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. Wellll.... 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" <[email protected]> >To: "[email protected]" <[email protected]> >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 ><[email protected]> > >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 <[email protected]> >Mike Cantwell <[email protected]> > >For policy questions, send mail to: >Jim Bacher: <[email protected]> >David Heald: <[email protected]> > > > - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
