Re: Hi-Pot testing
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 to overvoltages due to switching of inductive loads such as motors. These overvoltages are NORMAL and, to some extent, predictable. Many studies have been published on the magnitude, duration, and repetition of these overvoltages. Safety insulations in primary circuits must be able to withstand these NORMAL overvoltages. Hence, the hi-pot type test is one measure of the adequacy of the primary circuit safety insulations to withstand these NORMAL overvoltages. The hi-pot type test does not in any way imply reliability of the solid insulation. Failure of solid insulation due to impressed voltage starts with partial discharges in voids in the insulation. Reliability is a function of the magnitude of voltage across any void. The smaller the void, the more reliable the insulation. A perfectly homogeneous solid insulation is very reliable with respect to the impressed voltage. (Many solid insulations approach perfect homogeniety.) An overvoltage limiting device, i.e., surge protector, can limit the magnitude of voltage across a safety insulation. This in turn limits the magnitude of voltage across any void in the insulation. The lower the voltage across any void, the lower the magnitude of partial discharge and the longer the life of the solid insulation. In practice, however, for typical mains over- voltages, the magnitudes, durations, and repetition rates together with the homogeniety of the insulation are such that damage due to partial discharge almost never causes catastrophic solid insulation failure in the lifetime of the product. Best regards, Rich This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Hi-Pot testing
After the surge protection components are disconnected, and the unit is hipotted and reassembled, a test of the surge protection circuit might be a good step. Dave Cuthbert Micron Technology From: Cole, Bryan [LBRT/CCC] [mailto:bryan.c...@control-concepts.com] Sent: Wednesday, September 03, 2003 5:25 AM To: 'Chris Maxwell '; 'EMC-PSTC Internet Forum ' Subject: RE: Hi-Pot testing Chris, As a manufacturer of surge protection devices, I can relate to what you have experienced. In the safety testing of the design, a hi-pot is performed to without the surge components to ensure a good design. In product, we have three different requirements from our safety agencies (UL and CSA). 1. No hipot is required as it was performed on the initial design. (DO NOT LIKE THIS ONE) 2. Hi-pot the product before the surge components are installed. 3. Hi-pot the product using a power supply with a limited current of 1 mA. Requirements 2 and 3 work well. With your set-up of a MOV/GDT, you may experience some problems with Requirement 3 unless you have balanced the capacitance between the MOV/GDT. Until the capacitance was balanced between these devices, our product failure rate in hi-pot remained high. Once the capacitance of the MOV/GDT has been balanced, you also have to re-examine the surge response. If you have any questions, please let me know. Thanks, Bryan. This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Hi-Pot testing
Chris, As a manufacturer of surge protection devices, I can relate to what you have experienced. In the safety testing of the design, a hi-pot is performed to without the surge components to ensure a good design. In product, we have three different requirements from our safety agencies (UL and CSA). 1. No hipot is required as it was performed on the initial design. (DO NOT LIKE THIS ONE) 2. Hi-pot the product before the surge components are installed. 3. Hi-pot the product using a power supply with a limited current of 1 mA. Requirements 2 and 3 work well. With your set-up of a MOV/GDT, you may experience some problems with Requirement 3 unless you have balanced the capacitance between the MOV/GDT. Until the capacitance was balanced between these devices, our product failure rate in hi-pot remained high. Once the capacitance of the MOV/GDT has been balanced, you also have to re-examine the surge response. If you have any questions, please let me know. Thanks, Bryan. From: Chris Maxwell To: EMC-PSTC Internet Forum Sent: 8/28/03 11:45 AM Subject: Hi-Pot testing All, We have a product that runs from AC power. 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 requires repair. The unit does meet surge test requirements. (EN 61000-4-5, Class II). The unit has surge protection circuitry installed from line to earth (MOV in line with a gas tube). This surge protection is disabled before the hipot test. So, here are a few of my random thoughts on this process. 1. I can't break every unit by hipot testing it before I ship it. 2. When the unit is in the field, it will have the surge protection installed, which will essentially limit any "real life hipot" voltages to about 500V (230V gas tube, 275VAC MOV). In real life, the unit would experience a maximum 500V hipot. However, in the case of a single fault (surge protection disabled), the unit could experience higher hipot voltages, which would cause damage, but not an unsafe condition (as shown by type testing). 3. The surge protection is not easily removed for hipot and then reinstalled after hipot. So...are there any alternative test or inspection methods that can be used on this product? Thanks in advance, Chris Maxwell | Design Engineer - Instruments Group email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Hi-Pot testing
