Interesting. I have done the testing with the bleeder cable as described connected in parallel, not in series with the HCP bleeder. Maybe I was doing it wrong though? But as you said, it does not make sense-but does it make a difference? Is it shown as set up that way merely as a closer more convenient connection to the EUT? Reading the text and ignoring figure 6 would lead me to believe it was in parallel.
______________________________________________________ Dan Roman, N.C.E. VP of Communications Services IEEE Product Safety Engineering Society mailto:[email protected] From: McInturff, Gary [mailto:[email protected]] Sent: Wednesday, March 06, 2013 6:20 PM To: [email protected] Subject: [PSES] test setup for table top ungrounded equipment 61000-4-2 IEC:2008 figure 6 page 20 Ladies and germs I was confirming this set-up and found something confusing. The picture shows the cable which is used to remove charge from the EUT between successive ESD discharges and having 2 470k Ohm resistors, the same basic setup as between HCP and ground plane or VCP and ground plane. Not surprising, but in looking at the picture it implies that this cable ends up being in series with the HCP/GP bleeder cable. That would make the series resistance during discharge to be rough 2 Mohm rather than 1 Mohm. That doesn't seem right to me. The reference text doesn't really what happens to the hcp discharge cable either. In fact the cable for the VCP would seem to be placed in parallel with the HCP bleeder cables during indirect contact discharges to the VCP. I don't believe that is true either. I believe for the VCP setup the HCP cable is disconnected from the HCP and then hooked up to the VCP. I kind of expected the bleeder cable for the ungrounded equipment bleeder cable would do the same thing. The HCP cable removed and it could be used as the EUT bleeder resistor wire as well. In the first case the bleeder and the HCP bleeder cable appear to be in series, and in the second the bleeder and the HCP would be in parallel if it wasn't disconnected from the HCP. I do have a pdf of the figure but not allowed to attach to this email. Thoughts. Gary McInturff Reliability/Compliance Engineer Esterline Interface Technologies Featuring ADVANCED INPUT, GAMESMAN, LRE MEDICAL, and MEMTRON products 600 W. Wilbur Avenue Coeur d'Alene, ID 83815-9496 Toll Free: 800-444-5923 X1XXX Tel: (208) 635-8 Fax: (208) 635-8 www.esterline.com/interfacetechnologies Technology, Innovation, Performance. Click <http://www.esterline.com/governance/email_disclaimer/tabid/1532/Default.asp x> here to read disclaimer - ---------------------------------------------------------------- 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]>
