RE: Why routine hipot is required.
Hi Mike, If I understand well the computer power supply has a IEC 730 power supply input and the mounting in a computer frame would not alter the way the supply is connected to the mains. (plug-in directly in the supply through a enclosure hole). Then the computer does not need HiPot testing unless you do not have 101 % confidence in the power supply manufacturer, and are ready to bear responsibility for your power supply manuf. mistakes Worded differently: You are legal responsible for any safety failure with your product. In case of an accident , it's your boss to sue the supply manufacturer... and to recover any damage done to your companies name and reputation. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf >>Of Mike Morrow >>Sent: Thursday, August 31, 2000 7:40 PM >>To: EMC Society >>Subject: Why routine hipot is required. >> >> >> >>I've been asked why a routine hipot test is required on an end assembly >>computer when it uses a Listed power supply that has already been hipot >>tested. So far I don't like the way I've worded my response. Basically >>what I've said is that a power supply is approved as a component. The end >>safety of the device depends on the installation. >> >>Can anyone add some more beef to this statement. Thanks. >> >>Mike Morrow >>Senior Compliance Engineer >>Ucentric Systems >>978-897-6482 >>mi...@ucentric.com >>www.ucentric.com >> >> >>--- >>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 >> >> >> <>
RE: Why routine hipot is required.
> -Original Message- > From: Mike Morrow [mailto:mi...@ucentric.com] > Sent: Thursday, August 31, 2000 10:40 AM > To: EMC Society > Subject: Why routine hipot is required. > > > > I've been asked why a routine hipot test is required on an > end assembly > computer when it uses a Listed power supply that has already > been hipot > tested. So far I don't like the way I've worded my response. > Basically > what I've said is that a power supply is approved as a > component. The end > safety of the device depends on the installation. > > Can anyone add some more beef to this statement. Thanks. > > Mike Morrow > Senior Compliance Engineer > Ucentric Systems > 978-897-6482 > mi...@ucentric.com > www.ucentric.com > So how about adding: During the manufacturing process, we assemble a collection of approved components into a finished product. There is a possibility that one of our operations may damage or degrade one of these approved components. Further, these approved components are connected with materials added by us during the manufacturing process. Any of these materials may be mis-applied or damaged during the process, also degrading the performance of our finished product. In order to ensure the safety of our product, we must perform a final high-voltage integrity test. A little beef, a little chicken, and a schmear of lox. Ed :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-) Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-) --- 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
RE: Why routine hipot is required.
Mike, I have in the past had UL/CSA hi-pot testing waived for the production line testing of the end product based on the specific method of installation of the power supply in the end product. Bandele Jetstream Communications, Inc. badep...@jetstream.com -Original Message- From: Mike Morrow [mailto:mi...@ucentric.com] Sent: Thursday, August 31, 2000 10:40 AM To: EMC Society Subject: Why routine hipot is required. I've been asked why a routine hipot test is required on an end assembly computer when it uses a Listed power supply that has already been hipot tested. So far I don't like the way I've worded my response. Basically what I've said is that a power supply is approved as a component. The end safety of the device depends on the installation. Can anyone add some more beef to this statement. Thanks. Mike Morrow Senior Compliance Engineer Ucentric Systems 978-897-6482 mi...@ucentric.com www.ucentric.com --- 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 --- 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
RE: Why routine hipot is required.
Mike, In my experience, the purpose of the end-assembly, 100% mfg. hi-pot test is to check the integrity of the electrical connections and of the required isolation levels. On the manufacturing end, any number of events can create a disturbance in the insulation of the product. These can often include insulation migration, miswiring, skinned insulation on conductors, quality issues with OEM supplied parts (i.e. connectors, supplies, etc.) due to time or transportation effects and so onthink Murphy's Law. Restated, the factory test will help identify an otherwise catastrophic fault waiting to happen out in the field. For the most part, it's effective and pretty much required by a safety agency as part of the approval. Cheers, Kaz Gawrzyjal Sr. Product Safety Engineer -- Sanmina Canada ULC Wireless Development Centre 2924 11 Street NE Calgary, Alberta Canada, T2E 7L7 tel:403-232-4805 (ESN 765) fax:403-232-4813 (ESN 765) e-mail: k...@nortelnetworks.com > -Original Message- From: Mike Morrow [mailto:mi...@ucentric.com] Sent: Thursday, August 31, 2000 11:40 AM To: EMC Society Subject: Why routine hipot is required. I've been asked why a routine hipot test is required on an end assembly computer when it uses a Listed power supply that has already been hipot tested. So far I don't like the way I've worded my response. Basically what I've said is that a power supply is approved as a component. The end safety of the device depends on the installation. Can anyone add some more beef to this statement. Thanks. Mike Morrow Senior Compliance Engineer Ucentric Systems 978-897-6482 mi...@ucentric.com www.ucentric.com --- 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
Re: Why routine hipot is required.
Hi Mike: > I've been asked why a routine hipot test is required on an end assembly > computer when it uses a Listed power supply that has already been hipot > tested. So far I don't like the way I've worded my response. Basically > what I've said is that a power supply is approved as a component. The end > safety of the device depends on the installation. There are two answers... First, certification houses require testing of the end-product in its final configuration. This requirement is based on the idea that the end-product manufacturer can affect the primary circut insulation until the enclosure is installed. In some cases, where the power supply includes all of the primary circuit including the input connector, and is fully enclosed in its own enclosure that meets end- product specs, the certifier will waive the end-product test. Note that this waiver is based on the idea that the construction of the power supply precludes the end- product manufacturer from affecting the primary circuit insulation. Second, it is appropriate to re-test due to the effects of time and transportation on the power supply. Others have already provided anecdotes on these effects. I'll add one more: A primary wire was pinched, but passed the power supply manufacturer's hi-pot test. After crossing the ocean in a ship, the power supply failed the hi-pot test. During the crossing, the wire insulation cold-flowed until the remaining insulation was too thin to pass the hi-pot test. Best regards, Rich --- 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
Why routine hipot is required.
Mike, The global safety standards for ITE require an electric strength test per section 5.3. This applies to the entire assembly as certilisted. Section 5.3.2 describes the "type" test necessary for certification. IEC 60950, nor its counterparts, explicitly state that production hi- pot testing must be conducted, but the section does include a note that "for production test purposes" the duration of the test can be reduced to 1 sec. However, I believe that any agency, especially those with mandatory follow-up-services, will require production hi-pot testing to approve an ITE product. This is usually the most scrutinized process step for any initial factory inspection, even by China's CCIB or Poland's PCBC. Suppose an ITE product contains multiple sub-assemblies which include mains voltages or higher, e.g. power supply, fuser, CRT, etc. Suppose each is an agency recognized or listed component, and undergo a hi-pot check at their site of manufacture. Why hi-pot a product comprised of theses sub-asseblies? The reasons are many. The sub-assemblies can be damaged in shipment. During final product assembly, a nut or screw can fall into a power supply or other sub-assemly. All mains cabling and connections between the separate assemblies must be verified to pass hi-pot. Hope this helps. George -- Forwarded by George Alspaugh/Lex/Lexmark on 09/01/2000 12:10 PM --- mikem%ucentric@interlock.lexmark.com on 08/31/2000 01:40:27 PM Please respond to mikem%ucentric@interlock.lexmark.com To: emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: Why routine hipot is required. I've been asked why a routine hipot test is required on an end assembly computer when it uses a Listed power supply that has already been hipot tested. So far I don't like the way I've worded my response. Basically what I've said is that a power supply is approved as a component. The end safety of the device depends on the installation. Can anyone add some more beef to this statement. Thanks. Mike Morrow Senior Compliance Engineer Ucentric Systems 978-897-6482 mi...@ucentric.com www.ucentric.com --- 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 --- 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
RE: Why routine hipot is required.
