Re: [PSES] input current rating

2015-05-17 Thread Rich Nute
Dear Bostjan: One of the uses of current rating on equipment is to determine that the equipment, with all of the other equipment, would not overload the mains circuit. If the actual current exceeds the marked current, then the equipment, with all of the other equipment, can overload the

Re: [PSES] UL 60950-1 clause 2.2.3

2014-09-08 Thread Rich Nute
Subject: Re: [PSES] UL 60950-1 clause 2.2.3 In message f6d1e59f218e.540c8...@bendbroadband.com, dated Sun, 7 Sep 2014, Rich Nute ri...@bendbroadband.com writes: I believe the authors of 60950-22 expected that user-accessible parts would comprise SELV circuits rather than grounded parts

Re: [PSES] UL 60950-1 clause 2.2.3

2014-09-07 Thread Rich Nute
Hi John: I believe the authors of 60950-22 expected that user-accessible parts would comprise SELV circuits rather than grounded parts. See 2.1.1 and 2.2 in 60950-1. Grounded parts would be subject to 5.1 in 60950-1. Best regards, Rich - Original Message - From: John Cochran

RE: RF What-if (was: RE: Another Cancer Scare?)

2008-08-06 Thread 'Rich Nute'
Back in the old days -- say mid-50's or earlier, broadcast transmitters were required to be monitored full-time by a qualified engineer. High-power AM transmitters bombarded these guys with all kinds of stuff. Many of these old-timers reported effects on the brain, but I can't remember the

RE: IEC 62368

2008-07-21 Thread 'Rich Nute'
Hi Brian: 1. What is the status of IEC62368 and the associated and infamous IEC62441 ? Ultimately, when are 60950-1 and 60065 projected to be replaced by 62368 ? CDV2 will be issued to National Committees for voting this or next month. (You can get a copy from your National

RE: A Disk To Reduce EMI from Cell Phones?

2008-07-05 Thread 'Rich Nute'
Hi Scott: So, I went to the web sites you cited. Then, I went to the citations. For one of the citations, the abstract says: Levels of DNA single-strand break were assayed in brain cells from rats acutely exposed to low-intensity 2450 MHz microwaves using an alkaline microgel

CCC processes

2008-07-01 Thread 'Rich Nute'
Is there a good document (in English) on CCC processes? How to do it? Are there any agents in England who can assist or get CCC? Thanks for your help, Richard Nute San Diego - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website:

RE: like your eggs raw /// mobile phone safety

2008-06-19 Thread 'Rich Nute'
Six Parisian libraries have already been the subject of a campaign of measurements of electromagnetic waves, showing that electric fields were 80 to 400 times below the regulatory limit. The city is aware of concerns and wants to remain vigilant, said Anne Hidalgo, the first deputy

RE: 60950-1:2006 clause 2.5 - Limited power sources

2008-06-19 Thread 'Rich Nute'
Hi Jim: I don't understand why electromechanical devices cannot be proven to have reliable cycle life. There are electromechanical devices tested for 6,000 cycles and 100,000 cycles commonly available, and there may be other classes with even higher cycle life. For a circuit-breaker,

Turkish Tabloid -- Spiegel -- Sober -- a brief explanation

2005-05-19 Thread Rich Nute
Since May 16, worldwide spam messages have been sent containing links to the Spiegel web site. One of those messages found its way to emc-pstc. The spam uses a variant of the mass-mailing worm Sober. This worm taps into inboxes and then sends out infected mail to everyone listed. If

Virus confirmed,

2004-08-09 Thread Rich Nute
With thanks to Jim Eichner, the virus is confirmed. Delete the message from RPICKARD. For a complete description of the virus, see: http://vil.nai.com/vil/content/v_127423.htm Note that it spoofs the sender. Also note that the virus was discovered today, August 9. Perhaps that is why

Re: Security Problem?