Chris, Does this product have resistive voltage dividers that cross the isolation boundary, or something similar? Without know the specifics of your product, I can offer only a couple of suggestions. I have seen cases where the hipot causes damage but and the product is in full compliance with the safety requirements. Hipot was never intended to cause damage and it is generally permissible to disconnect any transient suppression devices or feedback circuits that may otherwise interfere with the test. Good judgment must be used in opening these circuits while doing the test. You may find the entire hipot potential impressed across the circuit opening you created and often there is not enough spacing to isolate the test voltage. You get an arc over. The other concern is, if you must temporarily disconnect surge suppression devices, there has to be a quality check to insure that these devices are reestablished prior to shipment of the product. The other situation is where you may have a voltage divider string that experienced too much power during the test. Some safety standards allow you to drop the test time to a much shorter duration by adding 20% to the test voltage. The power dissipation is then minimized by time. -doug Douglas E. Powell Corporate Compliance Dept. Advanced Energy Industries, Inc. Fort Collins, CO 80535 USA From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Thursday, August 28, 2003 9:45 AM To: EMC-PSTC Internet Forum Subject: Hi-Pot testing All, We have a product that runs from AC power. 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 requires repair. The unit does meet surge test requirements. (EN 61000-4-5, Class II). The unit has surge protection circuitry installed from line to earth (MOV in line with a gas tube). This surge protection is disabled before the hipot test. So, here are a few of my random thoughts on this process. 1. I can't break every unit by hipot testing it before I ship it. 2. When the unit is in the field, it will have the surge protection installed, which will essentially limit any "real life hipot" voltages to about 500V (230V gas tube, 275VAC MOV). In real life, the unit would experience a maximum 500V hipot. However, in the case of a single fault (surge protection disabled), the unit could experience higher hipot voltages, which would cause damage, but not an unsafe condition (as shown by type testing). 3. The surge protection is not easily removed for hipot and then reinstalled after hipot. So...are there any alternative test or inspection methods that can be used on this product? Thanks in advance, Chris Maxwell | Design Engineer - Instruments Group email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ___ This message, including any attachments, may contain information that is confidential and proprietary information of Advanced Energy Industries, Inc. The dissemination, distribution, use or copying of this message or any of its attachments is strictly prohibited without the express written consent of Advanced Energy Industries, Inc. This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Hi-Pot testing
I read in !emc-pstc that Chris Maxwell wrote (in <83d652574e7af740873674f9fc12dbaa0189d...@utexh1w2.gnnettest.com>) about 'Hi-Pot testing' on Thu, 28 Aug 2003: >The hipot test burned out the rectifier. Well, it absolutely ought not to have done. The hipot test is applied between all primary circuits and all secondary circuits. There is no way this should fire the gas tubes. You haven't grounded the cold ends of the gas tubes, by any chance? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Hi-Pot testing
Chris, do they really need the gas tubes and MOV's or are these components someone's "insurance" or empirical engineering? Dave Cuthbert Micron Technology From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Thursday, August 28, 2003 1:38 PM To: Rich Nute Cc: emc-p...@majordomo.ieee.org Subject: RE: Hi-Pot testing Thanks for the response. It's hard to say. I wasn't there for the hipot test. I just saw the aftermath. A little background: The unit under test had a power supply which we designed from off the shelf building blocks. The first building block is a rectifier/doubler, which takes the AC input and rectifies it. The rectifier also has some "smarts" which kick in a doubler for input voltages under 180VAC. The output of the rectifier is always about 320VDC. This 320VDC is split into two rails of 160VDC each so that 200V, low profile capacitors can be used. Each of these split rails is protected by a 230V gas tube. The 320VDC is then used by high voltage DC/DC converters (purchased modules) which make 5V and 12V. The hipot test burned out the rectifier. My guess is that the gas tubes on the output fired. Since they have such a high instantaneous current draw, the recitifier could be momentarily overloaded. Even the fuse in front of the rectifier (it did blow) could not protect the rectifier from the hard blow characteristic of the gas tubes. We could populate the circuitboard without the gas tubes, assemble the unit, hipot test it and then install the gas tubes. However, to me, this would seem to make the hipot test superfluous. The amount of re-assembly required to re-install the gas tubes would make the initial hipot test a waste of time. There would be all sorts of chances for somebody to drop a screw into the unit, or leave one out. Is there a way that the subassemblies could be hipot tested, then the main assembly could have a low voltage hipot just to check for the ubiquitous "dropped screw"? Chris Maxwell | Design Engineer - Instruments Group email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | > -Original Message- > From: Rich Nute [SMTP:ri...@sdd.hp.com] > Sent: Thursday, August 28, 2003 1:31 PM > To: Chris Maxwell > Cc: emc-p...@majordomo.ieee.org > Subject: Re: Hi-Pot testing > > > > > 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 requires repair. > > I have two questions: > > 1. Is the functional failure due to over-voltage > of a component? > > Or > > 2. Is the functional failure due to the hi-pot > "leakage" current between primary and secondary? > > If 1, then you should be able to disconnect that > component during the test. Or, you could use the > solution for 2. > > If 2, then the problem becomes much more complex. > We test the board before it goes into the product > using a "bed of nails" that equalizes the potential > on throughout the primary and throughout the > secondary. This prevents current through the > components, yet tests the isolation between primary > and secondary. > > Of course, such a test does not test the board in > the end-product, which is a problem if the enclosure > is metal. > > Without more details of your circuit and the parts > which are broken, I cannot give you further advice. > > > Best regards, > Rich > > > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line:
RE: Hi-Pot testing
Thanks for the response. It's hard to say. I wasn't there for the hipot test. I just saw the aftermath. A little background: The unit under test had a power supply which we designed from off the shelf building blocks. The first building block is a rectifier/doubler, which takes the AC input and rectifies it. The rectifier also has some "smarts" which kick in a doubler for input voltages under 180VAC. The output of the rectifier is always about 320VDC. This 320VDC is split into two rails of 160VDC each so that 200V, low profile capacitors can be used. Each of these split rails is protected by a 230V gas tube. The 320VDC is then used by high voltage DC/DC converters (purchased modules) which make 5V and 12V. The hipot test burned out the rectifier. My guess is that the gas tubes on the output fired. Since they have such a high instantaneous current draw, the recitifier could be momentarily overloaded. Even the fuse in front of the rectifier (it did blow) could not protect the rectifier from the hard blow characteristic of the gas tubes. We could populate the circuitboard without the gas tubes, assemble the unit, hipot test it and then install the gas tubes. However, to me, this would seem to make the hipot test superfluous. The amount of re-assembly required to re-install the gas tubes would make the initial hipot test a waste of time. There would be all sorts of chances for somebody to drop a screw into the unit, or leave one out. Is there a way that the subassemblies could be hipot tested, then the main assembly could have a low voltage hipot just to check for the ubiquitous "dropped screw"? Chris Maxwell | Design Engineer - Instruments Group email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | > -Original Message- > From: Rich Nute [SMTP:ri...@sdd.hp.com] > Sent: Thursday, August 28, 2003 1:31 PM > To: Chris Maxwell > Cc: emc-p...@majordomo.ieee.org > Subject: Re: Hi-Pot testing > > > > > 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 requires repair. > > I have two questions: > > 1. Is the functional failure due to over-voltage > of a component? > > Or > > 2. Is the functional failure due to the hi-pot > "leakage" current between primary and secondary? > > If 1, then you should be able to disconnect that > component during the test. Or, you could use the > solution for 2. > > If 2, then the problem becomes much more complex. > We test the board before it goes into the product > using a "bed of nails" that equalizes the potential > on throughout the primary and throughout the > secondary. This prevents current through the > components, yet tests the isolation between primary > and secondary. > > Of course, such a test does not test the board in > the end-product, which is a problem if the enclosure > is metal. > > Without more details of your circuit and the parts > which are broken, I cannot give you further advice. > > > Best regards, > Rich > > > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Hi-Pot testing
> 2. When the unit is in the field, it will have the surge protection installed, > which will essentially limit any "real life hipot" voltages to about 500V (230V > gas tube, 275VAC MOV). In real life, the unit would experience a maximum 500V > hipot. However, in the case of a single fault (surge protection disabled), the > unit could experience higher hipot voltages, which would cause damage, but not an > unsafe condition (as shown by type testing). 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. Thanks, Sam This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Hi-Pot testing
