Shielded Cables
We recently received some shieled PS-2 cables from a vendor. Upon inspection of the cables I saw that the shield was not soldered positively to the shell, it was just twisted back, I guess in hope that the wire would make contact. When we returned these to the vendor they said you never asked for that. We'll gladly do it for an extra charge. Huh? Am I in another world here? I assumed that all shielded cables were positively connected to the shell, at least all the ones I have seen. Has anyone else encountered this? How prevalent is this in others experience? Darrell Locke Advanced Input Devices --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
FW: Correlating sine sweep with random vibration
-- From: Paul Paroff To: Darrell Locke Subject: RE: Correlating sine sweep with random vibration List-Post: emc-pstc@listserv.ieee.org Date: Friday, January 21, 2000 9:22AM To add my voice to the many, there is no agreed upon correlation between sine sweep and random vibration. A paper written by Phil Rogers of Unholtz-Dickie Corp. and Shams Jawaid of Quantum Corp. to be presented at next week's RAMS conference may shed some light on the difference. The authors measured Grms vs time in miliseconds while the pneumatic table (as found in HALT chambers) was set to 1 G. The graph shows that to achieve a time averaged value of 1 G the table is exposed to up to 50 G spikes at approximately 30 ms intervals. So there doesn't seem to be the true equivalent of a sine sweep. I do agree with your opinion that if something can survive at 60 G on a random vibe table it should pass a 1 G sine sweep. However, you may have to go to an outside lab to satisfy your customer's requirement. Or, if budget is an issue, I bet you could swap some HALT chamber time for some ED shaker time with a neighboring company. Paul Paroff Reliability Engineer Advanced Input Devices -- From: Darrell Locke To: Paul Paroff Subject: FW: Correlating sine sweep with random vibration List-Post: emc-pstc@listserv.ieee.org Date: Thursday, January 20, 2000 2:59PM Any thoughts for Doug? DL -- From: POWELL, DOUG To: EMC-PSTC (E-mail) Subject: Correlating sine sweep with random vibration List-Post: emc-pstc@listserv.ieee.org Date: Thursday, January 20, 2000 2:11PM Hello all, As a part of the safety testing of our products we have a requirements for a vibration test. EN50178 (originally DIN VDE 0160) has a 1G sine sweep test that forces us to go to a nearby environmental test lab. Where we can find a voice-coil vibration table. The cost for one large one of these is prohibitive for my company. My question: Is it possible to correlate the sine sweep with random vibration and show compliance to the standard? A more economical solution for us would be to use one of several HALT/HASS chambers we have in-house. Intuitively, it seems that testing products at 60 G's or more, over a wide spectrum, should exceed the 1G sinusoid. But so far, everyone I know indicates there is no way to do this. By the way, I do understand some things about the dwell time and resonance's. Still I would like to hear your inputs on this... -doug == Douglas E. Powell Regulatory Compliance Engineer Advanced Energy Industries, Inc. mailto:doug.pow...@aei.com http://www.advanced-energy.com == - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: ESD on USB devices
I'm in the process of buying a Dell for USB EMC testing. I'll let you know how it does. This potenially be a major problem so any input from the group on success with USB would really help. Virtually all computers now have USB ports and USB peripherals are becoming more available. Darrell Locke Advanced Input Devices -- From: Jennifer Holmes To: emc-p...@majordomo.ieee.org Subject: ESD on USB devices List-Post: emc-pstc@listserv.ieee.org Date: Thursday, January 20, 2000 10:01AM We are CE testing a USB device and having problems getting it to pass ESD due to the host PC locking up. We have tested several competing products that are similar in design which are all CE marked. Our device seems to be more immune to contact discharges than theirs, which stop working even when you shock the ground plan next to the deivce. This leads us to believe that it is our test setup rather than our deivce which is causing the problem. So far we have tried it with two Gateway towers and a Gateway laptop, all with universal host controllers. We have gotten the same results on all three. Has anyone had any success ESD testing USB products? Thanks, Jennifer Holmes - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: safety ground wire
I have in the past worked on a UPS project where we provided double insulation from all hazardous voltages to the operator interface, and a three pronged line cord with the green wire ground bonded to the chassis. In essence we had both types of protection which we thought was good. However, we received some confilcting views on this, especially concerning Europe. Some people said we could not have both. I do not remember the reasoning why. Is there anything prohibiting simultaneous protection schemes? Darrell Locke Advanced Input Devices -- From: Rich Nute To: ken.ja...@emccompliance.com Cc: emc-p...