-16 Thread Richard Nute
USA: https://www.osha.gov/nationally-recognized-testing-laboratory-program/current-list-of-nrtls Canada: https://www.scc.ca/en/accreditation/programs/product-process-and-service-certification/directory For both countries, check the standards or products for which a certification

[PSES] FW: Help with petition to be an IEEE President Elect candidate in 2021

2021-01-22 Thread Richard Nute
See following message. You must be an IEEE member to sign the petition. After you log in to your IEEE account, you will get the petition page. Click on the "Annual Election Petition," and you will get the petition page. Best regards, and stay safe! Rich -Original Message- From:

Re: [PSES] UL = IEC ??

2021-01-21 Thread Richard Nute
Hi Amund: First and foremost, both the IEC and UL make money selling standards. Second, UL does not adopt any IEC standard, or most other non-UL standards. UL will test to an IEC standard, and may issue a CB test report, but not the right to use their certification mark. UL will

Re: [PSES] NFPA Codes, law or not?

2020-10-30 Thread Richard Nute
Hi Doug: If I remember correctly, the intro to the NEC says that it is a model for adoption by various AHJs. In Oregon, each edition of NFPA 70 is formally adopted with exceptions and additions. So, most of NFPA 70 is law. The amendments are freely available. Many other

[PSES] electric shock from capacitor discharge -- late adds

2020-10-04 Thread Richard Nute
Here is a summary of capacitor discharge situations with late adds: Operator conditions: Vacuum tube radio/tv with isolated metal trim. (John Woodgate) Service conditions: Vacuum tube radar servo controller. (Doug Powell) Service conditions: UPS capacitor discharge (automatic or

Re: [PSES] electric shock from capacitor discharge

2020-10-03 Thread Richard Nute
Here is a summary of capacitor discharge situations: Operator conditions: Vacuum tube radio/tv with isolated metal trim. (John Woodgate) Service conditions: Vacuum tube radar servo controller. (Doug Powell) Service conditions: UPS capacitor discharge before servicing. (Bansi

Re: [PSES] EMF harmonised standards

2020-10-02 Thread Richard Nute
Hi Brian: Be careful that the customers’ requests are not just asking by rote. Way back when, we had customers asking about UV emissions from a crt. Most glass is a good attenuator of UV, but the asking (non-technical) customers were asking because someone in their company asked

Re: [PSES] electric shock from capacitor discharge

2020-09-29 Thread Richard Nute
with stored energy above x joules have to discharge within N seconds of power off... Cheers, -Lauren Sent from my mobile phone - please excuse typos, brevity, etc. On Sep 29, 2020, at 4:27 PM, Richard Nute mailto:ri...@ieee.org> > wrote:  I am interested in knowing what constru

Re: [PSES] Low Voltage Products and EN 62368-1 and -3

2020-09-29 Thread Richard Nute
Hi Scott: Certification is not a function of the safety standard; it is a function of the certification house. Most certification houses would be happy to certify a low-voltage product. Keep in mind that the various safety standards also address matters other than electric

[PSES] electric shock from capacitor discharge

2020-09-29 Thread Richard Nute
I am interested in knowing what constructions, situations, and products where a capacitive discharge into a body could take place. I am aware of the X and Y capacitors discharge at the prongs of a power plug. I don't immediately know of other situations or products that might discharge a

Re: [PSES] IEEE 291

2020-07-09 Thread Richard Nute
Hi John: Two questions: 1. Can an IEEE member get to see IEEE 291, even if it's only 'read only', free of charge? No. I am an IEEE member and I cannot get any free copy of IEEE 291. By the way, it was withdrawn on January 16, 2004. 2. Is its contents superseded by part of IEEE

Re: [PSES] EN/IEC 62368-1 Instructional Safeguards

2020-06-25 Thread Richard Nute
Hi Jim: IEC 62368-1 contradicts itself. In 8.5.2, the standard specifies two symbols (for moving pats). In F.5.2, the standard references graphical symbol standards, and gives the option of designing a specific symbol. So, the question is: Which sub-clause takes precedence?

[PSES] correct URLs for Canada product certification rules

2020-05-25 Thread Richard Nute
In my earlier message, the URLs got split by my e-mail program. Here are the un-split URLs: https://canada.ul.com/wp-content/uploads/sites/11/2018/05/Acceptance-of-Elec trical-Products-in-Canada-1.pdf http://www.scc.ca/en/accreditation/product-process-and-service-certification

Re: [PSES] Electrical safety testing US and Canada ... Mandatory ?