2004-08-09 Thread Rich Nute
Please treat the attachments to Ron Pickard's message as a virus. At the moment, we cannot confirm whether the attachment contains a virus. The file passed through the IEEE virus filters, which are *VERY* good. Also, at least one subscriber checked the files with Norton and did not

emc-pstc Administrative Message

2004-04-14 Thread Rich Nute
to post messages to emc-pstc. I'm sure you've noticed in recent postings that the IEEE provides effective virus protection. This will continue. Best regards, Rich Nute, emc-pstc co-administrator Jim Bacher, emc-pstc co-administrator

Re: How do I do this test?

2003-12-01 Thread Rich Nute
Hi Vic: I have a Class 1 product. It has a double insulation barrier between Primary and earthed SELV, and basic between primary and the metal enclosure. How can I perform an electrical strength test across the primary/SELV barrier? The construction you describe has two

Re: EN 61000-3-2:2000

2003-11-10 Thread Rich Nute
Hi Josh: This standard has been adopted by China and Japan. Japan has added a source impedance for the test setup, but it implies to me that this is a world-wide issue. The question I was attempting to answer was John's question if 61000-3-2 is not an EMC standard, then what kind of a

Re: EN 61000-3-2:2000

2003-11-10 Thread Rich Nute
Hi John: Some have questioned whether 61000-3-2 is even an EMC standard! If not, what do you think it is? I fall into the group that question whether 61000-3-2 is an EMC -- Electo-Magnetic Compatibility -- standard. The objective is to prevent reduction of peak voltage on the

Re: Class 1 AC/DC adapter

2003-11-06 Thread Rich Nute
Hi Peter: The body shape and dimensions, the pin sizes shapes, dimensions and orientations where they interface with an appliance coupler I know are defined. I don't have copies of all of the IEC60320 documents and am unaware that the product interior side of the appliance

Re: Class 1 AC/DC adapter

2003-11-06 Thread Rich Nute
Hi Peter and Raymond: To verify the veracity of my memory, I went to my lab and took two manufacturer's C14 appliance inlets and applied 5kVac from both poles to the earthing terminal for 7 mins. each, with the instrument sensitivity adjusted to its maximum (eg, minimum

Re: Class 1 AC/DC adapter

2003-11-06 Thread Rich Nute
Hi Peter and Raymond: In the sake of fairness, it should be noted that both of my EUTs had solder loops and were not intended for surface or through-hole mounting to a PWB. For the sake of our mutual edification, it would be interesting to see how the appliance inlet in

Re: Class 1 AC/DC adapter

2003-11-05 Thread Rich Nute
Hello Chengwee: Whether customer can accept his adaptor with only 1500Vac hipot tested where other power supplies can withstand 3000Vac? This is an interesting question as it implies that the higher the withstand voltage the better the unit. The statement may even imply that a

Re: Class 1 AC/DC adapter

2003-11-05 Thread Rich Nute
Hi Peter: I have and continue to advocate (in IEC TC 108) that such classes should apply to CIRCUITS, not to products. If this is endemic in IEC (as your statement implies), it may require a elephantine effort. Good luck. Yes. And thank you. The IEC Class I and

Re: Class 1 AC/DC adapter

2003-11-04 Thread Rich Nute
Hi Chengwee: In my years working in power supply industry, I have never done the ground continuity test between Earth terminal to the DC output for adaptor. Normally I wouldn't trust the PE path with anything less than 18AWG or equivalent. There are two kinds of tests that I

Re: Class 1 AC/DC adapter

2003-11-04 Thread Rich Nute
Hi Peter: No where does the standard state that by simply providing a Functional Earth, even through an appliance inlet (implying use of a power supply cord), the equipment is not considered Class II. One is simply limited to not marking with the aforementioned symbol.

Re: Class 1 AC/DC adapter

2003-11-04 Thread Rich Nute
Hi John: I do have one question for the group just for my own knowledge...back in my TUV days I worked almost exclusively with IEC60950 and seem to remember that a class II product can have a functional earth connection provided Primary and other hazardous voltages are insulated

Re: Class 1 AC/DC adapter

2003-11-04 Thread Rich Nute
Hi Raymond: If the dc output is connected to the PE terminal, then the dc output could become live in the event of a fault in the basic insulation between mains and the PE terminal. I think it may not be the case in practice. Even the dc output is connected to the

Re: Class 1 AC/DC adapter

2003-11-03 Thread Rich Nute
Hi Raymond: 1. Earth continuity test As the class 1 is due to the additional earthing plate, how can I ignore the earth continuity test? Class I is due to the adapter having an appliance coupler with a PE terminal. Without this earthing plate, the unit is in fact a class 2

Re: Class 1 AC/DC adapter

2003-11-03 Thread Rich Nute
Hi Chengwee Lai: 2. Earth Continuity or ground bond testing with 25A or higher is not applicable with plastic case and not applicable at the DC output side. It was meant to check the earth protection continuity of a metal chassis. Protective earthing is required for any conductive

Re: Class 1 AC/DC adapter

2003-11-03 Thread Rich Nute
Hi Raymond: Any product with a PE (ground) connection is, by definition, a Class I product. The common adapters you describe, despite being encased in plastic, are Class I products. 1. Function of the grounding plate The primary and the secondary is reinforced insulation and

Re: FW: Y caps

2003-09-30 Thread Rich Nute
Hi Brian: Does a cap rate Y2 IAW EN132400 and IEC 60384-14 meet all requirements for the UL CCN for EMI filters (FOKY2, UL1414)? Only if the Y-cap bears the UL mark. Look for the mark on the cap. Is the UL CCN FOKY2 based on UL1283? UL 1414 applies to capacitors which can be

Re: Impulse for Hi-Pot

2003-09-29 Thread Rich Nute
Hi Bryan: I have a request from the design community to implement a routine impulse test in lieu of a Hi-Pot test. This product is evaluated to 61010-1 and the reason for the request is that a measuring circuit connected to the affected output circuit contains a resistor string

Re: Hi-Pot testing

2003-09-19 Thread Rich Nute
Hi Sam: Correct me if I'm wrong, but the point of the type-level hipot test is not to simulate a real-life condition (like surge protection), but to simulate years of insulation degradation, which happens with or without surge protection. I disagree. Primary circuits are subject

Re: Hi-Pot testing

2003-08-28 Thread Rich Nute
Hi Chris: During safety testing at the lab, the unit passes HiPot testing. However, the unit is broken by the testing. Rigorously, the unit passes its type testing because it doesn't become unsafe by the Hipot. However, it isn't functional after the test; and it

Re: fuse replacement markings

2003-08-27 Thread Rich Nute
Hi Peter: Is anyone aware of any CTL decisions for IEC60950:2000 or -1, where operator accessible fuse replacement marking requirements may be waived, based on the fuse not being required for safety reasons (did not open during any test under any conditions of test) and where of the

Re: 94V-0 question

2003-08-12 Thread Rich Nute
Hi Dave: I need a sheet of plastic that goes between a PCB and a metal enclosure. This is to make a creepage spec. What plastics are good for this? Will polycarbonate be suitable and have a 94V-0 rating? With respect to IEC 60950... A plastic material used as an electrical

Re: NARTE safety engineer certification

2003-07-02 Thread Rich Nute
Hi Peter: Out of curiosity, I wrote NARTE directly regarding the below, to see what benefit they believe NARTE certification would offer someone who already has experience in product safety and a PE Registration. It's been a week and they have not responded. Perhaps that's

Re: The transformer screen/shield conundrum

2003-07-01 Thread Rich Nute
Hi John: If the breakers are 230 V/16 A and 120 V/15 A, then the power distributed at 230 V is roughly twice that at 120 V. But your '120 V' is also '240 V' for some equipment. Besides, I think I was being 'generous'; electrical energy consumption per head in USA is