@majordomo.ieee.org Subject: Re: safety ground wire List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, December 01, 1999 9:19AM Hi Ken: Thank you for your comprehensive answer. I am a little surprised that after all the discussion in this forum on specs relative to the width of the yellow stripe on the green wire that there is no rule on how or if things get a green wire in the first place! The choice of whether to design any particular product as double-insulated or grounded is the manufacturer's choice. The rules are: If your product is grounded, it shall meet these requirements... If your product is double-insulated, it shall meet these requirements... We, HP, make both double-insulated and grounded computer peripheral products. We waffle back and forth between the two constructions, and are not consistent in our choice. Our primary motivation is cost. Two-wire seems to be lower cost (one less wire, etc.). But, the EMC filter seems more difficult to design. Then, we are concerned with worldwide distribution. The same two-wire plug can be used in many more countries than the grounded plug (i.e., Denmark, Switzerland, Italy). So, there are fewer power cords to stock. But, we already stock all of the grounded power cords. Finally, there is customer convenience. Two-wire works everywhere, grounded only works in a grounded environment. Japan residences are 2-wire. Many European residences have both grounded and 2-wire outlets in various parts of the home. Many homes in North America still have 2-wire outlets. So, there seems to be some advantages to 2-wire. On the other hand, grounded is a very familiar construction, and is easy and straight-forward for both design and manufacturing. No rule. Manufacturer's choice, but biased by competition and inertia of the product line. Vacuum cleaners are 2-wire; washers are grounded. Best regards, Rich ps: Yes, we do get hung up on issues such as the width of the stripe on the grounding conductor because this is a RULE. The choice of using a grounding conductor is NOT a rule. The only rule is that the product must be either grounded or double-insulated. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: WEEE Directive
One problem is with retractile type jacketed cables (used for coiled cables). PVC just doesn't work. These are usually polyurethane, which have traditionally used halogen-based flame retardants. There are some non-halogenated compounds available. BF Goodrich for instance, produces a product called ESTANE that has a non-halogen flame retardant. You should specify the jacket material on the cable drawing or you will likely get a halogen flame retardant for polyurethane cables. Darrell Locke Advanced Input Devices -- From: Rich Nute To: wo...@sensormatic.com Cc: emc-p...@majordomo.ieee.org Subject: Re: WEEE Directive List-Post: emc-pstc@listserv.ieee.org Date: Tuesday, November 09, 1999 8:03AM Hi Richard: Are there currently any alternative wire and cable constructions that comply with UL and NEC flame requirements without the use of halogenated flame retardants? I believe PVCs are naturally flame-retardant materials i.e., have no flame retardants added to them. Many commonly-used wire and cable insulations are PVC. Best regards, Rich - Richard Nute Product Safety Engineer Hewlett-Packard Company Product Regulations Group AiO Division Tel : +1 858 655 3329 16399 West Bernardo Drive FAX : +1 858 655 4979 San Diego, California 92127 e-mail: ri...@sdd.hp.com - - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Conductive Coating
In my experience with these coatings the choice of material for EMI puposes doesn't matter that much. Nickel or copper work just fine. I have seen 30db attenuation based on the coating alone. The are some other problems with safety/reliability, and material selection is important. Select compatible coatings and plastics as listed in the UL Plastics Recognized Ccomponent Directory Select an application vendor and test incoming samples with the ASTM 3359 Tape Adhesion Test. We have found compatible materials that fail this test due to improper application. The coating doesn't always adhere to the substrate well. Poorly applied or incompatible materials can cause problems by flaking over time, or with abrasion, thereby sprinkling your PCBs with conductive dust. Recyclability is becoming an issue in Europe which should give copper an advantage. Darrell Locke Advanced Input Devices -- From: George Tang To: Westerdahl, Eric Cc: 'EMI-PS Group' Subject: Re: Conductive Coating List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, November 03, 1999 6:24PM There are many different types of conductive coatings available. Silver paint is very conductive, less than 5 ohms per square inch. But it is not as scratch resistant as sheet metal surfaces. Electroless copper / nickel plating is very conductive and durable. You can get as low as 1 ohm per square inch. If you don't, your plating is not thick enough. This plating should pass the safety fault current test, as long as the safety ground wire makes surface area contact with the plating and not point contact. This plating has 60 dB shielding effectiveness for frequencies above 30 MHz, since it is much thicker than the skin depth. You need the thickness for the safety fault current. The best feature of the plating is that it allows you to mold your chassis into one piece of plastic with no extra metal pieces to assemble. It's kinda nice that way. :-) go to www.ccoatings.com or call (972) 851-0460 George Tang Westerdahl, Eric wrote: Our company has decided to use a conductive coating to mitigate some EMI problems on one of our units. We have not used this method before. I have a question as to the correct resistivity of the coating. What range should I be looking at, and does the range change if the frequency of the strong signal are high or low? The equipment is IEC 950 and EMC Directive stuff with many noisy DC motor and motor controller combinations. Most of the signals we are concerned about are at the lower end of the CISPR 22 region. 30 to 150 MHz. Eric Westerdahl Regulatory Engineer Roll Systems, Inc. eric_westerd...@rollsys.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: PBBs (Polybrominated Biphenyls), and PBDEs (polybrominated d iphe nyl ethers).