2020-05-25 Thread Richard Nute
Hi Amund: In the USA, the federal government workplace rules and most other jurisdictions require certification by a NRTL. Most certification houses are NRTL. Here is the current list of NRTLs: https://www.osha.gov/dts/otpca/nrtl/nrtllist.html All NRTLs are "approved" for the standards

Re: [PSES] 61010 vs 60601

2020-05-21 Thread Richard Nute
Hi Steve: I would think that 60601-1 certification is sufficient, and that 61010-1 is not needed. After all, 60601-1 *should be* the more severe standard. Some years ago, I certified a printer that was certified as EDP as medical equipment too. Easy. If you ask a

Re: [PSES] IEC 61010-1:2010 hazardous DC voltage

2020-03-04 Thread Richard Nute
Pete Perkins said: “A major difficulty is that the body effects are from the current while the product committees would like to specify voltage, which is easier to measure and verify compliance.” I’ve had occasion to review a number of IEC safety standards for limits on voltage and

Re: [PSES] IEC 61010-1:2010 hazardous DC voltage

2020-02-27 Thread Richard Nute
Hi Ian: The hi-pot test voltages are from IEC 60664-1, Table F.5. See IEC TR 62368-2, sub-clause 5.4.2.4. IEC 60664-1 is a “… a Basic Safety Publication intended for use by technical committees in the preparation of standards…” See Table A.1 for derivation of the withstand

Re: [PSES] IEC 61010-1:2010 hazardous DC voltage

2020-02-25 Thread Richard Nute
Hi Regan: The “bump” occurred from 1st edition, 1990, to 2nd edition, 2001. The 2nd, 2001, and 3rd, 2010, are the same. Be careful with your math and DC interpretation. The rms voltage limit is 33. The ac peak is 1.414 x 33 = 46.7. The DC is 70, which is unrelated to the AC

Re: [PSES] Mandatory certification

2020-02-20 Thread Richard Nute
Hi Regan: Yes, if that piece of equipment is not within any NRTL purview. Best regards, Rich From: Regan Arndt Sent: Thursday, February 20, 2020 1:22 PM To: Richard Nute Cc: EMC-PSTC@listserv.ieee.org Subject: Re: [PSES] Mandatory certification Hi Rich. If you

Re: [PSES] Mandatory certification

2020-02-20 Thread Richard Nute
Hi Regan: While field inspection is not part of OSHA's NRTL program, OSHA rules allow another government (federal, state, local) organization to determine compliance with the NEC. See: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.399 I would guess that such

Re: [PSES] Mandatory certification

2020-02-19 Thread Richard Nute
Hi Dürrer: 1. Self-declaration is not accepted by any jurisdiction (or by OSHA) in the USA. However, safety certification is not mandatory (or enforced) in some local jurisdictions. 2. Where the NEC is adopted by the local jurisdiction, the adoption may have exceptions and

Re: [PSES] Mandatory certification

2020-02-17 Thread Richard Nute
Hi Peter: I can only speak to NRTL certification. If your product can be used in a workplace, then NRTL certification is mandatory. In most non-workplace locations, safety certification is mandatory. A local authority specifies the acceptable certification houses. Most local

[PSES] A Radio Frequency Exposure Test Finds an iPhone 11 Pro Exceeds the FCC's Limit

2020-02-13 Thread Richard Nute

Re: [PSES] Residual Voltage Tester

2020-02-04 Thread Richard Nute
Hi Mark: Both IEC 60204-1 and IEC 60335-1 require measuring the voltage at 1 second after disconnection from the supply. Presumably, the disconnection is at the peak of the supply. Ignoring disconnection at the peak, disconnect at any time and measure the voltage at the instant of

Re: [PSES] Cable question, or 'foiled' again

2020-01-21 Thread Richard Nute
Hi Steve: I suspect that the test was set up incorrectly, especially since your client has successfully passed the test in the past, and since UL predicted failure. I would ask to replicate the test, and examine the test set-up. Good luck, and best regards, Rich Ps: See you