Re: The transformer screen/shield conundrum

2003-06-30 Thread Rich Nute
Hi John: For 3% voltage drop at maximum rated load, the source resistance is about 0.2 ohm. So the maximum rms current would be system nominal voltage divided by 0.2 ohm, or 600 amps for 120 V and 1150 amps for 230 V. For 230V, there are two modifications. One is

Re: The transformer screen/shield conundrum

2003-06-28 Thread Rich Nute
Hi Richard: You mention a few times the 25 Amp test. The designs I have seen that try and use this approach (and I don't ever recall seeing a design I was happy with) were all switch mode power supplies where there was an input fuse of about 2A, meaning that the test would be

Re: CE without LVD?

2003-06-28 Thread Rich Nute
Hi David: In regards to your suggestions below, would it not be wise to take into consideration the future plans of the LVD? The original question was specific to the LVD. My response was specific to the LVD. You raise a new question with regard to a future EU directive, the

The transformer screen/shield conundrum

2003-06-28 Thread Rich Nute
Hi John and Richard: The transformer screen/shield between primary and secondary windings is intended to carry the fault current in the event of a failure of basic insulation between the primary and the screen/shield. The screen/shield must be capable of carrying the full fault current and

Re: CE without LVD?

2003-06-27 Thread Rich Nute
Hi David: It is being suggested that this product does not need safety testing and does not need to include the reference to EN 60950 and the LVD in the CE DoC, since it is SELV circuits only. The LVD applies to products with voltage ratings between 50 and 1000 V ac and between

Re: PCB marked for UL 94V-0

2003-06-19 Thread Rich Nute
Hi Doug: The question is, how do I independently validate the material used, since a vendor could theoretically choose whatever they want and stamp it as V-0? I interpret your question as to how to determine whether or not a PCB is counterfeit or not. A UL-certified PCB would have

Re: Bad Fuse vs. Good Fuse

2003-05-27 Thread Rich Nute
Hi Dan: Thank you for giving us straight answers and helping us to overcome the conventional wisdom about fuses. Several years ago, I put together an article addressing fuses, their operation, and how to select the fuse rating. See: http://www.ewh.ieee.org/soc/emcs/pstc/psn/ Then,

Re: Safety testing after equipment repair

2003-05-23 Thread Rich Nute
Hi Richard: is the below information true for both the AC and DC hipot methods? Some companies have contractors,subcontractors, incoming and final hipot... so it does and can occur at least 4 times, before its shipped to a customer. The theory says that the onset of the

Re: Safety testing after equipment repair

2003-05-23 Thread Rich Nute
Hi John: There is a justification for a high-current test **where it won't cause any new damage**. The justification is that it will find bad joints in the PEC path, and stranded PEC and bond wires that have only one or two strands still intact. The high-current test will NOT

Re: Safety testing after equipment repair

2003-05-23 Thread Rich Nute
Hi John: I don't think you can draw universal conclusions from just one experiment. In addition, the rate of increase of voltage is limited in the test procedures. In your experiment, there was only one increase of voltage, whereas in repeated testing, there are many. At best, we

Re: Safety testing after equipment repair

2003-05-22 Thread Rich Nute
Hi John: My last (3) employers have required all repaired or modified units to be hi-potted. If a unit has been repaired, then the cover was removed, and the unit is no longer controlled by the oroginal production hi-pot. I think this is too stringent.

Re: Safety testing after equipment repair

2003-05-22 Thread Rich Nute
Hi Gregg and Barry: Australia has an actual standard which lists the tests and procedures for the regular testing of equipment in use, and equipment that has been So has the UK. it was called (something like) The Electricity at Work Act generally a good thing put a dangerously

Re: Glow Wire test vs. UL94 - flammability rating

2003-05-19 Thread Rich Nute
Hi Ilan: I was looking for a viable comparison between glow wire and the UL94 flammability rating. The point of this little comparison is to bypass the glow wire test for materials, which are properly rated for UL94. There is no comparison between the glow-wire test and the flame

