Gus, This is a complicated subject and people go to school for this sort of stuff. The simple answers are found in a number of equations that primarily take into account electrode spacing and electrode geometry. Considerations are also dielectric medium, air pressure, humidity, and to a lesser extent electrode materials. There is no single equation you can use. However, there are a number of resources I can recommend, the challenge is finding these in print. "High Voltage Power Supply Design" by John A Collins, Hughes Aircraft Co. circa 1980s "Design Considerations and Data for Gas-Insulated High Voltage Structures" D. B. Hopkins, Lawrence Berkeley Laboratory circa 1970s "High Voltage Technology", edited by L. L. Alston Harwell, Post-Graduate Series, Oxford University Press 1968 Regards, -doug ------------------------------------- Douglas E. Powell Corporate Compliance Dept. Advanced Energy Industries, Inc. Fort Collins, CO 80525 USA -----Original Message----- From: gustavo.duenas@xxxxxxxxxxx [mailto:gustavo.duenas@xxxxxxxxxxx] Sent: Tuesday, November 04, 2003 9:03 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] breakdown voltage (arching) equation Hello all , Does anyone know of an equation that relates breakdown voltage (arching) vs distance in a given dielectric medium, metal types ,etc? I looked in Henry Ott's book but did not find an equation. Thanks in advance, Gus _______________________________________________________________ This message, including any attachments, may contain information that is confidential and proprietary information of Advanced Energy Industries, Inc. The dissemination, distribution, use or copying of this message or any of its attachments is strictly prohibited without the express written consent of Advanced Energy Industries, Inc. ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu