RE: 61000-4-8 Ground Plane
Bob, The standard (in the definitions section) only says that the ground plane "is used as a common reference for the magnetic field generator and the auxiliary equipment", but I suspect that safety is a major reason for it being used. Without a good ground reference there is a possibility that dangerous potential differences could be created by the very strong power-frequency magnetic fields used. Naturally, the GRP must be of non magnetic material to prevent it from shunting some of the magnetic flux. Scott Lacey -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of rehel...@mmm.com Sent: Friday, June 16, 2000 10:32 AM To: emc-p...@majordomo.ieee.org Subject: 61000-4-8 Ground Plane Can someone explain to me why a ground plane is required in the test setup for EN 61000-4-8 (power frequency magnetic fields)? Thanks, Bob Heller 3M Company --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: 61000-4-8 Ground Plane
As the drawings show in EN61000-4-8, one way to achieve the required field is to let the ground plane be the fourth side of a square loop. I have found it more convenient to construct stand-alone loops that can be placed over and under the EUT which is supported above an appropriate ground plane. I would surmise that the requirement to ground one side of the loop is based on safety of the person performing the test. A multi-turn loop conceivably could require more than a few volts to achieve the required current flow to produce the desired magnetic field intensity. >Can someone explain to me why a ground plane is required in the test setup for >EN 61000-4-8 (power frequency magnetic fields)? > >Thanks, >Bob Heller >3M Company --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: 61000-4-8 Ground Plane
I don't know either I am assuming that they are just trying to standardize the test "cell" if you will. You're right the field of interest is inside the loop and the external lobs shouldn't be a problem whether or not the fringe with a ground plane or not, even if they did I think the ability would exist to increase the field strength for the EUT to compensate. I suppose there is something obviously wrong with my assumption but that wouldn't be the first time. Gary -Original Message- From: rehel...@mmm.com [mailto:rehel...@mmm.com] Sent: Friday, June 16, 2000 9:21 AM To: michael.sundst...@nokia.com Cc: emc-p...@majordomo.ieee.org Subject: RE: 61000-4-8 Ground Plane 61000-4-8 is an immunity test. It totally immerses the EUT in a magnetic field at 50 Hz. I still don't know what the ground plane is for. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: 61000-4-8 Ground Plane
On Fri, 16 June 2000, rehel...@mmm.com wrote: > Can someone explain to me why a ground plane is required in the test setup for > EN 61000-4-8 (power frequency magnetic fields)? > > Thanks, > Bob Heller > 3M Company --- Bob, Good question! The ground plane is described in the EN 61000-4-8 standard, but not used in many EMC testing labs. People cannot figure out the difference if using it in real test. However, there must be a reason to use it when the standard was written. Thanks. Best Regards, Barry Ma ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: 61000-4-8 Ground Plane
61000-4-8 is an immunity test. It totally immerses the EUT in a magnetic field at 50 Hz. I still don't know what the ground plane is for. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
61000-4-8 Ground Plane
Can someone explain to me why a ground plane is required in the test setup for EN 61000-4-8 (power frequency magnetic fields)? Thanks, Bob Heller 3M Company --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
