You'll need to get a copy of IEC (or EN) 61000-4-5 which shows how the test is done. You're correct about the coupling -- line to PE for I/O lines, but NOT coupled via an inductive clamp. You'll need some kind of coupler/decoupler appropriate to the line your testing. For most I/O lines with data rates of 100kHz or less, couplers are available commercially that will work with most surge generators (we make some). For higher data rates, most couplers won't work because the frequency of what you want to pass is approaching the frequency of what you want to block!! The latest (unpublished) draft of a 61000-4-5 revision recommends testing I/O ports directly if the data rates are higher than 100kHz. Inductive clamps for surges simply don't work. The standard (61000-4-5) shows some recommended coupling methods using capacitive coupling (if the line inputs can stand the 0.5uF capacitance) or arrestor coupling (much lower capacitance). Hope this is helpful. Best Regards,
Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC & ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 [email protected] www.thermo.com/esd One Thermo, committed to integrity, intensity, innovation & involvement From: Sam Wismer [mailto:[email protected]] Sent: Friday, December 19, 2003 9:38 AM To: EMC 2 Subject: Surge on signal lines Hello All, I have a product in which the customers can envision the user to use a signal cable longer than 30m. He has no control over what is used and the product will function with a cable of that length. The standard I am testing to is EN 61000-6-2. The requirement for signal lines says the surge on I/O lines must be performed >from line to earth at 1kV. Silly question I suppose, but what is meant by line and what is meant by earth? I suppose line is the signal line and earth is protective earth. Also, I assume the surge must be induced by an inductive clamp. My question is how is the surge applied between the signal line and earth when using a clamp? Kind Regards, Sam Wismer Engineering Manager ACS, Inc. *Tel: (770) 831-8048 *Fax: (770) 831-8598 *Web: www.acstestlab.com <mailto:*[email protected]> *[email protected]