Re: reinforced insulation - EN60950

2003-05-08 Thread Rich Nute
Hi Alexandru: 1. Is the combination of Basic Insulation + FuseTransorb(15V) equivalent to Reinforced Insulation? No. The scheme of protection against electric shock relies on passive devices, not active devices. As a general rule, active devices, e.g., transorb, are not allowed as

Listserver delays -- Re: reinforced insulation - EN60950

2003-05-08 Thread Rich Nute
Strange behavior of the list-server. Although I got some out-of-office replies, neither I or my fellows in the office (members of the list) have received the message posted 24 h ago. I'll try again... We are still experiencing delivery problems from the listserver. The IEEE gurus

Re: DERIVATION OF CREEPAGE AND CLEARANCES

2003-04-28 Thread Rich Nute
Hi Gordon: Does anyone know from where the values for creepage and clearances given in EN61010-1 (safety requirements for electrical equipment for measurement, control and laboratory use - part 1 general requirements) are derived i.e. are there other standards below 61010 in this

Re: Symbols vs. text - was EN61010-1, Symbol 14 - validation

2003-04-25 Thread Rich Nute
Hi Pete: This usually means developing a focus group and getting them to pick it out of a group of symbols when asked to identify the symbol for 'XXX'. I take this to mean that the group is given the definition and then asked to identify the symbol that matches the definition.

Re: Symbols vs. text - was EN61010-1, Symbol 14

2003-04-19 Thread Rich Nute
Hi Richard: Products should be designed so that no safety symbols/words are required (at least for the user/operator). A very laudable viewpoint and one that is easily achievable in the examples you provided. However, with certain products there has to be a residual

Re: Symbols vs. text - was EN61010-1, Symbol 14

2003-04-18 Thread Rich Nute
Hi Richard: You said We in the product safety industry must be very careful that we use symbols in strict accordance with their definitions. No issue with you there. However, the paper states that some of these misuses were perpetrated by people not even connected with

Re: EN61010-1, Symbol 14

2003-04-17 Thread Rich Nute
Hi Richard: As you say, this web site provides a discussion on the exclamation symbol. However, the discussion is slanted in one direction that not everyone in the safety fraternity would necessarily subscribe to. For instance, I have seen the 'high voltage flash' sign used as a

Re: EN61010-1, Symbol 14

2003-04-14 Thread Rich Nute
For a history and discussion of this symbol, see: http://www.triodyne.com/SAFETY~1/sb_v17n2.pdf Best regards, Rich This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at:

Re: Non-Compliant Products

2003-04-01 Thread Rich Nute
Hi Enci: Only this morning have I just tested a competitive product from a manufacturer in Germany, which failed miserably (+40dB) on conducted emissions testing and earth leakage, to be fair only 2mA, but the standard clearly states 1mA!. What standard specifies 1 mA? The

Re: Non-Compliant Products

2003-04-01 Thread Rich Nute
Hi Enci: How about as a consumer, buying a PC, then 6 months later (with no modifications) finds it is non-compliant (highly likeyl!!).. Can the consumer return it/demand correction/!?!? The consumer can always attempt to return a product or demand correction of a non-compliant

Administrative message: allegations of non-compliance

2003-03-31 Thread Rich Nute
The recent string with the subject OK, what's going on? alleges that a named manufacturer's product does not comply with a requirement. We feel that, in the case of a negative or derogatory comment or allegation (in this case non-compliance), the manufacturer (or individual) should NOT be

Re: product safety audit scenario

2003-02-18 Thread Rich Nute
Hi Gary: Your comment triggers another comment: Leadership. Typically, we tend to let the inspector be the leader for the duration of the inspection. The host can be the leader. The host can set the agenda (in advance, although the inspector need not be notified). First, is to decide

Re: Measuring Power Supply Output Current

2003-02-17 Thread Rich Nute
Hi Rick: On the surface it seemed like a simple exercise of putting a DC current meter in series with each of the outputs. Given that the current demand for each of these outputs is dynamic, corresponding with the processing activity, does it make sense to measure this output

Re: product safety audit scenario

2003-02-17 Thread Rich Nute
Hi Alice: Scenario : Component A with rating mentioned in the UL's product report as 90-135/180-265 Vac, however in the phyical unit is written as 115/230 V . Q1 : Is this a non conformity ? Should a VN be raised ? Yes, this is a non-conformity. In this case, the report should be

Re: North American Production-Line Tests; ANSI or Other

2003-02-13 Thread Rich Nute
Hi Peter: I am trying to find the rationale why production-line ratyhing tests in North America are usually done with a simple ohmmeter and without passing a current of say 25 A through the circuit. There must be some rationale of doing it this way somewhere. I can't answer that

Re: North American Production-Line Tests; ANSI or Other

2003-02-13 Thread Rich Nute
Hi Peter: Anyone knows of ANSI or other North American production-line test procedures/requirements for electrical/electronic equipment? Some UL and CSA standards specify the procedures for roduction-line tests, but what I am looking for is the source of these procedures/requirements.

Defamation

2003-02-13 Thread Rich Nute
A message was posted that defamed another subscriber. That subscriber has been un-subscribed and notified as to the reason. Richard Nute Administrator, IEEE emc-pstc listserver This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list.

Violation of IEEE emc-pstc advertising rule

2003-02-12 Thread Rich Nute
A message was posted by the EMC Compliance Management Group that was a blatant violation of our rules against advertising. The subscriber has been un-subscribed and notified as to the reason. Richard Nute Administrator, IEEE emc-pstc listserver This message is from the IEEE EMC

Re: EN60950 protective conductor test (was Re: Circuit Breaker Tripping Dring Fault Tests)

2003-02-06 Thread Rich Nute
Hi Peter: My comments were based on the proposed requirement to test the PE path with the circuit prospective current transient, e.g. 200 amps from a 10,000-amp source for the period of time required to operate the overcurrent device -- say less than a second or so. (The 200 amps is a

Re: Unity power factor

2003-02-05 Thread Rich Nute
Hi Neil: All I get on visiting the site is 404 Page not found error on their home page. Access to all other pages seems to be ok. Using their search engine facility does not seem to find anything with respect to application notes or harmonics. Anyone else have this problem?

Re: EN60950 protective conductor test (was Re: Circuit Breaker Tripping Dring Fault Tests)

2003-02-05 Thread Rich Nute
Hi Peter: Not quite. I^2┬Ět will tell you the let through current of the copper trace, but will not necessarily tell you if the construction will be compliant. The compliance criteria for this test include: * no damage to the trace (no lifting, probably no

Re: EN60950 protective conductor test (was Re: Circuit Breaker Tripping Dring Fault Tests)

2003-02-05 Thread Rich Nute
Hi Chris: It seems funny to me that most equipment has been historically made with 18AWG protective ground pigtail wires; and 25A ground fault tests have been used for years. Now that PC traces are being used for protective ground; we want to test with 200A or greater impulse

Re: EN60950 protective conductor test

2003-02-05 Thread Rich Nute
Hi John: Is it not permitted to express a personal preference on this group? I *prefer, personally*, not to use printed board traces as parts of the PEC. I'm not suggesting that should be in IEC 60950 or any other standard. Of course we express personal preferences in this

Re: EN60950 protective conductor test

2003-02-01 Thread Rich Nute
This message has been converted via the evaluation version of Transend Migrator. Use beyond the trial period specified in your Software Evaluation Agreement is prohibited. Please contact Transend Corporation at (650) 324-5370 or sales.i...@transend.com to obtain a license suitable for use in a

Re: Unity Power Factor

2003-01-31 Thread Rich Nute
Hi John: Thank you for that and the rest of the information, which could prove to be very helpful indeed. I would like to use it in my continuing efforts to defuse the arguments between the former TC74 experts in TC108 and the SC77A/WG1 people. May I say that the information came

Re: Unity Power Factor

2003-01-31 Thread Rich Nute
Hi John: Yes, delta-wye distribution transformer overheating does occur due to the circulation and dissipation of the triplen harmonics in the primary (delta) winding. Thank you for that and the rest of the information, which could prove to be very helpful indeed. I

Re: single fault conditions

2003-01-31 Thread Rich Nute
Hi John: The Bad: some FETs fail very violently, and can actually be a fire hazard and/or shock hazard in open-frame switchers; Really? There doesn't seem to be enough combustible material to cause a fire hazard, and an open-frame switcher always has to be in some sort of

Re: single fault conditions

2003-01-30 Thread Rich Nute
While s-c and o-c at device terminals do not simulate true fault conditions within components, testing must be practical. If we are to begin considering simulation of true fault conditions within components, there may be no end to the number of tests. We can easily put bounds

Re: Unity Power Factor

2003-01-30 Thread Rich Nute
Hi John: Aren't you in the USA? If so, you must have imagined the peak- flattening. I am assured by the US experts on SC77A/WG1 that this phenomenon is unknown in USA, and the only effect of IEC/EN 61000-3-2 is that it increases the prices of PCs dramatically and keeps US

Re: single fault conditions

2003-01-29 Thread Rich Nute
Hi Brian: The environment being considered is a switching power supply. The technique that safety agencies use to simulate a SFC on a power FET does not seem, IMHO, to simulate the actual failure mode of the device. To wit: when the mosfet fails short, it blows itself open; so

Re: Unity Power Factor

2003-01-29 Thread Rich Nute
Hi John: The only other problem that I know of is distribution transformer overheating. But, I believe such transformers are very much larger than 3 kVA, so 3 kVA of non-linear loads would have very little effect. I mean *concentrations* of loads, individually below 3

Re: Unity Power Factor

2003-01-29 Thread Rich Nute
Hi John: In the USA, this has largely been fixed by a change in the USA National Electrical Code. There must be quite a number of installations that are not yet upgraded. Where a problem existed, it was fixed by pulling another neutral. Are there any other problems

Re: Circuit Breaker Tripping Dring Fault Tests

2003-01-28 Thread Rich Nute
Hi Peter: For safety, it is not clear from the standards whether the main branch circuit breaker tripping during fault conditions is an acceptable result. I see no reason why this should not be acceptable. What is your view? Some third party labs find it acceptable

Re: Unity Power Factor

2003-01-28 Thread Rich Nute
Hi John: No, this is not much of an issue for the U.S. (unless your facility is actually affecting the utility); ... or frying the neutral conductors with third-harmonic current. In the USA, this has largely been fixed by a change in the USA National Electrical Code.

Listserver Administrative Notice

2003-01-24 Thread Rich Nute
Listserver Administrative Notices: 1. No attachments. --- Please do not post messages with attachments. We have a large number of subscribers on plain old telephone dial-up service. Messages with attachments take a long time to download, and the

jurisdiction, overlap, and delegation in USA rules.

2003-01-21 Thread Rich Nute
Hi John: The electrical safety legislation seems to be a bit more complicated in U.S. compared to EU. A very great deal more complicated, because the practical requirements are not centralized but delegated down though the local government chain, and in some cases

Re: NRTL in the U.S.

2003-01-15 Thread Rich Nute
Hi Gregg: I argue with some of your statements. :-) Dave's question - Does this apply to in-house test equipment? Hi Dave - Good question (Please see attached). I'm sorry about the file size but I took it from the Department of Labor web site several years ago when this

Re: NRTL in the U.S.

2003-01-15 Thread Rich Nute
Hi Gary: Rich Nute (I think) wrote and excellent article or e-mail on this not too long ago and should be in the archives. Its pretty concise and clear but goes into some pretty good specifics and the state laws and how they very and you will find it very helpful. Unfortunately

Re: NRTL in the U.S.