Yes, these are used as flame retardants in some plastics. Check with the resin manufacturers, they should know about it. GE Plastics for instance, has published a document stating which plastics have the PBBs. Darrell Locke Advanced Input Devices -- From: Crane, Lauren To: s...@world.std.com; emc-p...@ieee.org Subject: PBBs (Polybrominated Biphenyls), and PBDEs (polybrominated diphe nyl ethers). List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, November 03, 1999 8:56AM The European Commission is contemplating a directive (the WEEE directive) that, in its current draft, will require a phase out of the use of some substances typically found in electronic devices, including PBBs (Polybrominated Biphenyls), and PBDEs (polybrominated diphenyl ethers). I wonder if these chemicals are the ones typically used to provide printed circuit boards with their flame retardant qualities (i.e. UL 94-V0 rating). Does anyone out there know? Best Regards, Lauren Crane Eaton Corporation. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Plastics ratings
When you say sheet form, I assume you mean thin materials like .020-.040 inch. You probably will not find any materials that are rated for the 94-5VA test. There are some thin materials like the GE Lexan FR grade, or Bayer Makrofol EPC that have 94V-0 ratings and may pass your test. Keep in mind you must pass an impact test as well. You may want to use a molded, thin panel in a greater thickness. There are plenty of materials for this that come in clear such as polycarbonates (GE Lexan, Bayer Makrofol) of ABS/PC blends (Bayer Bayblend) that come in clear. The RCD lists these in pellet form. Darrell Locke Advanced Input Devices -- From: sparaci...@andovercontrols.com To: emc-p...@ieee.org Subject: Plastics ratings List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, October 06, 1999 8:22AM Hello All, I'm looking for a plastic material that can be used as a window on a fire enclosure door. This material must be available in sheet form, be able to withstand impact and be rated 94-5VA. I referenced the (1996) UL plastics R/C directory and found nada. I know, I need to buy the 1999 issue.. Anyway, if anyone knows were I can get something like this please let me know. Also any insight on other materials ie. tempered or reinforced glass etc. would be welcome. Thanks, George - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
MOV's vs Unipolar Suppressors
Compliance Collegues, I have a question on MOV's (bi-polar) vs Transorbs (unipolar) devices for board level transient protection, specifically ESD pulses that are very fast rising. The MOV type devices are inexpensive and come in arrays, so theyr'e pretty easy to use. I have heard arguments against these type of devices because a negative going pulse can drive an IC pin below ground (greater than a diode drop) and cause the IC to be damaged by sourcing a large current. Some engineers prefer a unipolar device for this purpose. I have not however, seen this to occur in the test lab. Has anyone experimented or have opinions on this? Thanks Darrell Locke - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: That doesn't make any sense
A few years back with another company I was in one of these situations. Soon after the EMC Directive went into effect, I spent days at the direction of a manager trying to provide proof that our product legally only needed to meet Class A for Europe. In the end, none of this mattered, because the end customer (large telecom company) insisted on Class B and would accept nothing else. I have since found that regulatory issues are almost always customer issues. Managers and business people understand this. No one wants to be selling a product that doesn't meet all the applicable safety or EMC requirements. Competitors would have a heyday with it. Darrell Locke -- From: Schanker, Jack To: ri...@sdd.hp.com Cc: emc-p...@ieee.org Subject: That doesn't make any sense List-Post: emc-pstc@listserv.ieee.org Date: Friday, July 30, 1999 6:36AM Rich: I want to thank you, and compliment you, for so accurately describing managment reactions to regulatory problems in your July 20 posting to the emc-pstc. It completely mirrors my own past (and continuing) experiences. I have also gotten the reaction well, that doesn't make any sense in relation to an inconvenient rule in some international standard. Why did they do that ? is asked, like I should know. Then the big question: Can we get a waiver? Dialogue: No, I don't think so. Manager: Did you try? The years of experience and intuitive feel for what is and what is not possible, mean little to the uninformed arrogance of a manager who is used to having it his way (almost always his) and expecting the world to turn at his command. The bad news aspect also looms large, as you so aptly describe. Gotta get back to work. Jack Jacob Z. Schanker, P.E. Director of Agency Compliance Adaptive Broadband Corporation 175 Science Parkway Rochester, NY 14620 USA +716 242 8454 (voice) +716 241 5590 (fax) jschan...@adaptivebroadband.com The opinions expressed above are obviously someone else's. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Operator Interface Displays
Typically the default is the light industrial immunity standard EN50082-1 which calls out IEC 1000-4-2 for ESD. Levels can be up to 15kV. Air discharge is used on insulating surfaces such the keyboard, and contact of metal surfaces. In my expereince most testing is done with the air discharge tip. The indirect testing can be troublesome too, especially with cables. We usually test to the highest level 15kV. Particular standards such as medical may change this. Darrell Locke Advanced Input Devices -- From: Biggs, Daniel (IndSys, GEFanuc, NA) To: 'EMC forum' Subject: Operator Interface Displays List-Post: emc-pstc@listserv.ieee.org Date: Friday, July 30, 1999 7:01AM Does anyone know of a standard that talks about the testing requirements on a display/keyboard interface. I am interested in knowing what kind of ESD tests to perform on it. Are contact, air and indirect discharge necessary? Does anyone have experience with Operator Interfaces? Are there particular levels that they have to meet? DB ___ Daniel W. Biggs Test Engineer HW Development Process Engineering Services daniel.bi...@cho.ge.com GE Fanuc Automation PO Box 8106 Charlottesville, VA 22906 PH: (804) 978-6946 Fax: (804) 978-5588 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
EU Authorized Representative
Hello Members, What are manufacturers doing about listing an authorized representative in the Declaration of Conformity for the EU when they have no European Sales office or distributor? Are there import specialists and attorneys in the EU for this purpose? Thanks in advance Darrell Locke Advanced Input Devices - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Clean Room Compatible
Dear Members, Does anyone know of standards(i.e. SEMI) for products classified as Clean Room Compatible. I'm assuming it covers plastics outgassing and things like that. Thanks in advance Darrell Locke Advanced Input Devices - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Plastics Cert Documentation
Dear Fellow Members, We have a plethora of plastic subassemblies, produced by outside vendors, that are received and stocked in our factory. We must keep certs of flammability on file for each shipment of every plastic part to satisfy UL, CSA, and TUV factory inspectors. This involves sorting and filing lots of paper and maintaing a long row of filing cabinets. The method seems cumbersome in this electronic age. Does anyone have experience with easier methods of tracking these certs that is also acceptable to the agencies. Thanks very much Darrell Locke Advanced Input Devices - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: water-cooled electrodes
Jeff, Items 2 and 4 are probably correct. It is a very specialized subject that most compliance people do not deal with. You have a list of 10 questions that are quite general like are water fittings inherently unsafe?. These probably require detailed answers that take some research. Most questions posed on the EMC-PSTC are single, very specific questions, and those individuals with specific expertise can answer them in a couple paragraphs. Darrell Locke Advanced Input Devices -- From: JENKINS, JEFF To: JENKINS, JEFF; 'emc-pstc' Subject: RE: water-cooled electrodes List-Post: emc-pstc@listserv.ieee.org Date: Friday, November 13, 1998 10:26AM Hi all, I have received no responses to the original e-mail copied below. This in itself is rather interesting and I would like to know why, so if any of you have opinions on this, I'd like to hear them. My assumption is that there have been no responses for one or more of the following reasons: (1) Such knowledge is considered a market advantage and is proprietary; (2) No one in the group has knowledge pertaining to this subject; (3) People are queasy about the subject; (4) The query was lengthy and people did not have the time to respond (quite understandable); (5) The query was unclear; (6) For some mysterious reason, the e-mail didn't reach anyone in the group but me and my colleague at Advanced Energy. Anybody want to take a stab at this? Regards, Jeff Jenkins Senior Regulatory Compliance Engineer Advanced Energy Industries, Inc. Fort Collins, CO USA 80525 Opinions are my own and not necessarily shared by Advanced Energy Industries, Inc. or its affiliates. -Original Message- From: JENKINS, JEFF Sent: Wednesday, November 04, 1998 2:07 PM To: 'emc-pstc' Subject: water-cooled electrodes I would like to know if anyone