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 requires repair. I have two questions: 1. Is the functional failure due to over-voltage of a component? Or 2. Is the functional failure due to the hi-pot "leakage" current between primary and secondary? If 1, then you should be able to disconnect that component during the test. Or, you could use the solution for 2. If 2, then the problem becomes much more complex. We test the board before it goes into the product using a "bed of nails" that equalizes the potential on throughout the primary and throughout the secondary. This prevents current through the components, yet tests the isolation between primary and secondary. Of course, such a test does not test the board in the end-product, which is a problem if the enclosure is metal. Without more details of your circuit and the parts which are broken, I cannot give you further advice. Best regards, Rich This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Hi-Pot testing
Chris, I wasn't real clear on what was "breaking" during your hipot test. However, these comments might help: 1) Be sure you are hipot testing with a DC test voltage. AC testing can damage your Y capacitors. DC test voltage = peak of AC test voltage = 1.414 x AC test voltage. 2) If your product incorporates a surge protector (i.e. MOV), you are permitted to remove the device or lift one leg so that it is not in the circuit during the test. 3) Waiving the test is usually not an option with the Certification lab. However, adjusting the test to prevent damage (such as removing the MOV) is typically permitted. If these don't solve your problem, provide more details on the damage & perhaps I/someone can provide additional input. Regards, Bill Bisenius E.D.& D. bi...@productsafet.com -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Thursday, August 28, 2003 11:45 AM To: EMC-PSTC Internet Forum Subject:Hi-Pot testing All, We have a product that runs from AC power. 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 requires repair. The unit does meet surge test requirements. (EN 61000-4-5, Class II). The unit has surge protection circuitry installed from line to earth (MOV in line with a gas tube). This surge protection is disabled before the hipot test. So, here are a few of my random thoughts on this process. 1. I can't break every unit by hipot testing it before I ship it. 2. When the unit is in the field, it will have the surge protection installed, which will essentially limit any "real life hipot" voltages to about 500V (230V gas tube, 275VAC MOV). In real life, the unit would experience a maximum 500V hipot. However, in the case of a single fault (surge protection disabled), the unit could experience higher hipot voltages, which would cause damage, but not an unsafe condition (as shown by type testing). 3. The surge protection is not easily removed for hipot and then reinstalled after hipot. So...are there any alternative test or inspection methods that can be used on this product? Thanks in advance, Chris Maxwell | Design Engineer - Instruments Group email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: hi pot testing
Richard, I am not familiar with prEN50116 either. However I am confident that with few exceptions UL and CSA procedure holders will find that hipot testing is required. UL controls the hipot tester by manufacturer and model in an Appendix located at the front of each Volume of the procedure. Why they put an Appendix at the front is another question I can't address. Most EN standards do not have production line hipot requirements; however most holders of TUV licenses have no doubt been informed of production hipot and high current ground continuity testing requirements during their first inspection. NEMKO also has internal requirements requiring production hipot and high current ground tests on many types of products. Their requirements state they will become superceded upon adoption of harmonized CENELEC test requirements, which hopefully is what prEN50116 will be. As far as production line test requirements for holders of CE marking self declaration documents, who knows? As you, I await the group's reception of this note with bated breath. Jeff Lind Compliance West >Recently I have seen some questions in this group regarding hi-pot testing >and IEC1010 and prEN50116. > >I am not familiar with prEN50116 (perhaps someone can enlighten me about >that), but I am familiar with IEC1010 and hi-pot testing. > >In amendment 2 to IEC1010 Annex K changes from Informative to Normative >(becomes required). This Annex describes the routine manufacturing line >testing for products which includes hi-pot testing. I am sure that this >will be added to the harmonized equivalents as well, ANSI/ISA S82.01, CSA >1010.1, EN61010-1, and UL3111-1. > >Also, I believe that hi-pot testing is required by UL as well as CSA in the >majority of their electronic product categories. It may be in the Section >General or in an Appendix rather than in the Section which describes the >product, but I feel sure that UL believes that it is required. > >It would also surprise me if organizations like VDE and TUV don't also feel >that hi-pot testing is a requirement. I believe that we would be doing >hi-pot testing at this company whether it was required by the standard or >not, because we feel it is a good thing to do. > >If my understandings here are not accurate, I am confident that someone >will now let me know. > > >Richard Payne >Tektronix, Inc. >richard.pa...@tek.com > >