Re: [PSES] Touch current in IEC 60335-1 for Household Appliances

2020-01-16 Thread Richard Nute
Hi Joe: Somewhere (possibly in relation to using 60950-1), I recall that ports for connection to SELV circuits were treated as being accessible even if the connector could not be reached by the accessibility probe. This suggests that the USB connector would be treated as an accessible

Re: [PSES] Touch current in IEC 60335-1 for Household Appliances

2020-01-14 Thread Richard Nute
telecom.com <mailto:j...@randolph-telecom.com> http://www.randolph-telecom.com From: Richard Nute [mailto:ri...@ieee.org] Sent: Friday, January 10, 2020 10:05 PM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Touch current in IEC 60335-1

Re: [PSES] Class I vs Class II safety constructions

2020-01-14 Thread Richard Nute
Ortho Clinical Diagnostics From: Richard Nute mailto:ri...@ieee.org> > Sent: Tuesday, January 14, 2020 2:38 PM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Class I vs Class II safety constructions Hi Scott: I have seen no safe

Re: [PSES] Class I vs Class II safety constructions

2020-01-14 Thread Richard Nute
Hi Scott: I have seen no safety standards or codes that specify which products must be Class I and which products must be Class II, except in the USA washers and dryers must be Class I. As far as I know, the decision is that of the manufacturer. I have been associated with a

Re: [PSES] Touch current in IEC 60335-1 for Household Appliances

2020-01-10 Thread Richard Nute
Hi Joe: Electric shock requires both voltage and current. If the voltage exceeds the specified limit, the current must not exceed its specified limit. The 60335 standard as well as the 60950 standard concentrated on voltage. But, there was some recognition that if the voltage was too

Re: [PSES] Touch current in IEC 60335-1 for Household Appliances

2020-01-09 Thread Richard Nute
Hi Joe: IEC 60335-1 (2013 edition) defines a Class III product as not having any voltage exceeding SELV. SELV is defined in 335 as 42 volts rms and no-load voltage as 50 volts rms (3.4.2). Your 60 volts exceeds the 42 volts SELV limits between conductors, but does not exceed 42 volts to

Re: [PSES] [EXTERNAL] Re: [PSES] act of God versus safety

2019-12-30 Thread Richard Nute
Hi John A. and all: A different process than “risk assessment:” A hungry polar bear is a hazardous energy source. The bear’s energy exceeds John A.’s defensive energy, thus John A. can expect to be injured or worse during a polar bear encounter. The safeguard for John A. is

Re: [PSES] [EXTERNAL] Re: [PSES] act of God versus safety

2019-12-30 Thread Richard Nute
Hi Ted: I picked the reference from David Lazarus’ December 24th column from the LA Times: https://www.latimes.com/business/story/2019-12-24/acts-of-god-consumer-contract He says, “… that “acts

[PSES] act of God versus safety

2019-12-29 Thread Richard Nute
The Florida state Supreme Court ruled in 1944 that an act of God is “an act or occurrence so extraordinary and unprecedented that human foresight could not foresee or guard against it.” If a product that complies with a safety standard injures a person, is the injury an act of God?

[PSES] magnets in toys rules overturned by manufacturers

2019-12-29 Thread Richard Nute
The strategy and story of manufacturers to overcome safety rules to benefit their sales (long):

Re: [PSES] Fire enclosure IEC/EN61010 - flammability classification

2019-12-09 Thread Richard Nute
Hi Amund: Yes. See IEC 61010-1 2010, 9.3.2 c) 2). Best regards, Rich From: Amund Westin Sent: Monday, December 9, 2019 3:46 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Fire enclosure IEC/EN61010 - flammability classification * Moveable equipment (4 pcs

Re: [PSES] HV relay

2019-11-25 Thread Richard Nute
Dear Boštjan: As you know, a relay, including a vacuum relay, has two circuits. One is the coil that controls the contacts. The other is the contacts. Usually, these are separate circuits. If the one of the circuits provides a safeguard function, then the two circuits must meet

[PSES] Why China Is Dominating Lithium-Ion Battery Production

2019-11-12 Thread Richard Nute
https://www.forbes.com/sites/rrapier/2019/08/04/why-china-is-dominating-lith ium-ion-battery-production/#2b9d77883786 "According to the research organization BloombergNEF, the volume weighted average lithium-ion battery pack price (which includes the cell and

[PSES] FCC regulatory statements

2019-10-31 Thread Richard Nute
“This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation” Hmm.

[PSES] The Consumer Electronics Hall of Fame: BRK First Alert Smoke Alarm

2019-10-30 Thread Richard Nute
GbVptSXhOekZpWWpOayIsInQiOiJ0T3dTaTdXTUFMeWNXK0ZJOXhwNlF4ZkgxT0JPNWN1UXhzV1B 1TmVoNWVFR2FCMVFHNk1TbVlrcDR4Y2lFa0M3ZTJ1WFFxdkJwOElmaW44cVlCTmtka0lIWHZ0XC9 cL0JlMmlGT0VJZGZHRWtmMDBOUnRlT3BpYjVSaTBjNW9UdFoyIn0%3D Best regards, Richard Nute Bend, Oregon

Re: [PSES] EN 61010-1 accessible Energy Hazard

2019-10-17 Thread Richard Nute
Hi Charlie: Is there a clause/requirement in 61010-1 similar to 60950-1 clause 2.1.1.5 where a SELV source >240 VA is not permitted to be accessible in an Operator Area I could not find this requirement in 61010-1, 3rd edition. The 240 VA requirement does not insure safety due

Re: [PSES] Do We Need Flame Retardants in Electronics?

2019-10-01 Thread Richard Nute
ood therefore bad practice. Thanx for bring this around again. :>) br, Pete Peter E Perkins, PE Principal Product Safety & Regulatory Affairs Consultant PO Box 1067 Albany, Ore 97321-0413 503/452-1201 IEEE Life Fellow <mailto:p.perk...@ieee.org> p.perk...

[PSES] fire enclosure requirements for small Lithium battery

2019-09-30 Thread Richard Nute
"Many manufacturers consider outer tape around battery, that's meet min. V-1, as fire enclosure." This construction may meet the letter of the standard, but is not effective as a fire enclosure. If the battery overheats, it will melt the tape and. Best regards, Rich -

Re: [PSES] Grounding of metal cabinet

2019-09-24 Thread Richard Nute
The problem of board-mounted AC inlets is not limited to the ground connection. Board-mounted AC inlets often have strain applied to them by the enclosure. This strain is transmitted to the soldered connections to the board. Solder cold-flows, and is basically unable to provide a

Re: [PSES] AW: [PSES] Do We Need Flame Retardants in Electronics?

2019-09-18 Thread Richard Nute
jority has supplied such data. As general source of reference to identify substances typically used as flame-retardants I recommend the IEC 62474 Declarable Substance List at http://std.iec.ch/iec62474. Kind regards, Bernd Von: Richard Nute Gesendet: Dienstag, 17. September 2019 01:00 An

Re: [PSES] Do We Need Flame Retardants in Electronics?

2019-09-16 Thread Richard Nute
of illness and injury from the chemicals themselves and disposal of the products. Rich On Mon, Sep 16, 2019 at 2:32 PM Richard Nute mailto:ri...@bendbroadband.com> > wrote: <https://www.scientificamerican.com/article/do-we-need-flame-retardants-in-electronics/

[PSES] Do We Need Flame Retardants in Electronics?

2019-09-16 Thread Richard Nute
https://www.scientificamerican.com/article/do-we-need-flame-retardants-in-el ectronics/ ".there has never been any valid statistical demonstration that flame retardant chemicals of the types and concentrations used in consumer products have resulted in death or injury reduction," says Vytenis

Re: [PSES] Branding Products and EU Decision 768 NLF

2019-08-15 Thread Richard Nute
Hi The Other Brian: “Company-A's name and address is on the Nameplate Label on the back of the Widget. Company-A handles everything including the Conformity Assessment, Generating the EU-DoC, Applying the CE marking, audits, inspections, etc..” All of the other markings and stuff

[PSES] committee member motivations

2019-08-10 Thread Richard Nute
Regarding the standards... standards are written by guys like you and me. Experts in the WG and national committees are not paid for their knowledge (which actually is one of the finest on the planet !) , and many of them will confirm that they (or their employer) actually need to pay to

Re: [PSES] Product safety leading edge

2019-07-27 Thread Richard Nute
r. 10. New concepts in medical products. Best regards, Richard Nute IEEE Life Fellow Bend, Oregon, USA On 7/26/2019 7:13 AM, David Schaefer wrote: All, As an EMC engineer I’m aware of new technologies and challenges in EMC testing - 5G and IoT, time domain measurements, risk management,

Re: [PSES] IEC 61010-1 & leakage current

2019-07-25 Thread Richard Nute
Hi Chet: IEC 61010 doesn't use the term "leakage current" (or the IEC 60990 term "touch current.")  Instead, it uses "hazardous live."  The values are in 6.3.1 and 6.3.2.  These same values are valid for the USA and Canada (because there are no national differences for North America).  Note

Re: [PSES] UL 61010-1 7.4 stabilty

2019-07-22 Thread Richard Nute
Hi Doug: See IEC 61010, 3rd edition, Clause 7.4 d) and e). The 4X load is only applied to the support or castor that has the greatest load (independent of the equipment) (d).  I guess the pass criterion is no failure of the support or castor.  (If the support or castor is rated 4X or more

Re: [PSES] Ground on ship

2019-07-14 Thread Richard Nute
For us safety nerds, grounding provides an equipotential environment, which means no current through the body.  And, the grounding circuit provides a return path for fault current.  We don't pay attention to Gnd0, Gnd1, Gnd2, Gnd-Iso, etc.; for safety purposes, they are all at the same

Re: [PSES] Ground on ship

2019-07-13 Thread Richard Nute
Hi Bill: On 7/13/2019 10:42 AM, Bill Owsley wrote: They started out, and still in some rural areas, use earth as the "ground" for the return of the AC power being provided to users. The descriptive term is "SWER,"  Single Wire Earth Return.

Re: [PSES] Ground on ship

2019-07-08 Thread Richard Nute
Hi Peter: Sea water is a very good conductor, better than soil.  Fresh water is an okay conductor.  Pure water is a poor conductor. The hull of a steel ship is well grounded in the ocean, and reasonably well grounded in fresh water due to the large contact area with the water. If the hull

Re: [PSES] Tilt stability and CoG test lab

2019-07-05 Thread Richard Nute
Hi Frank: In most cases, the COG is near or at the geographic center of the equipment.  This would be at the half-way point of each dimension, W, L, H.  For your product, the worst-case tip-over would be on the W (5 feet) side. Expanding on Doug's suggestion, tip the unit on each bottom

Re: [PSES] Guidelines v Standards v Codes

2019-06-27 Thread Richard Nute
Hi Doug: Way back when, Dwaine Richins, professor at University of Oregon, taught that a standard was “a statement of acceptable performance.” Keeping this definition in mind… Laws enable a government agency to generate regulations, codes, or even standards. An electrical code is a

[PSES] test message

2019-06-27 Thread Richard Nute
I had to reinstall my e-mail app, so this is a test whether I set it up so I can post to the listserver. Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to

Re: [PSES] Grounding

2019-06-18 Thread Richard Nute
Hi Steve: I disagree with my colleagues. You didn’t say how the mains was distributed from the first module to the second and third modules. I have assumed the mains is also distributed by the Wago/Din rail scheme. If this is the case, then I would say the grounding can also be

Re: [PSES] Tilt test

2019-06-12 Thread Richard Nute
Hmm. * The equipment is tilted in all directions such that the base of the equipment is at an angle up to and including 10°; or Only one direction is significant: The side of the base that is closest to the center of gravity. This is the worst case. If the equipment passes this

Re: [PSES] Stacking Grounds on a Stud

2019-06-07 Thread Richard Nute
Hi Brian: As you know, my opinions are engineering-based, not standards-based. The rule (or principle) is that the main protective grounding (of the power cord) need not be disturbed when servicing the other stacked ground circuits or assemblies on a stud or stud-equivalent. This

Re: [PSES] 62368-1 Openings in a fire enclosure

2019-05-26 Thread Richard Nute
combustible material so according to the standard it’s V-1! I’m sure the interpretation will vary between different facilities and it’s still early days for application of 62368-1. Best regards, Glyn From: Richard Nute mailto:ri...@ieee.org> > Reply-To: mailto:ri...@ieee.org&g

Re: [PSES] 62368-1 Openings in a fire enclosure

2019-05-22 Thread Richard Nute
Hi Glyn: You have the option of testing the bulkhead connectors in place (Annex S.1). Apply the test flame to the inside surface of the installed connector material at a point judged to be likely to become ignited because of its proximity to a source of ignition. I suspect your product

Re: [PSES] GB or GC?....that is the question....

2019-05-22 Thread Richard Nute
at the facts another way. Since the test is passed, provided the fault does not get worse, the product remains safe. It's not an ideal situation, but it seems that something like a 100 A test would be required in order to detect a fault of either type described. On 2019-05-22 17:28, Richard Nute

Re: [PSES] GB or GC?....that is the question....

2019-05-22 Thread Richard Nute
Hi Regan and all: As I’m sure you know by now, I subscribe to engineering principles, not to the various safety standards. Some years ago, I did some tests to determine the better production-line test for the grounding circuit. I documented my findings in an article in the Product

Re: [PSES] 62368-1 Openings in a fire enclosure

2019-05-17 Thread Richard Nute
Hmm. Interesting English usage statement. If something fills an opening, the opening no longer exists. So, how do you know how to apply the requirement? Rich From: Payne, Glyn <0d283c0acebb-dmarc-requ...@ieee.org> Sent: Friday, May 17, 2019 6:40 AM To:

Re: [PSES] Question re: Measuring a signal in a noisy environment

2019-04-18 Thread Richard Nute
Yes, EMC and safety must be designed in. It follows that the person who designed it in must also be able to predict the test outcome. If the test outcome is not as predicted, either the test was wrong or the prediction was wrong. In my experience (safety), the test house would like

Re: [PSES] Tamper-proof Hardware

2019-04-09 Thread Richard Nute
carried out. Best wishes John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> Rayleigh, Essex UK On 2019-04-09 19:04, Richard Nute wrote: Standards need not – indeed should not -- address nefarious activity on the part of th

Re: [PSES] Tamper-proof Hardware

2019-04-09 Thread Richard Nute
o." Molière On 9-Apr-19, at 14:04, Richard Nute mailto:ri...@ieee.org> > wrote: Standards need not – indeed should not -- address nefarious activity on the part of the user. And, standards need not address tampering (defined previously) as there can be no end to the extent of tampe

Re: [PSES] Tamper-proof Hardware

2019-04-09 Thread Richard Nute
Standards need not – indeed should not -- address nefarious activity on the part of the user. And, standards need not address tampering (defined previously) as there can be no end to the extent of tampering. The requirement for “tamperproof” is beyond the scope of safeguarding a user

Re: [PSES] Tamper-proof Hardware

2019-04-08 Thread Richard Nute
>From dictionary.com: tamperproof adjective 1 that cannot be tampered with; impervious to tampering tamper verb (used without object) 1 to meddle, especially for the purpose of altering, damaging, or misusing (usually followed by with ) 2 to make changes in something, especially

Re: [PSES] Tamper-proof Hardware

2019-04-08 Thread Richard Nute
In IEC 62368-1, Basic Safeguards provide protection under normal conditions. Supplemental Safeguards provide protection under fault conditions, including a fault of the Basic Safeguard. Supplemental Safeguards ARE required. I have seen folks who say that the standards represent

Re: [PSES] classification of the output

2019-03-15 Thread Richard Nute
Hi Mick: In 1961, James J. Gibson published a paper entitled “The contribution of experimental psychology to the formulation of the problem of safety: a brief for basic research.” This paper reported his studies of injury causation in automobile accidents: “Injuries to a living

Re: [PSES] classification of the output

2019-03-13 Thread Richard Nute
Hi Boštjan: If you say ES1 and another certification body says ES2, then a negotiation must take place. To avoid negotiation, you must change your verdict to ES2. However, the manufacturer wants ES1, which is determined by the voltage. I agree that the voltage waveform is ES1

[PSES] human skin resistance

2019-03-13 Thread Richard Nute
John referenced “skin resistance.” To my knowledge, there is no research that shows skin resistance and body resistance as separate parameters. We only know total body resistance, and that it is a variable that changes – lowers -- with applied voltage and time. Having said that, a

Re: [PSES] classification of the output

2019-03-12 Thread Richard Nute
Ted has proposed something that safety standards committees do not do: EXPERIMENTS to prove or disprove the requirements. But I have done voltage, current, and thermal experiments on students (voluntarily) at the Energy Class 1 levels in my HBSE courses. One of the more

Re: [PSES] classification of the output

2019-03-08 Thread Richard Nute
Hi Boštjan: Following up on my previous comment. Chances are the IEC 60990 touch current measurement scheme will not have a steady state current, but instead a fluctuating current. Especially if the PS output has a source impedance during the "off" state, which would discharge the

Re: [PSES] Brexit and impact on official languages

2019-03-08 Thread Richard Nute
Note that the U.S.A. does not have an “official” language, but English is predominant and is used for most government and other documents. Occasionally, someone will get a burr and propose that we adopt English as our “official” language and stop catering to non-English-language folks.

Re: [PSES] CEE standards?

2019-03-07 Thread Richard Nute
/refdocs/ Best wishes John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> Rayleigh, Essex UK On 2019-03-07 19:18, Richard Nute wrote: Hi John: I asked IEC. No response. Best regards, Rich From: John Woodgate <

Re: [PSES] CEE standards?

2019-03-07 Thread Richard Nute
catalogue.:-) Best wishes John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> Rayleigh, Essex UK On 2019-03-07 17:38, Richard Nute wrote: I'm looking for CEE standards, or a catalog of CEE standards. CEE is "Commission for Conform

[PSES] CEE standards?

2019-03-07 Thread Richard Nute
I'm looking for CEE standards, or a catalog of CEE standards. CEE is "Commission for Conformity Testing of Electrical Equipment." CEE was superseded by IECEE, IEC System of Conformity Assessment Schemes for Electrotechnical Equipment and Components. The standards are no longer available, but

Re: [PSES] Type F receptacle wiring

2019-02-22 Thread Richard Nute
inions Only J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> Rayleigh, Essex UK On 2019-02-22 23:14, Richard Nute wrote: Hi Doug: The French, Belgian, and Schuko domestic connectors are non-polarized. The British, North American, South Africa, some Japan domesti

Re: [PSES] Type F receptacle wiring

2019-02-22 Thread Richard Nute
Hi Doug: The French, Belgian, and Schuko domestic connectors are non-polarized. The British, North American, South Africa, some Japan domestic connectors are polarized. Some domestic connectors in Norway and many in Japan have no PE. Wikipedia discusses the various plugs and

Re: [PSES] Rating & WEEE markings on lithium-ion rechargeable battery

2019-02-22 Thread Richard Nute
Hi Dave: Yes. Coffee makers and other consumer electric-electronic products are not repairable by an ordinary user. If it was, a parts list would be included. When the product quits working, it is end of life. The fact that you replaced a part in a non-repairable device is

Re: [PSES] Rating & WEEE markings on lithium-ion rechargeable battery

2019-02-22 Thread Richard Nute
lers. If there is no marking, is it safe to replace the right battery? Do we need to take it into the risk assessment? Thanks and regards, Scott On Thu, 21 Feb 2019 at 02:53, Richard Nute mailto:ri...@ieee.org> > wrote: Hi Scott: I agree with John. All batteries wear out.

Re: [PSES] Rating & WEEE markings on lithium-ion rechargeable battery

2019-02-20 Thread Richard Nute
Hi Scott: I agree with John. All batteries wear out. A battery is replaceable either by the user or by a serviceman. For this reason, the battery (or the product or both) must be marked so that the battery can be replaced by an identical or equivalent battery. Same as the

Re: [PSES] Johnson City NY - crazy street lights

2019-02-04 Thread Richard Nute
Hi Doug: “… DMX512 is not two-way communications as such and would not be able to report a defective fixture needing maintenance…” Where I live, the street lights are controlled individually by light sensors. When a light burns out, we residents report it to the city (feedback

Re: [PSES] Johnson City NY - crazy street lights

2019-02-04 Thread Richard Nute
Hi Doug: Each individual light is blinking at its own pace. You can see this by pausing the video; at each pause, some lights are on, while some are off. (At first, I thought they were blinking in sequence, but you can see that this is not the case by pausing the video at different

Re: [PSES] AW: [PSES] Source for Nameplate Rating Nomenclature

2019-02-01 Thread Richard Nute
Hi Brian: We have three standards, one for the manual, and two for the product (the product standard and the general standard, IEC 61293). The mains ratings display differ among the standards. Your products must adhere to the product standard. If no marking requirements are in

Re: [PSES] Brexit requirements for UK manufacturers.

2019-01-23 Thread Richard Nute
The CE mark is a first-party certification mark. It means the manufacturer believes the product complies with all applicable EU directives and has documentation to prove compliance. (The EU requires compliance to applicable directives.) Manufacturers all over the world who do

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