Basically - high potential testing is a means to check the integrity (safety) of the wiring/components and construction used in the "front end" before the power supplies. I have two "free" publications, from two companies that manufacture high potential testers, that explain the process and needs very well. I checked their web sites but they were not available on the site. You may need to call them. Slaughter - 800-412-1921 - Basic Facts About High Voltage Testing Associated Research, Inc. - 1-800-858-8378 - A Basic Guide to Electrical Product Safety Testing Good Luck! -Original Message- From: Mike Morrow [mailto:mi...@ucentric.com] Sent: Thursday, August 31, 2000 12:40 PM To: EMC Society Subject: Why routine hipot is required. I've been asked why a routine hipot test is required on an end assembly computer when it uses a Listed power supply that has already been hipot tested. So far I don't like the way I've worded my response. Basically what I've said is that a power supply is approved as a component. The end safety of the device depends on the installation. Can anyone add some more beef to this statement. Thanks. Mike Morrow Senior Compliance Engineer Ucentric Systems 978-897-6482 mi...@ucentric.com www.ucentric.com --- 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 --- 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
Re: Why routine hipot is required.
Mike, I made the same mistake. The power supply was recognized. - Original Message - From: Pryor McGinnis To: Mike Morrow ; EMC Society Sent: Friday, September 01, 2000 12:31 PM Subject: Re: Why routine hipot is required. > Mike, > > Back in my days as Compliance Engineer for AT&T Global Information Solutions > (NCR), I was successful in obtaining UL/CSA waiver for production line hipot > testing of the end product on the basis of using a listed power supply that > had already been subjected to hipot as a part of the power supply > manufacturing process. Hipot was still required as a part of the UL/CSA > evaluation for initial listing of the end product. > > Ground continuity testing was still required due to the fact that the > mounting of the power supply in the end product established necessary > contacts for ground continuity. > > - Original Message - > From: Mike Morrow > To: EMC Society > Sent: Thursday, August 31, 2000 1:40 PM > Subject: Why routine hipot is required. > > > > > > I've been asked why a routine hipot test is required on an end assembly > > computer when it uses a Listed power supply that has already been hipot > > tested. So far I don't like the way I've worded my response. Basically > > what I've said is that a power supply is approved as a component. The end > > safety of the device depends on the installation. > > > > Can anyone add some more beef to this statement. Thanks. > > > > Mike Morrow > > Senior Compliance Engineer > > Ucentric Systems > > 978-897-6482 > > mi...@ucentric.com > > www.ucentric.com > > > > > > --- > > 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 > > > > > --- 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
RE: Why routine hipot is required.
Mike: Here's the beef. The hi-pot test on the completed assembly, or final product, should be done as close as possible to the point of production where the product is boxed up for shipping and/or storage. The purpose of this is to try and find a defect in the primary side of the product wiring that may have been induced as part of the assembly process, such as a cable being pinched where the insulation is now broken. Even if the component power supply you are installing in your product is Listed (most are Recognized), there may be an instance where someone on the production line had too much weekend and wired something incorrectly (such as the input to the supply). In my days of working for a computer manufacturer, I can recall a specific instance where a "listed" molded cordset had ground and line reversed on one end. What a happy surprise for the test operator that was. Bottom line is that the production hi-pot test is the last line of defense in assuring that the manufacturer is not sending out a liability inducing, honey, we just lost the farm death trap. Sincerely, Robert Loop Engineering Supervisor Wyle Laboratories Product Safety ph - (256) 837-4411 x313 fax- (256) 721-0144 e-mail: rl...@hnt.wylelabs.com __Reply Separator > -- > From: Mike Morrow[SMTP:mi...@ucentric.com] > Reply To: Mike Morrow > Sent: Thursday, August 31, 2000 12:40 PM > To: EMC Society > Subject: Why routine hipot is required. > > > I've been asked why a routine hipot test is required on an end assembly > computer when it uses a Listed power supply that has already been hipot > tested. So far I don't like the way I've worded my response. Basically > what I've said is that a power supply is approved as a component. The end > safety of the device depends on the installation. > > Can anyone add some more beef to this statement. Thanks. > > Mike Morrow > Senior Compliance Engineer > Ucentric Systems > 978-897-6482 > mi...@ucentric.com > www.ucentric.com > > > --- > 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 > > --- 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
RE: Why routine hipot is required.
Mike, I have had instances on the manufacturing line were the unit would fail the Hipot or Ground Bond test. The same holds true. The power supply is an approved part and was tested by the power supply house. With this information alone I would recommend doing the tests on the end product. Josh -Original Message- From: Mike Morrow [mailto:mi...@ucentric.com] Sent: Thursday, August 31, 2000 10:40 AM To: EMC Society Subject: Why routine hipot is required. I've been asked why a routine hipot test is required on an end assembly computer when it uses a Listed power supply that has already been hipot tested. So far I don't like the way I've worded my response. Basically what I've said is that a power supply is approved as a component. The end safety of the device depends on the installation. Can anyone add some more beef to this statement. Thanks. Mike Morrow Senior Compliance Engineer Ucentric Systems 978-897-6482 mi...@ucentric.com www.ucentric.com --- 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
RE: Why routine hipot is required.
Mike, During Hi-pot testing, in addition to punctured wiring insulation and blatant mis-wiring, I have experienced failures due to faulty/broken components recognized power supplies used inthe equipment. Therefore I am all for it . . . . John Juhasz Fiber Options Bohemia, NY -Original Message- From: Eric Petitpierre [mailto:eric.petitpie...@pulse.com] Sent: Friday, September 01, 2000 8:33 AM To: Mike Morrow Subject: Re: Why routine hipot is required. Mike, It would be an easier job to explain if the supply was Recognized rather than Listed. The best way I can think to support you arguement is to give examples. For example, I have seen ac leads get miswired. If the supply is fed through an on board IEC connector, it is hard to mess that up. Another example is the screws holding the supply in place. Suppose the usual screws are not available for whatever reason..longer screws get used instead. Those screws could compromise the isolation. Seen that happen as well.. Good luck, Eric Petitpierre eric.petitpie...@pulse.com _ _ Reply Separator _ Subject: Why routine hipot is required. Author: mi...@ucentric.com (Mike Morrow) at smtp List-Post: emc-pstc@listserv.ieee.org Date:8/31/00 1:40 PM I've been asked why a routine hipot test is required on an end assembly computer when it uses a Listed power supply that has already been hipot tested. So far I don't like the way I've worded my response. Basically what I've said is that a power supply is approved as a component. The end safety of the device depends on the installation. Can anyone add some more beef to this statement. Thanks. Mike Morrow Senior Compliance Engineer Ucentric Systems 978-897-6482 mi...@ucentric.com www.ucentric.com --- 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 --- 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
Re: Why routine hipot is required.
Mike, Back in my days as Compliance Engineer for AT&T Global Information Solutions (NCR), I was successful in obtaining UL/CSA waiver for production line hipot testing of the end product on the basis of using a listed power supply that had already been subjected to hipot as a part of the power supply manufacturing process. Hipot was still required as a part of the UL/CSA evaluation for initial listing of the end product. Ground continuity testing was still required due to the fact that the mounting of the power supply in the end product established necessary contacts for ground continuity. - Original Message - From: Mike Morrow To: EMC Society Sent: Thursday, August 31, 2000 1:40 PM Subject: Why routine hipot is required. > > I've been asked why a routine hipot test is required on an end assembly > computer when it uses a Listed power supply that has already been hipot > tested. So far I don't like the way I've worded my response. Basically > what I've said is that a power supply is approved as a component. The end > safety of the device depends on the installation. > > Can anyone add some more beef to this statement. Thanks. > > Mike Morrow > Senior Compliance Engineer > Ucentric Systems > 978-897-6482 > mi...@ucentric.com > www.ucentric.com > > > --- > 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 > > --- 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