in the group has been involved with the AGENCY APPROVAL of a product containing a water-cooled live electrode or coil, and what had to be done to make this safe in the eyes of the agency. My company is occasionally involved with this sort of thing, and some feel that we are being overly conservative and perhaps unnecessarily burdening our products with extra cost. To date we have only CE-marked such products and have had no third-party involvement. Partial list of concerns: (1) Is it considered necessary to completely isolate the water-cooled live component from circuitry by locating it in a separate chamber? (2) Single-fault safety when circuitry is in the same enclosure as the coil -- if the tube ruptures and the box fills up with water, this is a hazard as water is rightly considered a conductive element. Drains are sometimes used to avoid this, but there is still the problem of water spraying. Splash guards and the like may be used but this involves some expense. Is copper tubing considered inherently unsafe, i.e. something that is expected to rupture? (3) If we use de-ionized water (and stainless steel tubing to avoid the copper corrosion problem), can we assume the water acts as a protective impedance? Could we prove this by filling the chamber with de-ionized water, applying RF, and measuring the leakage current? How much RF leakage current is permissible? (4) Are water fittings considered inherently unsafe? We have been unable to find any agency-approved fittings. (5) Has anyone considered (or accepted) putting a ferrite around the water tubing to form an inductor, thus limiting the RF current in the water? Or coiling the tubing to create an air-core inductor? (6) I once received an RF burn from an experimental system with a water-cooled cathode. This was in a crude garage shop atmosphere (not our company). The cathode was immersed in water that was sourced from a faucet, so it was ordinary tap water. The supply was 400kHz, 5kW. The water supply hose was ordinary garden hose. Between the faucet and the cathode were two lengths of garden hose with brass fittings. I inadvertently touched the fitting that connected the two hoses together, about ten feet from the cathode. The only grounding at the time was whatever was achieved at the faucet. We later provided some grounding at the fittings and supplementary grounding at the faucet. All this prompts the question: Is it considered sufficient protection if the bulkhead fittings are fitted to a grounded enclosure? Are starwashers or the like required? (7) Is it necessary to provide a SUPPLEMENTARY ground for the enclosure containing the water-cooled coil/electrode? (8) What if, instead of running water THROUGH the coil, the entire coil is IMMERSEDin water in a metal enclosure? Would double ground connections be sufficient, assuming the leakage current is within allowable limits? (9) Is it allowable to connect neoprene hose to the coil? I have some doubts about neoprene's capacity to withstand RF fields. What hose materials would be considered safe/reliable? (10) Is a drain required? If so, must it be large enough to drain
DS-2
Dear Fellow Members, We have a Mil-Spec requirement on one of our products that requires chemical resistance to DS-2. Does anyone know what DS-2 is? Thanks Darrell Locke Advanced Input Devices - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Power Switcher IC
We have a new display panel design that requires a a small switcher for power. The end product must meet Class B emissions. We are planning on using the Linear Technology LT1376 IC which contains the control circuitry and switch. It operates at 500KHz and is rated at 1.25 amps. Has anyone had any specific problems or horror stories using this part with respect to emissions. Thanks very much Darrell Locke Advanced Input Devices - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: FDA Requirements
Mike, I posed this question to the group a few weeks back. See the archive postings for July 28 and 29 for responses. I also did research and could not come up with any written requirements for stainless steel. It seems to just be a commonly accepted practice. Darrell Locke Advanced Input Devices -- From: Mike Morrow To: IEEE EMC Board Subject: FDA Requirements List-Post: emc-pstc@listserv.ieee.org Date: Thursday, August 27, 1998 6:03AM I've always been told that any piece of equipment being used in a sanitary application (i.e. food processing, etc) must be constructed of stainless steel. I'm after the actual standard that has this requirement. Can aluminum be used?? Any help is appreciated. Mike Morrow Product Standards Engineer Data Instruments mike_mor...@datainstruments.com mmor...@compuserve.com Phone 978-264-9550 xt-201 Fax 978-263-0630 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators).