2003-01-14 Thread Rich Nute
Hi Dave: Does this apply to in-house test equipment? That is, equipment that is built in-house and remains on site? In the past I have designed in-house equipment to meet the safety standards but did not send the equipment out for testing and certification. Yes. If you check

Re: NRTL in the U.S.

2003-01-14 Thread Rich Nute
Hi Joe: As has been discussed in previous threads, NRTL Listing is not a requirement to sell electronic products in the U.S. However, there are cities, counties, etc. within the U.S. that do require NRTL Listing. These include Los Angeles and Chicago. Does anyone have a

Re: Alternatives to Brominated Fire Retardants

2003-01-14 Thread Rich Nute
Hi Richard: Does anyone know of web sites or other sources that describe feasible alternatives to bominated fire retardants in plastics? There are a number of alternatives to brominated fire retardants: Phosphorus Mineral Phosphorus is probably the most-used. There are some

Re: strange symbols (to me anyway)

2003-01-03 Thread Rich Nute
Hi Gary: As a result of searching for my copy of the indoor use only symbol, I discovered that I have a reference to the standard where the symbol is published: DIN 30 600 Reg. No. 02808-3 If one of our subscribers has a copy of this standard, perhaps he could verify the reference.

Re: strange symbols (to me anyway)

2003-01-03 Thread Rich Nute
Hi John: It is not an ISO or IEC symbol. It is either in IEC60417 already or will be in the future. It is not currently in IEC 60417. (I have no visibility as to future adoption of this symbol into IEC 60417.) Since one of our members could not decipher the symbol, I question

comment worth a further look

2003-01-02 Thread Rich Nute
Hi Luke: This won't work. If you want to look at how badly online forums work, look at the IEE website. Unfortunately, this requires a membership and a login. I really would like to know more about the success of web-based forums. Best regards, Rich

The listserver WILL continue.

2003-01-02 Thread Rich Nute
Thank you for all the comments on the listserver- based service versus the web-based service. The IEEE listserver WILL continue. I apologize for not being clear on this point. We started with listserver service. However, the listserver does not satisfy all of the needs of our

Re: Death of the listserver

2003-01-02 Thread Rich Nute
Hi Jim: Thanks for your message. The EMC Laboratory that I work for (Acme Testing Company in Acme, Washington) has the quietest open-field Emissions Sites (OATS) within a 1000 mile radius. We planned it that way. The village of Acme has a total population of under 100 people.

Re: Leakage current test conundrum

2002-12-05 Thread Rich Nute
Hi Charles: a) Does anyone one know the genesis of the requirement to lift the Neutral AND the Ground simultaneously during a leakage current test?? (I am referring to UL6500) While I am not familiar with UL 6500 per se, I believe I can comment on the lift of the neutral.

Methenamine timed burning tablet

2002-12-05 Thread Rich Nute
Some fire tests use a methenamine timed burning tablet. This tablet is specified in USA government standards for furniture flammablity testing. (See 16 CFR Part 1630.4 or CPSC standard FF 1-70.) It is also specified in ASTM D2859. I have also seen it used to test fire enclosures in

Administrative message -- posting formats

2002-11-11 Thread Rich Nute
Regarding postings, here is a re-statement of our guidelines that were sent to you when you subscribed: 1. No attachments (because many of our subscribers use dial-up modems for which message size determines the download time). If an attachment is appropriate or necessary to

docopocoss

2002-11-05 Thread Rich Nute
docopocoss This word was unknown to me. I checked an American dictionary and could not find it. Then, I called up the Google search engine and entered the word, hoping to find an English dictionary. Google immediately came back with the definition. Rich

Re: Value of Using Non-NRTL Engineering Firms?

2002-10-29 Thread Rich Nute
Hi Chris: OSHA rules apply to employers. OSHA electrical rules require employers (1) to use only electrical products that have been certified by an NRTL, or (2) in the case of custom products, to test the product in place. If you sell a non-NRTL-certified custom product to an employer

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