This type of testing is already defined and required in CISPR 24. Some years ago I tested surge tested many PC and minicomputer supplies using the 1.2/50 (8/20) bi wave 2 ohm source impedance. Most supplies would tolerate a 2000 to 2500 V pulse without damage. Above that, the power supply was disabled -- unless the supply had built in surge protection.
Building wiring does attenuate surge energy simply because a transient pulse on an external feeder will have a multitude of paths through the building wiring. And, if a damaging pulse does enter the building, rarely does it affect more than a few (maybe only one) devices which take the brunt of the energy from the pulse and tereby "protecting" other equipment. John P. Wagner AVAYA Communication 1300 W. 120th Ave, Room B3-D16 Phone/Fax: (303) 538-4241 [email protected] > ---------- > From: CE-test - Ing. Gert Gremmen - ce-marking and > more...[SMTP:[email protected]] > Reply To: CE-test - Ing. Gert Gremmen - ce-marking and more... > Sent: Wednesday, September 19, 2001 11:39 AM > To: Emc-Pstc@Ieee. Org > Subject: security and ITE > > <<File: Gert Gremmen.vcf>> > Group, > > I would like to start another discussion about ITE equipment and > security. > Reports and investigations have shown that ITE equipment > in almost any office is susceptible to transients applied to the > mains network OUTSIDE the building. Using relative small electronic > equipment on the market for EMC testing pulses can be injected that > could crash or even destroy the supply of a substantial of > the IT equipment (read PC) in that same building. Test were done > with products of reputable manufacturers. It made almost no > difference how the mains network was organized in terms of > switchboards > and how the IT equipment was supplied. The slow high energy pulses > came > trough almost unattenuated. > > At this very moment no immunity requirements exist for IT equipment in > many large economic areas in the world. Would this open up > a new field of interest for us EMC and Safety Engineers ? Or would > the topic be grasped by less scrupulous individuals in the world > before we got hands on this ? > > What do YOU think ! And how could we change that risk in time ? > Do we need to protect the mains networks or the IT equipment ? > > What other vulnerabilities exist in our current IT system world wide ? > > Regards, > > Gert Gremmen, (Ing) > > ce-test, qualified testing > > =============================================== > Web presence http://www.cetest.nl > CE-shop http://www.cetest.nl/ce_shop.htm > /-/ Compliance testing is our core business /-/ > =============================================== >