ESD Lab Certification
Dear Members, We would like to get our ESD Lab Certified for doing testing to IEC 1000-4-2. Does anyone know which standards are to be used for lab layout, grounding, and procedures to be followed. What bodies or agencies can certify a lab? Thanks Darrell Locke Advanced Input Devices
Quiet Monitor Responses
RCIC Group Members, Thanks for all the responses on my request for a Quiet Monitor. Several people echoed my problems with emissions and monitors. The following monitors were recommended: Nokia 445Xi WEN Technology Corp Model JK1461, model JD178A, (Shirasuna Electric Corp) HP HP D2817A (17 inch) HP Ergo Super VGA Monitor, Model number D1195A Sony Trinitron, MultiScan 100 SX NEC Multisync IBM P70 IBM P201 ELO TouchSystems (No Model designated) I have heard that the new flat LCD Monitors are good too, although pricey ($1700-2200). A couple respondents said they had problems specifically with the monitor cables rather than a particular brand or model of monitor. Darrell Locke Advanced Input Devices
IEC Spray Nozzle
Can anyone tell where where I can find a reasonably priced IEC Spray Nozzle as specified in figure 5 of IEC 529? Thanks in advance Darrell Locke Advanced Input Devices
RE: Power Outages
Tom I used to work for a telecom UPS company and we used data on lighting that I think was compilied from the National Weather Service. We used this data because there was such a strong correlation between lightning activity and incidence of power outages. Florida was definitely the highest in the US. As far as length of outages this seemed to vary greatly and you could probably get information from utility companies. I remember one customer we had in the Philipines shut the grid down for 6 hours every day! Intimately related to backup time is recharge time. If you have lots of storm activity over several days you will not achieve your backup time with less than fully charged batteries. Darrell Locke Advanced Input Devices -- From: Tom Brose To: 'EMC-PSTC Email Forum' Subject: Power Outages List-Post: emc-pstc@listserv.ieee.org Date: Tuesday, August 12, 1997 6:41AM I am trying to decide how much backup battery capacity I should have in a particular product for the home environment. The only purpose of the battery is to allow product operation during the more common (hopefully short) power outages. Could anyone point me in the direction of data about the frequency and duration of utility power outages? The areas I am most interested in are North and South America and Europe. Thanks. Tom Brose tbr...@aksys.com
RE: CD ROM's
Richard, It is my understanding that the FDA requires any product incorporating a laser to be registered with the CDRH. I have a similar situation with a remote we manufacture that incoporates a laser as a pointing device. Even though our supplier has the laser registered, we must still register the end product that utilizes the laser. It is largely a paperwork job, but we must test the device for proper output level and insure the labling and warnings are correct. CD ROM's in a computer may be different. There is a good article on laser requirements in Compliance Engineering May-June 1996 Darrell Locke Advanced Input Devices -- From: richard.pa...@bangate1.tek.com To: emc-p...@ieee.org Subject: CD ROM's List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, July 23, 1997 8:43AM Good Day All: I have a question. Perhaps this is not quite the right forum, but I am hoping that if no one here has the answer that at least you may be able to point me in the right direction. In the U.S. there are FDA requirements for Laser products. If I take a CD ROM drive that I have procured from a reputable manufacturer and which that manufactrurer has properly registered with the FDA (and which bears the appropriate markings) and I install this INTERNALLY into my computer product, what are the reporting and labeling requirements for the end product, my computer ? Is my computer now a Laser product, or is the CD ROM drive the Laser product ? I am assuming here that the Laser in the CD ROM is Class I (I hope and believe that this is typically the case). If my end product is not a computer, but rather a piece of Test and Measuring Equipment does that change anything ? What about the rest of the world ? If I comply with IEC825/EN60825, are there any other countries where there are additional reporting and labeling (or other) requirements ? Your comments will be very much appreciated. Richard Payne Tektronix, Inc. richard.pa...@tek.com
