Re: [PSES] Capacitor Discharge Test IEC 61010-1 - A little history
Brian, et al, A histerical, er - historical, review... In an internationally harmonized standard all expected issues must be considered. The primary driving factor for the cap discharge test on the power input pins has been driven by the British over the years. The large, 13A British power plug behaves differently than the North American or Euro (or similar) plugs. When you pull a NA plug from the wall and drop it in your hand the pins are parallel to your palm and spaced away from you hand by the plug insulation (envision it in your mind as it is described). Whether or not a voltage exists on the pin is not usually important, the person holding the plug will not know if the voltage exists there. The large, flat British plug seems to follow the 'perversity of nature' rule and drop 'butter side down' with the pins in the palm of your hand most of the time - thereby providing the shocking experience which is deemed adequate to need mitigation. Hence the test to limit the sensation to that which is acceptable. I remember British colleagues on the committee pressing to have this requirement properly included during standards harmonization discussion in another standard. History has never been a strong interest among most engineers so I'm not surprised that small facts such as this fall away with time. :) br, Pete Peter E Perkins, PE Principal Product Safety Engineer PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 fone/fax p.perk...@ieee.org - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Capacitor Discharge Test IEC 61010-1 - A little history
In message 34C449781DB0418B8509F64FA4FA3967@Pete97219Compaq, dated Mon, 27 May 2013, Pete Perkins peperkin...@cs.com writes: The large, flat British plug seems to follow the 'perversity of nature' rule and drop 'butter side down' with the pins in the palm of your hand most of the time - thereby providing the shocking experience which is deemed adequate to need mitigation. It needs mitigation because consumers complained about it and often tried to reject the product as 'unsafe'. It's not only our lovely 13 A plug that drops 'butter side down', the Continental Schuko plug and its relatives do it. -- OOO - Own Opinions Only. See www.jmwa.demon.co.uk Why does everything require an odd number of opamps? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Capacitor Discharge Test IEC 61010-1
Hi Brian: According to 6.10.3 and 6.3.1, the requirement is: At 5 seconds, if the voltage exceeds 70 volts, the charge must not exceed 45 uC. Figure 3, Line A, is simply a 45 uC line as a function of capacitance and voltage. This line is derived from the formula: q = C * V where q is the charge in coulombs C is the capacitance in Farads V is the voltage in volts You have 80 volts and 4.4 uF: q = 4.4 * 10^-6 * 80 q = 352 uC You guessed right! The test is performed at the maximum rated input voltage. This give the worst-case voltage. Best regards, Rich On 5/21/2013 9:33 AM, Kunde, Brian wrote: What we call the Capacitor Discharge Test in the IEC 61010-1 standard section 6.10.3 says that voltage across the pins of the power cord must not be Hazardous Live 5 seconds after disconnection from the supply. Most labs simply check to see if the voltage across the pins are 60 volts or less at 5 seconds, but the pass/fail criteria is the capacitive charge level described in 6.3.1 c) which is 45uC. 6.3.1 c) points you to Line A of Figure 3 but this chart seems to start at 100 volts. So how do I apply this chart if my 5 second voltage is 80 volts? Am I looking at this wrong or should this chart go down to at least 60 volts? Is there a formula that can be used instead of the chart? In our specific case, we are measuring the discharge of an RF line filter which has 4.4uF of capacitance across the line and the 5 second voltage is 80 volts. My guess would be this filter fails as-is without and additional bleeder resistor but when I discuss it with the company they pick apart the standard and the chart at figure 3. Another question. When you perform this test what line voltage do you use? The highest nominal voltage or do you include +10%? For 230VAC equipment do you test at 230Vrms or 264Vrms (373Vpk)? Thanks to all for any input. The Other Brian - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Capacitor Discharge Test IEC 61010-1
Bill, Thanks for the reply. I guess different product safety standard has different requirements for the voltage on plug pins. I think that the IEC 60950 standard requires the pin voltage to drop below 37% of the peak voltage within the first second. We always did the 60 volt 5 second test for Laboratory Equipment. Maybe the standards writers think people who work in a lab is smart enough not to touch the pins or that they can handle shocks without mutating into a super hero. (I see a movie plot developing here). What gets me scratching my head is the chart on Figure 3 and why is starts at 100 volts. Am I to interpret the requirements to mean that if my 5 second voltage is below 100 volts that I can assume it passes? If so, I would really like to know. Can any of you safety expects help me out on this? Thanks, The Other Brian From: Bill Owsley [mailto:wdows...@yahoo.com] Sent: Tuesday, May 21, 2013 10:50 PM To: Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: Capacitor Discharge Test IEC 61010-1 A few decades ago when an intern, called co-op back then, a customer complaint came in that they had been shocked by the power plug after pulling it from the wall. No way said the engineers! Hey co-op go test this. We it turns out there can be the peak voltage left on the pins of the plug which will decay depending on the environment. And so the bleeder resistor. I thought the time frame was on the order of 250 mS. How fast can an operator get their fingers on the plug pins after pulling out? Sticking their fingers on a partial pulled plugged was dis-allowed. But those details were for the Safety engineers. From: Kunde, Brian brian_ku...@lecotc.commailto:brian_ku...@lecotc.com To: EMC-PSTC@LISTSERV.IEEE.ORGmailto:EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORGmailto:EMC-PSTC@LISTSERV.IEEE.ORG Sent: Tuesday, May 21, 2013 12:33 PM Subject: Capacitor Discharge Test IEC 61010-1 What we call the Capacitor Discharge Test in the IEC 61010-1 standard section 6.10.3 says that voltage across the pins of the power cord must not be Hazardous Live 5 seconds after disconnection from the supply. Most labs simply check to see if the voltage across the pins are 60 volts or less at 5 seconds, but the pass/fail criteria is the capacitive charge level described in 6.3.1 c) which is 45uC. 6.3.1 c) points you to Line A of Figure 3 but this chart seems to start at 100 volts. So how do I apply this chart if my 5 second voltage is 80 volts? Am I looking at this wrong or should this chart go down to at least 60 volts? Is there a formula that can be used instead of the chart? In our specific case, we are measuring the discharge of an RF line filter which has 4.4uF of capacitance across the line and the 5 second voltage is 80 volts. My guess would be this filter fails as-is without and additional bleeder resistor but when I discuss it with the company they pick apart the standard and the chart at figure 3. Another question. When you perform this test what line voltage do you use? The highest nominal voltage or do you include +10%? For 230VAC equipment do you test at 230Vrms or 264Vrms (373Vpk)? Thanks to all for any input. The Other Brian LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald: dhe...@gmail.commailto:dhe...@gmail.com LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to
[PSES] Capacitor Discharge Test IEC 61010-1
What we call the Capacitor Discharge Test in the IEC 61010-1 standard section 6.10.3 says that voltage across the pins of the power cord must not be Hazardous Live 5 seconds after disconnection from the supply. Most labs simply check to see if the voltage across the pins are 60 volts or less at 5 seconds, but the pass/fail criteria is the capacitive charge level described in 6.3.1 c) which is 45uC. 6.3.1 c) points you to Line A of Figure 3 but this chart seems to start at 100 volts. So how do I apply this chart if my 5 second voltage is 80 volts? Am I looking at this wrong or should this chart go down to at least 60 volts? Is there a formula that can be used instead of the chart? In our specific case, we are measuring the discharge of an RF line filter which has 4.4uF of capacitance across the line and the 5 second voltage is 80 volts. My guess would be this filter fails as-is without and additional bleeder resistor but when I discuss it with the company they pick apart the standard and the chart at figure 3. Another question. When you perform this test what line voltage do you use? The highest nominal voltage or do you include +10%? For 230VAC equipment do you test at 230Vrms or 264Vrms (373Vpk)? Thanks to all for any input. The Other Brian LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Capacitor Discharge Test IEC 61010-1
A few decades ago when an intern, called co-op back then, a customer complaint came in that they had been shocked by the power plug after pulling it from the wall. No way said the engineers! Hey co-op go test this. We it turns out there can be the peak voltage left on the pins of the plug which will decay depending on the environment. And so the bleeder resistor. I thought the time frame was on the order of 250 mS. How fast can an operator get their fingers on the plug pins after pulling out? Sticking their fingers on a partial pulled plugged was dis-allowed. But those details were for the Safety engineers. From: Kunde, Brian brian_ku...@lecotc.com To: EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Sent: Tuesday, May 21, 2013 12:33 PM Subject: Capacitor Discharge Test IEC 61010-1 What we call the Capacitor Discharge Test in the IEC 61010-1 standard section 6.10.3 says that voltage across the pins of the power cord must not be Hazardous Live 5 seconds after disconnection from the supply. Most labs simply check to see if the voltage across the pins are 60 volts or less at 5 seconds, but the pass/fail criteria is the capacitive charge level described in 6.3.1 c) which is 45uC. 6.3.1 c) points you to Line A of Figure 3 but this chart seems to start at 100 volts. So how do I apply this chart if my 5 second voltage is 80 volts? Am I looking at this wrong or should this chart go down to at least 60 volts? Is there a formula that can be used instead of the chart? In our specific case, we are measuring the discharge of an RF line filter which has 4.4uF of capacitance across the line and the 5 second voltage is 80 volts. My guess would be this filter fails as-is without and additional bleeder resistor but when I discuss it with the company they pick apart the standard and the chart at figure 3. Another question. When you perform this test what line voltage do you use? The highest nominal voltage or do you include +10%? For 230VAC equipment do you test at 230Vrms or 264Vrms (373Vpk)? Thanks to all for any input. The Other Brian LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
