Thanks to the folks that have replied so far. Here's my dilemma, the EFT standard says:
If the manufacturer provides a non-detachable supply cable more than 0,5 m ± 0,05 m long with the equipment, the excess length of this cable shall be folded to avoid a flat coil and situated at a distance of 0,1 m above the ground reference plane. Surge is similar. However, CI is not. On all cables to be tested, coupling and decoupling devices shall be inserted (see 7.1.2). The coupling and decoupling devices shall be placed on the ground reference plane, making direct contact with it at a distance of 0,1 m to 0,3 m from the EUT. The cables between the coupling and decoupling devices and the EUT shall be as short as possible and shall not be bundled or wrapped. Their height above the ground reference plane shall be between 30 mm and 50 mm. So what this is telling me, I believe, is that the Surge and EFT must be done first with the manufacturer supplied cable ( Or the connection remade ) and the cable bundled non-inductively. For CI, regardless of supplied cable length, the cable must be cut to the minimum practical length. I hear what is said about robust EUT's, but the requirement is to follow the standard.... I think I have my answer... Thanks everyone, Derek Walton L F Research -----Original Message----- From: Spencer, David H <[email protected]> To: Derek Walton <[email protected]>; [email protected] Sent: Tue, Feb 8, 2011 1:39 pm Subject: RE: EUT power cord length The obvious question: does it make a difference with respect to test results between .5M and 5M? If the EUT is sufficiently robust, it may not make a difference. If you determine a worse case I would go with that. Of course, hacking bits off at a time may not make the customer happy. You could just directly inject into the in-let terminals of the EUT (I'm sure that's coming in a future revision of IEC 61000-4-4). ;) Regards, David Spencer EH&S EMC Engineer Xerox Corp -----Original Message----- From: [email protected] on behalf of Derek Walton Sent: Tue 2/8/2011 2:22 PM To: [email protected] Subject: EUT power cord length Hi Group, I have a question concerning what to do with an EUT's non detaching power cord for EFT, Surge and CI. Lets say the EUT comes with 5 metres of cable, what would I do with this cable between the coupling networks and the EUT? Do I cut to a shorter length, bundle etc? I'm stressing non detaching power cord.... Opinions welcome. Thanks, Derek Walton - ---------------------------------------------------------------- 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://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. 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://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. 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]>
